Bas-Apg007-En 12012009 Air Systems

December 2009 BAS-APG007-EN

Applications Guide

Air Systemsfor Tracer™ SC

©2009 Trane. All Rights Reserved. BAS-APG007-EN, 12/15/2009 PROPRIETARY INFORMATION OF TRANE. 1

MAY ONLY BE USED IN THE CONDUCT OF TRANE BUSINESS.

Copyright

© 2009 Trane All rights reserved

This document and the information in it are the property of Trane and may not be used or reproduced in whole or in part, without the written permission of Trane. Trane reserves the right to revise this publication at any time and to make changes to its content without obligation to notify any person of such revision or change.

Trademarks

Trane and its logo are trademarks of Trane in the United States and other countries. All trademarks referenced in this document are the trademarks of their respective owners.

Warnings, Cautions, and Notices

Warnings, cautions, and notices are provided in appropriate places throughout this document:

WARNING: Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION: Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. It may also be used to alert against unsafe practices.

NOTICE: Indicates a situation that may result in equipment or property-damage- only accidents.

2 BAS-APG007-EN, 12/15/2009

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Who Does What and When? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Some Assumptions About the Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

VAV Air System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Building Automation System (BAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Tracer SC Variable-Air-Volume Air System Benefits . . . . . . . . . . . . . . . . . . . 11

Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Air Handling Unit (AHU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

VAV Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

How VAV Boxes Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Single-Duct VAV Terminal Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Parallel Fan-Powered Terminal Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Series Fan-Powered Terminal Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

How the Air Handler Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Variable Volume Air Handling Units (VAV AHUs) . . . . . . . . . . . . . . . . . . . . . . 23

How the System Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Zone Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Installing the VAV Discharge Air Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Installing a Hot Water Valve (Local Heat and Remote Heat) . . . . . . . . . . . . . 30

Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Power Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Air Handler Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Controller Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Air Handler Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Why Use a DAC Profile for an Air Handler on a LonTalk Link? . . . . . . . . . . . 33

Pre-Configuration Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

General LonTalk Controller Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Controller Setup (IntelliPak) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

VAV Box Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Field-applied Controller Programming for Variable Volume and Constant Volume Air Handlers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Programming the MP580/581 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Enabling Profiles for the MP580/581 Object . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Configure the Inputs/Outputs/Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

BAS-APG007-EN, 12/15/2009 3

Install the MP580/581 on the Tracer SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Integrating the MP580/581 Controller with Tracer SC . . . . . . . . . . . . . . . . . . 51

Communicating Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Tracer Graphical Programming (in the MP580/581 using Rover) . . . . . . . . . 57

Pre-Packaged Solutions Sample PPS Graphics.tgp . . . . . . . . . . . . . . . . . . . . 58

Programming the Field-Applied BACnet Unit Controllers . . . . . . . . . . . . . . . 59

VAV System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Common Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Defining Areas and Selecting Area Members . . . . . . . . . . . . . . . . . . . . . . . . . 62

Assigning the VAS Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

How Area and VAS Interact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

How Schedule and Area Determine Operating Mode . . . . . . . . . . . . . . . . . . 68

How Area Determines the Operating Mode of the VAV Box . . . . . . . . . . . . . 71

Tracer SC Application Setup for Variable Air Systems . . . . . . . . . . . . . . 72

Tracer SC Equipment Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Install and Set Up the Variable Air Volume Equipment Types . . . . . . . . . . . 73

Set Up Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Navigating Through the VAS Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

VAV Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Auto-Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Commissioning and Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Standard Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Unoccupied Heating/Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Optimal Start (PreCool/Morning Warm-up . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Humidity Pull Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Warm-up with Normal Start (No Optimal Start) . . . . . . . . . . . . . . . . . . . . . . 126

Daytime Warm-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Optimal Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Night Purge (Night Economizing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Unoccupied Humidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Unoccupied Dehumidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Timed Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

General Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Best Practice for Commissioning: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Air Handler Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Commissioning the Communications Link . . . . . . . . . . . . . . . . . . . . . . . . . . 141

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Preliminary Checkout for LonTalk Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Finding a Short . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Finding an Open Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Preliminary Checkout for BACnet Communication Links . . . . . . . . . . . . . . 144

Auto-commission the Tracer VV550/551 and UC400 Controllers . . . . . . . . 149

Things to Consider Before Auto-commissioning . . . . . . . . . . . . . . . . . . . . . 150

Auto-commissioning Individual VAV Boxes with the Service Tools . . . . . 150

Auto-commissioning All VAV Boxes with Tracer SC . . . . . . . . . . . . . . . . . . 152

Interpreting the Auto-commissioning Report . . . . . . . . . . . . . . . . . . . . . . . . 155

Perform Air and Water Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Duct Static Pressure Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Static Pressure Sensor Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Setup Instructions for a Variable Volume Air Handler . . . . . . . . . . . . . . . . . 157

Setup Instructions for an MP580/581 Air Handler . . . . . . . . . . . . . . . . . . . . . 158

Tracer SC VAS Duct Static Pressure Optimization Setup . . . . . . . . . . . . . . 158

Ventilation Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Zone Level Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

System Level Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

Ventilation Ratio Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

Default Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Ventilation Optimization Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Ventilation Optimization Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Special Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Dedicated Ventilation Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Flow Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Auto-commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Manual Output Testing for VV550/551 Controllers . . . . . . . . . . . . . . . . . . . . 193

Manual Output Testing for UC400 Controllers . . . . . . . . . . . . . . . . . . . . . . . 195

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Sequences of Operation for Standard Operating Modes . . . . . . . . . . . . . . 196

General Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Optimal Start (Cooling Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

Optimal Start (Heating Mode)(Central Heat Used/Local Heat Not Used or Not Present) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Optimal Start (Heating Mode)(Local Heat with a Central Fan) . . . . . . . . . . 205

Humidity Pull-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

BAS-APG007-EN, 12/15/2009 5

Normal Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

Optimal Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

Unoccupied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Unoccupied Heating/Cooling—Cooling Mode . . . . . . . . . . . . . . . . . . . . . . . 216

Unoccupied Heating/Cooling—Heating Mode with Central Heat . . . . . . . . 219

Unoccupied Heating/Cooling—Heating Mode with Local Heat and a Central Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Unoccupied Heating/Cooling—Heating Mode with Local Heat and No Central Fan for Night Heat . . . . . . . . . . . . . . . . . . . . . 226

Night Purge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

Unoccupied Humidify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

Unoccupied Dehumidify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Timed Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

Communications Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

Isolating Problem VAV Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

Appendix A: Controller Flow Settings Worksheet . . . . . . . . . . . . . . . . . . 239

Appendix B: Tracer SC Mapping to MP580/581 Network Variable Inputs (nvi) and Profile Associations . . . . . . . . 241

Appendix C: Member Occupancy Response to Area and VAS Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242

Appendix D: Area and VAS Rank Arbitration for Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

Appendix E: Equipment Response to Operating Modes . . . . . . . . . . . . 245

Appendix F: Tracer SC Priority Levels and Assigned Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246

Appendix G: Trane Equipment Response to Optimal Start Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

Appendix H: Common Tracer SC Enumerations . . . . . . . . . . . . . . . . . . . . 249

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

©2009 Trane. All Rights Reserved. 6 PROPRIETARY INFORMATION OF TRANE. BAS-APG007-EN, 12/15/2009


Introduction

What is VAS?

The Variable-Air-Volume Air System (VAS), available in Tracer SC, permits you to control and coordinate air handlers and VAV boxes. The Tracer SC VAS includes valuable tools to help manage tasks that were previously problematic and time consuming, such as:

• Coordinating AHU and VAV box operation

• Commissioning VAV boxes

• Scheduling common spaces

• Optimizing ventilation

• Optimizing duct static pressure

Objectives

This guide presents a process to efficiently implement a basic, single-duct VAV air system. Following this recommended process should allow you to design and install a VAV air system that is easy to set up, works well from the outset, and requires minimal adjustment later.

Note: Because this applications guide focuses on standardizing and simplifying the process, it does not address Hybrid VAV systems such as dual duct, loop duct, and changeover bypass, which require customization.

With the instructions provided in this guide, you should know or be able to find out:

• What to think about when designing a project

• How best to install the equipment

• The most efficient way to set up the equipment and configure the VAV air system

• Best practices for configuring an MP580/581 using the DAC profile

• How to set up the standard functions for a VAV air system (Unoccupied Heating/Cooling, Optimal Start, etc.)

• The best way to commission a project

• How to optimize the VAV air system and implement special applications

• How best to maintain the equipment and the VAV air system

Overall Recommended Process

For best results, follow this recommended process:

1. Install, configure, and commission a basic system and make sure that it functions fully as expected. This provides a solid fall-back point you can use if you run into any issues during optimization (step 2).

2. Optimize and enhance the basic system, adding more complex strategies as needed to improve performance and achieve your goals.

By completing these steps in order, you may find it easier to isolate problems if they arise.

Best Practices

The best practices in this manual are interrelated and build on each other. They will help you save time and reduce cost. They are interspersed throughout the manual in colored boxes with a best practice star in the margin (as shown below). It is important to follow these best practices at each phase of the project to help ensure success in later phases.

This is a best practice box. They are located throughout the applications guide to call attention to important information and highlight best practices.Best

Practice



Introduction

Who Does What and When?

Figure 1 shows which people make decisions or perform tasks relating directly to the VAS system, and when those tasks and decisions occur. This illustration is repeated at the beginning of each section, with the appropriate step in the cycle highlighted. The project life-cycle shown in Figure 1 is reflected in the structure of this applications guide.

Some Assumptions About the Reader

To plan for, create, and maintain a VAV air system in a Tracer SC facility, you must understand the following:

• The nine different types of points they’ll find in the system:

– Analog, binary, and multi-state outputs

– Analog, binary, and multi-state inputs

– Analog, binary, and multi-state values

• How to use the Tracer TU and Rover service tools

• How to program TGP2

• The concept of a priority array

• How to accomplish simple and advanced overrides

• How to use referencers

For specific information on these concepts and tasks, refer to the Tracer SC online help or complete the Tracer SC Air Systems class through the Trane College of Automation.

Figure 1. Project life-cycle and responsibilities

Pipefitter - Mechanical ContractorElectrician - Power

Electrician - ControlsBAS Technician, Verification/Equipment Setup

Install

Control System Design Engineer

Order has been placed

BAS Technician(s)BAS Technician(s)

Air/Water Balance Contractor

Building Operator

BAS Technician

Program

Commission

Operate

Optimize

Design

Service Technician

Maintain



VAV Air System Components

VAV air systems are unique to the buildings they service. Some are complex, using dual duct, loop duct, and changeover bypass configurations that require special treatment at every phase of implementation. However, most VAV air systems are single-duct configurations composed of an air handler, ductwork, VAV boxes, and diffusers (refer to Figure 2). This guide focuses on these basic VAV air systems.

Although some installations utilize more specialized applications (such as ventilation optimization, or duct static pressure optimization) most are just extensions of the basic VAV air system.

Air Handling Unit (AHU)

The primary function of the AHU is to supply cold or hot air to the system depending on the configuration of the unit and the requirements within the system at any given time.

The AHU always has a cooling source—either a chilled water (CW) coil or a direct expansion (DX) coil, and it may also have the option to use outdoor air for cooling (economizing).

The AHU typically has a source of outdoor air for ventilation purposes. It may also have a heat source used to temper the primary air and/or to provide additional heat for Morning Warm-up and

Figure 2. Single-duct VAV air system

DuctworkAHU

VAV boxes

Diffusers (not shown)

(Each VAV box may have multiple diffusers)




Unoccupied Heating. Heating options include gas (staged or modulating), hydronic (hot water or steam), or electric (staged or modulating).

A VAV AHU typically has a variable speed supply fan controlled by a variable frequency drive (VFD) to maintain static pressure in the ductwork. The AHU may also have exhaust or return air fans installed, which are not discussed in this applications guide.

Ductwork

Ductwork provides the airflow path for a VAV air system connecting the AHU to the VAV boxes and diffusers.

VAV boxes

VAV boxes (also referred to as VAV terminal units) contain an airflow damper, an airflow sensor, a fan (optional), and a heat source (optional). There are four basic types of VAV boxes: Shutoff, VAV box with reheat, VAV box with parallel fan, VAV with series fan (refer to Figure 3). A project may use only one type of VAV box throughout the installation; however, it is more common that a variety of VAV boxes are installed and used for specific purposes depending on their location in the building or within each zone.

Figure 3. VAV boxes: how they work and how they are used

Shutoff VAV How it works

Shutoff VAV boxes control the flow of supply air to the space to maintain a zone temperature at setpoint. Typically, each VAV box is wired to a temperature sensor in the zone.

Common applications

They are typically used in cooling-only applications that do not require heat during occupied hours.

VAV with Reheat How it works

VAV boxes with reheat are similar to a shutoff box, with the addition of a heat source. The heat source is typically located at the box's outlet and can be hot water or electric. The air damper inside the VAV box typically has an adjustable minimum flow setting to ensure sufficient airflow to a zone in the heating operation mode.

Common applications

They are typically used when system-first cost is a primary consideration and heat is required during occupied hours.

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Diffusers

Diffusers are typically located in the ceiling, above the occupied spaces, and downstream (in the airflow path) of the VAV boxes.

Parallel fan-powered VAV How it works

A parallel fan-powered VAV has an air damper similar to a shutoff box. In addition, it has a fan, backdraft damper, and a heat source. When reheat is not required, the fan is off and a back-draft damper is closed to prevent cool air from entering the return plenum. When reheat is required:

• First stage—the fan pulls warm plenum air into the VAV box through the backdraft damper where it mixes with cool primary air

• Second stage—electric or hot water coil placed at the outlet of the VAV box

Common applications

Using warm plenum air as the first stage of heat in the VAV box may significantly reduce operating costs over electric or hot water reheat alone.

Series fan-powered VAV How it works

The series fan operates continuously, while the damper modulates to vary the ratio of warm plenum air to cool supply air. The result is a constant volume of variable temperature air flowing into the space. Additional reheat may also be available from a heating coil located at the VAV box outlet.

Common applications

Series fan-powered VAV boxes are often selected by designers who wish to take advantage of the unique characteristics of constant air delivery to the zone, while still benefiting from the energy savings associated with a VAV system. Series fan-powered VAV boxes may be used throughout the entire building or they may be applied selectively in areas such as restrooms, entrance ways, and hallways, where it is desirable to maintain a constant airflow regardless of load.

Figure 3. VAV boxes: how they work and how they are used (continued)

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Building Automation System (BAS)

A BAS is the control system used in a building or group of buildings to coordinate operation of the HVAC equipment, monitor alarms, trend data, and allow technicians and building owners to manage schedules, define spaces, and control space temperature. The Tracer SC BAS is typically composed of:

• Tracer SC—The Tracer™ SC system controller acts as the central coordinator for all individual equipment devices on a Tracer building automation system. The Web-based interface of the Tracer SC system controller provides an easy and convenient way for building operators to access their building automation system. Access is available from any personal computer with access to the Tracer SC network, even from remote locations.

• Rover service tool—The Rover™ service tool is used to configure, monitor, and test Trane unit-level controllers that communicate using the LonTalk protocol.

• Tracer TU service tool—The Tracer TU service tool is used to configure, monitor, test, and program the Trane system and unit-level controllers using BACnet, USB, and Ethernet. It is also used to program TGP2 in Tracer SC.

Although chillers and boilers are often controlled by a Tracer SC BAS, they are usually not considered part of a VAV air system, and they are not discussed in this applications guide.

Tracer SC Variable-Air-Volume Air System Benefits

The Tracer SC Scheduling, Area, and VAS application software coordinates air-handling units and VAV boxes within a building and provides:

• Efficient space comfort control

• Cost-effective ventilation control

• Cost-effective duct static pressure control

• The ability to schedule Start, Stop, Optimal Start, Optimal Stop, Humidity Pulldown, and Night Economize actions for each Area of the building

• Applications to help you minimize energy costs (humidity control, economizing decisions, Optimal Start and Optimal Stop, etc.)

• Useful information about the occupant spaces and the air handling equipment (application status pages and standard reports)

• A means by which a building owner can create, manage, and bill multiple tenants

• Easy setup, commissioning, and troubleshooting tools (Rover service tool, Tracer TU service tool, VAS Auto-commissioning, etc.)



Design Considerations

This section provides information to consider while designing a project that contains a VAV air system. Choosing the right equipment is the most important element in designing a VAV air system. Choosing the wrong equipment can add substantial cost and setup time to the project.

Air Handling Unit (AHU)

Consider the following information when selecting an air handler for the project:

Choose an AHU that can sense and control the duct static pressure. A single static pressure sensor is located at the fan outlet. A static pressure controller adjusts the variable frequency drive to maintain the duct static pressure at a fixed (design) or variable (optimized) setpoint.

Choose an AHU that can control its discharge air temperature while cooling. Air handlers in a Tracer SC VAS should be able to control their discharge air temperature while cooling. Trane AHUs do this, although some (IntelliPak™ and ReliaTel™) do not control their discharge air temperature during certain heating scenarios. If using non-Trane air handlers, make sure they can control the discharge air temperature while cooling.

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Use a variable setpoint that is based on the position of the VAV terminal dampers (refer to “Duct Static Pressure Optimization,” p. 157). Best

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Climate Changers need to be ordered with an MP580 controller (refer to Table 1), which is a native LonTalk controller. Order IntelliPaks, Commercial Self-Contained, and Commercial Voyagers with a LonTalk Communication Interface (LCI) card, not a Tracer Communication Interface (TCI).

*Scheduled for 2010 release.**UC600 is scheduled for 2011 release.

Line voltage power is required for the Tracer MP581. If possible, the electrical contractor should bring line voltage power to the AHU controller to power the control transformer. However, if that is not possible, allocate enough time and material to run the line voltage power to the controller. Work with the consulting engineer to ensure that the electrical prints show power coming to the AHU controller. Know the voltage of this power source to order the correct step-down (to 24 Vac) transformer with the Tracer MP581.

Do not wire critical inputs and outputs to EX2 expansion modules. Instead, wire them directly to the MP580/581 controller. If communications fail to the EX2, the control fails to the last state. Use EX2s for ancillary points.

Do not hard-wire a space temperature sensor to the air handler. In comm loss situations, the AHU goes into Occupied mode 15 minutes after it loses communication. If the AHU has a heat source, and morning and/or daytime warm-up are enabled, the AHU could go into a warm-up cycle as needed. If the VAV boxes downstream cannot communicate with the AHU to see that it is going into a constant volume mode of operation (Max Heat), the VAV box air dampers will not drive to max to accommodate the increased airflow. This could result in damage to the duct system.

Table 1. Equipment and controller pairings

Equipment Controller

M-series Climate Changer Tracer MP580

T-series Climate Changer Tracer MP580

Custom Climate Changer Tracer MP580

Commercial Voyager RTUs LCI-R, BCI-R*

IntelliPak rooftop units (RTUs) Commercial Self-contained units

LCI-I, BCI-I

100% outdoor air unit Tracer MP581, UC400, UC600**

Non-Trane air handler Tracer MP581, UC400, UC600**

Limit each AHU controller to controlling only one AHU

This may only apply to the MP580/EX2. Reasons to avoid using the MP580/EX2 to control multiple AHUs:

• It might be a violation to the job specification.

• If the MP580 fails or is being serviced, 2 or more AHUs are shut down, instead of one.

• Wiring costs increase if the AHUs are not in the same room.

• There is an increased chance of error during configuration and TGP programming (looking at the wrong input or controlling the wrong output).

• Tracer SC uses profile variables to control MP580/581.

• Tracer SC applications to not support more than one AHU per controller.

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Are airflow measurement stations required? If the design engineer has specified ventilation airflow requirements for the VAV boxes, an airflow measurement station at the AHU may be necessary to measure and control the amount of outdoor air being brought into the system.

• Order Traq™ dampers with the IntelliPak and Climate Changer.

Note: If using a Climate Changer for a 100% outdoor air unit in a dedicated ventilation system, Traq dampers may not be necessary.

• Traq dampers on Self-Contained units are only offered on 20 to 80 ton water-cooled units with air-side economizers. Instead of using Traq dampers to measure the amount of outdoor air delivered to your CSC (or if you have a water-side economizer with your CSC), use a VAV box (if the building design allows for it). The VAV box in this case is part of a dedicated ventilation system (refer to “Dedicated Ventilation Systems,” p. 181).

Note: Depending on the amount of ventilation air required, or if the space the CSC serves has more than one Area, more than one VAV box may be needed.

• Although Traq dampers are not offered on the VAV Commercial Voyager, the unit has a function called OA CFM Compensation Control, which modifies the OA damper minimum position based on the reported unit airflow.

Note: OA Flow Compensation control is NOT compatible with ventilation optimization. Refer to the guide on ReliaTel Microprocessor Controls, RT-SVD03C-EN, for additional details on OA CFM Compensation.

When required to report AHU supply fan airflow, a suitable substitution may be the summation of all VAV box airflows.

VAV Boxes

Consider the following information when selecting VAV boxes for the project:

Order a zone sensor with the VAV box. •

• If it is necessary to initiate or cancel Timed Override from a zone sensor, order a sensor with an ON button or ON/CANCEL buttons.

• If a communication stub is wired to the space sensor, order a space sensor with a communication jack.

• If using wireless zone sensors, order the VAV box with a factory-mounted wireless receiver to avoid field installation

Note: Do not order a zone sensor for VAV boxes that are configured for Flow Tracking or Ventilation Flow Control because they do not use the sensor. Refer to “Special Applications,” p. 181 for more information.

Order a LonTalk DDC controller (Tracer VV550/551) or UC400 controller with the VAV

box. The Tracer SC VAS has several features designed around Trane controllers. These features include ventilation optimization, CO2 demand-controlled ventilation, and auto-commissioning, which significantly enhances the VAV air system.

Order an auxiliary temperature sensor with any fan-powered VAV box (VSxx, VPxx) or

any single-duct VAV box with reheat (VCWF, VCEF). (Specify that it be installed in the

discharge air stream). This sensor is crucial for monitoring performance and for troubleshooting. It is installed by the controls electrician (so budget accordingly) in the discharge air stream of the VAV box and is used for the controller auto-commissioning sequence.

Note: When a VAV box is used only for ventilation (as is found in a dedicated ventilation system, for example), in northern climates, order electric or hot water reheat with the VAV box if the AHU supplying that outdoor air has limited or no reheat capabilities. An auxiliary temperature sensor is required for VAV boxes that have reheat and are configured for Ventilation Flow Control.




Is an occupancy sensor necessary? If the sequence of operation calls for occupied stand-by operation (using alternate temperature and airflow setpoints during occupied hours if the zone is vacant), purchase an occupancy sensor (dry contacts only) for that VAV box. The controls electrician installs this sensor, so budget accordingly.

Is CO2 level monitoring required? When using Tracer UC400 controllers on VAV boxes, the controller has a CO2 sensor terminal on the board; however, the Tracer VV550/551 does not support a hardwired input for CO2; only communicated values are accepted. If it is necessary to monitor or control the amount of CO2 in the space served by the VAV box (a CO2-based demand-controlled ventilation zone application), purchase a CO2 sensor. The controls electrician installs this sensor, so budget accordingly.

Do not use hot water heat in Ventilation Flow Control (VFC) boxes on a dedicated

ventilation VAS. There is no freeze protection for VAV boxes with hot water heat when they are used as VFC boxes in a dedicated ventilation system. Instead, use shutoff VAV boxes or electric reheat VAV boxes as the VFC box. Refer to “Dedicated Ventilation Systems,” p. 181 for more information.

For single-duct VAV terminal units (VCCF, VCWF). Often, the customer’s design engineer or architect will not bring 120 Vac power to the VAV box if the box does not have a fan (series or parallel) or electric reheat. The cost to bring 24 Vac to the VAV boxes by centrally mounting a transformer and then running 24 Vac to each VAV box after the fact will be much more expensive if the design engineer does not specify 120 Vac power initially. Be sure to incorporate the appropriate costs in the estimate for supplying power to VAV boxes without fans or reheat that still require power.

Important: Do not order a factory-mounted transformer with single-duct terminal units (VCCF, VCWF). If the factory-mounted transformer is ordered, it may not get used because it is too expensive to have the electrical contractor bring 120 Vac to the box (the 120 Vac would likely need to be in conduit).

The Trane project engineer should specify the airflow setpoints for each VAV box.

There are many airflow setpoints to address, such as heating and cooling airflow setpoints for minimum, maximum, and standby airflow. A flow settings worksheet is included in Appendix A of this guide to assist with this task (refer to “Appendix A: Controller Flow Settings Worksheet,” p. 239). Use the schedule of VAV boxes obtained from the customer’s engineer or architect to

For VV550/551 only.

Buy a non-communicating sensor. Wire a non-communicating sensor to an MP580 (main board or EX2), then create a TGP2 program in the Tracer SC that reads the CO2 sensor value from the MP580/581 and writes the value to the VAV box Space CO2 Concentration BAS point. The sensor value must represent CO2 in parts per million (ppm). The voltage or current input to the MP580/EX2 must have the appropriate multiplier and offset applied to it to represent CO2 in ppm.

On systems that require CO2-based demand controlled ventilation, avoid having to provide a CO2 sensor in every zone. Work with the design engineer so CO2 sensors only get specified in those zones (conference rooms, for example) that can be densely occupied but experience widely varying patterns of occupancy.

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If power is needed at the box, have the electrical contractor use a 100 VA Class 2 120/24 Vac transformer and daisy chain the 24 Vac to a maximum of three boxes. If there is a VAV box nearby with a fan or electric heat it may also be possible to tap power from its factory-mounted 50 VA 120/24 Vac transformer.

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specify the flow settings for each VAV box on the worksheet. The installing technician and BAS technician will use this worksheet to set up the VV550/551 controllers and Tracer SC.

Considerations related to the VV551 Retrofit Kit

Reversing the action of the damper actuator. Normally, the actuator turns the jack shaft in a counter-clockwise rotation to open the damper. If the jack shaft protrudes from the side of the box that requires a clock-wise rotation to open the damper, the actuator will turn the damper the wrong way. Instead of opening, the damper hits a stop that prevents it from moving. To reverse the action of the actuator, do one of the following:

• Reverse the two wires connected to the actuator. Belimo actuators have a retrofit kit that permits you to reverse the terminals. For Trane actuators, you must cut and splice the wires.

• Change the software configuration for the VV551 using the Rover service tool (Configuration > Other). This requires Rover service tool version 7.0, and VV550/551 software version 1.04.0004 or later.

Power. Find out if there is a source of power (24 Vac) already at the VAV box on which you are installing the retrofit kit, and provide it if necessary. Typically, when retrofitting pneumatic boxes, except for rare DDC boxes, there will not be power at the box

Tracer SC Sizing

The Tracer SC can support up to 120 total devices, including any combination of devices on the two BACnet MSTP links and the LonTalk link. Currently the Tracer SC can support up to 30 devices on each of the BACnet MSTP links and 120 devices on the LonTalk link. LonTalk links with more than 60 devices require a repeater, which may include devices other than those associated with the VAV control system.

Note: If there are MP580/581 devices on the LonTalk link, the total number of devices cannot exceed 70 (MP580/581s + LonTalk devices).

LonTalk Wiring Guidelines

For detailed information on wiring unit controllers in a Tracer SC system, refer to the most recent version of BAS-SVN03-EN, Unit Controller Wiring for the Tracer SC System Controller.

Refer to “Installation,” p. 26 for more detailed information on communication, power, and signal wiring.

If you have to bring power to the box, have the electrical contractor use a 100 VA Class 2 120/24 Vac transformer and daisy chain the 24 Vac to a maximum of three boxes. If there is a VAV box nearby with a fan or electric heat it may also be possible to tap power from its factory-mounted 50 VA 120/24 Vac transformer.

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Sequence of Operation

This section contains text that can be copied and pasted into submittals (or guide specifications). Use the text as is to ensure there will be no question that Trane equipment will be able to function according to the requirements. Keep in mind that submittals are for equipment such as AHUs and VAV boxes and not control systems. The goal is that the person reading the submittal has an increased understanding of Trane equipment and how it operates.

How VAV Boxes Work

The following sections describe the operation of single-duct, parallel fan powered, and series fan powered Variable Air Volume (VAV) terminal units with Direct Digital Controls (DDC). In each case, VAV terminal units can support the following control schemes:

Space temperature control (with or without a fan, with or without reheat)

• Occupied with cold or hot primary air

• Unoccupied with cold or hot primary air

Flow tracking (without fan, without reheat)



Ventilation flow control (without fan, with or without local reheat)



Note: Cold primary air is primary air that is colder than the VAV box configured auto changeover setpoint, minus 10°F (°C). Hot primary air is primary air that is hotter then the VAV box configured auto changeover setpoint.

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Single-Duct VAV Terminal Units

Single-Duct VAV Terminals, Cooling Only

Space Temperature Control

• Occupied, primary air is cold

As the space temperature rises above the occupied cooling setpoint, the VAV terminal unit shall modulate open to its maximum cfm. As the space temperature falls below the occupied cooling setpoint, the unit shall modulate closed to its minimum cfm.

• Occupied, primary air is hot

As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm. As the space temperature rises above the occupied heating setpoint, the unit shall modulate closed to its minimum heating cfm. If the unit knows the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to it maximum heating cfm.

• Unoccupied, primary air is hot

As the space temperature falls below the unoccupied heating setpoint, the unit shall open to provide maximum heating cfm. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve. If the unit knows the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm.

• Unoccupied, primary air is cold

On a rise in space temperature above the unoccupied cooling setpoint, the VAV terminal unit shall open to provide maximum cfm. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve.

Flow Tracking

• Occupied and Unoccupied operating modes are not supported. Flow tracking VAVs always follow the communicated airflow setpoint plus the configured offset.

Ventilation Flow Control

• Occupied, primary air is cold or hot

Control the airflow to the communicated ventilation setpoint.

• Unoccupied, primary air is cold or hot

Air valve is closed.

Single-Duct VAV Terminals with Reheat



As the space temperature rises above the cooling setpoint, the VAV terminal unit shall modulate open to its maximum cooling cfm setpoint. As the space temperature falls below the cooling setpoint, the unit shall modulate to its minimum cooling cfm setpoint. As the space temperature falls below the heating setpoint, the unit shall turn on the reheat and modulate to its minimum local heating cfm. Refer to the reheat section below for more reheat details. As the space temperature rises above the heating setpoint, the reheat is turned off and the air valve modulates closed to its minimum cooling cfm.





As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm and bring on the reheat. If the primary air is hotter than the configured reheat enable setpoint the reheat shall be turned off. As the space temperature rises above the occupied heating setpoint, the unit shall modulate closed to its minimum heating cfm. The reheat shall be turned off. If the unit knows the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to its maximum heating cfm.


As the space temperature falls below the unoccupied heating setpoint, the unit shall open to provide maximum heating cfm and turn on the reheat at 100%. If the primary air is hotter than the configured reheat enable setpoint the reheat shall be turned off. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve and turn off the reheat. If the unit knows the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm.


On a rise in space temperature above the unoccupied cooling setpoint, the VAV terminal unit shall open to its maximum cfm. The reheat shall be off. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve. The reheat shall be off. As the space temperature continues to fall below the unoccupied heating setpoint, the unit shall open to its configured local heating minimum cfm and turn on the reheat at 100%. As the space temperature rises above the unoccupied heat setpoint, the reheat turns off and the air valve closes.

Flow Tracking (does not support reheat)

Ventilation Flow Control (with reheat)

• Occupied, primary air is cold or hot

Control the airflow to the communicated ventilation setpoint. Control the reheat to keep the discharge air temperature at the discharge air temperature setpoint over a 30 minute average.

• Unoccupied, primary air is cold or hot

Air valve is closed and the reheat is off.

Reheat Options

Choose the appropriate reheat paragraph for the kind of reheat present in the box.

• Staged Electric—Stage on up to 3 stages of electric heat with a 1 degree interval per stage as the space temperature falls below the heat setpoint. Stage off the electric heat stages as the space temperature rises 0.5 degrees above the turn on point.

• Pulse Width Modulation (PWM)—The first, second, and third stage of heating shall be energized based on time and temperature deviation below the heat setpoint. The heat stages will be brought on in order, and duty cycled one at a time, to meet the desired heating capacity. The stages will be duty cycled on a 3 minute period. Desired heating capacity will be distributed equally among all heat stages that are present.

• Two-Position Hot Water—Open the two-position valve as the space temperature falls below heating setpoint. Close the valve as the space temperature rises more than 0.5 degrees above the heating setpoint.

• Proportional Hot Water—The position of the hot water valve is based on time and temperature deviation below the heat setpoint.




Parallel Fan-Powered Terminal Units

Parallel Fan-Powered VAV Box with No Reheat



Intermittent Fan Control—On a rise in space temperature above the cooling setpoint, the VAV terminal unit shall modulate open to its maximum cfm. As the space temperature falls below the cooling setpoint, the unit shall modulate closed to its minimum cfm. Upon a continued drop in temperature or unit cfm, the parallel fan shall be energized. As the space temperature rises or the unit cfm rises, the parallel fan will be turned off.


As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm. The parallel fan shall be off. As the space temperature rises above the occupied heating setpoint, the unit shall modulate closed to its minimum heating cfm. The parallel fan shall be turned off. If the unit knows the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to its maximum heating cfm.


As the space temperature falls below the unoccupied heating setpoint the unit shall open to its maximum heating cfm and the parallel fan stays off. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve and the parallel fan stays off. If the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm and the parallel fan shall stay off.


As the space temperature rises above the unoccupied cooling setpoint, the VAV terminal unit shall open the air valve to its maximum cfm. The parallel fan shall be off. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve. The parallel fan shall be off.

Flow Tracking (does not support parallel fan)

Ventilation Flow Control (does not support parallel fan)

Parallel Fan-Powered VAV Box with Reheat



Intermittent Fan Control—On a rise in space temperature above the cooling setpoint, the VAV terminal unit shall modulate open to its maximum cfm. As the space temperature falls below the cooling setpoint, the unit shall modulate to its minimum cooling cfm. Upon a continued drop in temperature or unit cfm, the parallel fan shall be energized. As the space temperature falls below the heating setpoint, the unit shall turn on the reheat and modulate open to its minimum local heating cfm. Refer to the reheat section for more reheat details. As the space temperature rises above the heating setpoint, the reheat is turned off and the air valve modulates closed to its minimum cfm. As the space temperature continues to rise or the unit cfm rises, the parallel fan will be turned off.


As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm. The parallel fan shall turn on when the reheat turns on. If the primary air is hotter than the configured Reheat Enable Setpoint, the reheat and the parallel fan shall be turned off. As the space temperature rises above the occupied heating




setpoint, the unit shall modulate closed to its minimum heating cfm. The parallel fan shall be turned off. The reheat shall be turned off. If the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to its maximum heating cfm. The parallel fan and the reheat are off.


Intermittent Fan Control—As the space temperature falls below the unoccupied heating setpoint the unit shall open to its maximum heating cfm. The parallel fan shall turn on when the reheat turns on. If the primary air is hotter than the configured Reheat Enable Setpoint, the reheat and the parallel fan shall be turned off. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve. If the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm, the parallel fan and the reheat are off.


On a rise in space temperature above the unoccupied cooling setpoint, the VAV terminal unit shall open to its maximum cfm and the parallel fan is turned off. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve. As the space temperature continues to fall below the unoccupied heating setpoint, the unit shall turn on the parallel fan and the heat at 100%. The air valve stays closed. As the space temperature rises above the unoccupied heat setpoint, the parallel fan and the reheat turn off.

Flow Tracking (does not support reheat or parallel fan)

Ventilation Flow Control (does not support parallel fan)

Reheat Options




• Two-Position Hot Water—Open the two-position valve as the space temperature falls below heating setpoint. Close the valve as the space temperature rises more than 0.5 degrees above the heating setpoint.


Series Fan-Powered Terminal Units

Series Fan-Powered VAV Box with No Reheat



Continuous Fan Control—The series fan is always on in Occupied mode. On a rise in space temperature above the cooling setpoint, the VAV terminal unit shall modulate open to its maximum cfm. As the space temperature falls below the cooling setpoint, the unit shall modulate closed to its minimum cfm.





Continuous Fan Control—The series fan is always on in Occupied mode. As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm. As the space temperature rises above the occupied heating setpoint, the unit shall modulate closed to its minimum heating cfm. If the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to its maximum heating cfm and the series fan is on.


Intermittent Fan Control—As the space temperature falls below the unoccupied heating setpoint, the unit shall open to its maximum heating cfm and the series fan is on. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve and turn off the series fan. If the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm and the series fan is on.


Intermittent Fan Control—As the space temperature rises above the unoccupied cooling setpoint, the unit shall open to its maximum cfm and the series fan is on. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve and turn off the series fan.

Flow Tracking (does not support series fan)

Ventilation Flow Control (does not support series fan)

Series Fan-Powered VAV Box with Reheat



Continuous Fan Control—The series fan is always on in Occupied mode. On a rise in space temperature above the cooling setpoint, the VAV terminal unit shall modulate to its maximum cfm. As the space temperature falls below the cooling setpoint, the unit shall modulate to its minimum cooling cfm. As the space temperature falls below the heating setpoint, the unit shall turn on the reheat and modulate open to its minimum local heating cfm. Refer to the reheat section for more reheat details. As the space temperature rises above the heating setpoint, the reheat is turned off and the air valve modulates closed to its minimum cfm.


Continuous Fan Control—The series fan is always on in Occupied mode. As the space temperature falls below the occupied heating setpoint, the VAV terminal unit shall modulate open to its maximum heating cfm. The reheat shall be turned on. If the primary air temperature is hotter than the reheat enable setpoint, the reheat shall be turned off. As the space temperature rises above the occupied heating setpoint, the unit shall modulate closed to its minimum heating cfm. The reheat shall be turned off. If the air handler is running in the constant volume mode during occupied heating, the unit shall open its air valve to its maximum heating cfm, the series fan shall be on and the reheat shall be off.


Intermittent Fan Control—As the space temperature falls below the unoccupied heating setpoint the unit shall open to its maximum heating cfm and the series fan is turned on. As the space temperature rises above the unoccupied heating setpoint, the unit shall close the air valve and turn off the series fan. If the air handler is running in the constant volume mode during unoccupied heating, the unit shall open its air valve to its maximum heating cfm, the series fan shall be on and the reheat shall be off.





Intermittent Fan Control—On a rise in space temperature above the unoccupied cooling setpoint, the VAV terminal unit shall open to its maximum cfm and the series fan is turned on. As the space temperature falls below the unoccupied cooling setpoint, the unit shall close the air valve and turn off the series fan. As the space temperature continues to fall below the unoccupied heating setpoint, the unit shall turn on the series fan and the heat at 100%. The air valve stays closed. As the space temperature rises above the unoccupied heat setpoint, the fan and the reheat turn off.

Flow Tracking (does not support series fan or reheat)

Ventilation Flow Control (does not support series fan)

Reheat Options




• Two-Position Hot Water—Open the two-position valve as the space temperature falls below the heating setpoint. Close the valve as the space temperature rises more than 0.5 degrees above the heating setpoint.


How the Air Handler Works

The following sections describe the operation of an air handler with discharge air control. The air handler described can perform the following functions:

• Supply fan control

• Heating control (hot water, electric heat, or gas)

• Mechanical cooling control (cold water or DX)

• Ventilation control (outdoor air)

• Economizing control (cool outdoor air)

Variable Volume Air Handling Units (VAV AHUs)

Occupied

The VAV AHUs shall modulate the air handler supply fan speed to control the duct static pressure to the duct static pressure setpoint. If the VAV AHU does not control the duct static pressure, it shall report Max Heat.

The VAV AHU shall open the outdoor air damper to the minimum position to ventilate the space.

The VAV AHU shall control the discharge air temperature (DAT) to the discharge air cooling setpoint. As the DAT rises above the setpoint, the VAV AHU shall use both economizing (if possible) and mechanical cooling to control the DAT to the setpoint. As the VAV AHU falls below the setpoint, the VAV AHU shall reduce cooling and economizing and use heating (if necessary) to control the DAT to the setpoint.




If the air handler has heat, it shall support daytime warm-up. As the space temperature falls below the daytime warm-up initiate setpoint, the VAV AHU shall control the DAT to the discharge air heating setpoint. As the space temperature rises above the daytime warm-up terminate setpoint, the VAV AHU shall control the DAT to the discharge air cooling setpoint.

If the air handler has heat, it shall support morning warm-up. On the transition from Unoccupied to Occupied, if the space temperature is below the morning warm-up initiate setpoint, the VAV AHU shall control the DAT to the discharge air heating setpoint. As the space temperature rises above the morning warm-up terminate setpoint, the VAV AHU shall control the DAT to the discharge air cooling setpoint.

Unoccupied

As the space temperature rises above the unoccupied cooling setpoint, the VAV AHU shall turn on the supply fan and use mechanical cooling and economizing, if possible, to control the discharge air temperature (DAT) to the discharge air cooling setpoint. The duct static pressure shall be controlled. As the space temperature falls below the unoccupied cooling setpoint, the VAV AHU shall turn off the supply fan and the mechanical cooling and close the outdoor air damper.

As the space temperature falls below the unoccupied heating setpoint, the VAV AHU shall turn on the supply fan and use heating to control the DAT to the discharge air heating setpoint. The duct static pressure shall be controlled. As the space temperature rises above the unoccupied heating setpoint, the VAV AHU shall turn off the supply fan and the heating.

If the VAV AHU does not control the duct static pressure, it shall report Max Heat.

How the System Works

Use the text below to include the special applications associated with Trane’s VAV Air System (VAS) capability.

Duct Pressure Setpoint Optimization

(Refer to: ANSI/ASHRAE/IESNA Standard 90.1-2004, Section 6.5.3.2.3)

If duct pressure optimization is enabled, the building automation system shall monitor the damper position of all VAV terminal units in each VAS object. A critical zone is found for each VAS object. The VAV terminal unit with the most open air valve is the critical zone for that VAS object. The frequency of this calculation is selected in the VAS editor.

When the critical zone is more open than the high limit, the duct pressure setpoint shall be recalculated based on the Reset Up Increment. The duct pressure setpoint is limited by the Maximum Value.

When the critical zone is less open than the low limit, the duct pressure setpoint shall be recalculated based on the Reset Down Increment. The duct pressure setpoint is limited by the Minimum Value.

Minimum Outdoor Air Control

Minimum Required Outdoor Airflow Setpoint

The AHU outdoor-air damper shall be controlled to deliver required outdoor airflow at all load conditions. The outdoor airflow setpoint shall be determined according to ASHRAE Standard 62-2001, Equation 6-1. The actual outdoor airflow shall be sensed at the outdoor air intake.

The BAS shall include a time-of-day schedule to indicate whether a zone is normally Occupied or Unoccupied. When the schedule indicates that the zone is normally Unoccupied, the required outdoor airflow for the zone shall be zero. When the schedule indicates that the zone is normally Occupied, the required outdoor airflow for the zone shall equal the design outdoor airflow (based on design occupancy), unless the zone is equipped with an occupancy sensor and/or a carbon dioxide (CO2) sensor.




• For those zones equipped with an occupancy sensor, the required outdoor airflow for the zone shall be continuously determined based on whether people are present or not. When the occupancy sensor indicates that people are present in the zone, the required outdoor airflow shall equal the design outdoor airflow. When the occupancy sensor indicates that no people are present in the zone, the required outdoor airflow shall equal the Occupied Standby outdoor airflow.

• For those zones equipped with a CO2 sensor, the required outdoor airflow for the zone shall be continuously calculated using the measured CO2 concentration as an indicator of the current per-person ventilation rate.

The required outdoor-air fraction shall be continuously calculated for each VAV terminal zone. Outdoor-air fraction is defined as the current required outdoor airflow for the zone divided by the current primary airflow to the zone.

The BAS shall regularly determine the highest zone outdoor-air fraction, sum the outdoor airflow requirements for all VAV zones, and sum the current primary airflows for all VAV zones to determine the total system primary airflow. This information shall be used in Equation 6-1 of ASHRAE Standard 62-2001 to calculate the minimum required outdoor airflow for the system. This minimum outdoor airflow setpoint shall be recalculated every 15 minutes (adjustable).



Installation

This section contains basic installation and connection guidelines. Detailed information is located in the ship-with documents that came with the devices. References to those documents are provided as appropriate.

VAV Box Connections

The following items are covered:

• Zone sensors

• Discharge air sensor

• Hot water valve

• Communication wiring

• Power considerations

Air Handler Connections

Static pressure sensor installation considerations.

Assumptions

When the following equipment is referred to in this section, these assumptions apply:

• The controller is factory-mounted on all VAV boxes.

• The air valve actuator is factory-mounted on all VAV boxes.

• Fan-powered VAV boxes have their fans mounted and wired at the factory.

• Electric heat in VAV boxes is installed and wired at the factory.

• There is 24 Vac or a single-point connection that provides 24 Vac.

Overview

Figure 4, p. 27 and Figure 5, p. 28 give a summary view of the devices that are typically wired to the VV550/551 and UC400 controllers in a VAV application and their terminations on the controllers. Following the figures are brief descriptions of the devices, how they are used, and, if applicable, best practices for connecting them. For detailed information on wiring specifications, terminations, and instructions, refer to the documents shipped with the devices.



Control System Des


n(s)

Balance Contractor

Building Operator

BAS Technician



sigggn Engineer

BAS Technician(s)BAS Technicianaa

AiAiAir/r/r/WaWaWateteterrr BBB

Service Technician

Install

ProgramProgram

Commission

Operate

Optimize

Design

Maintain



Installation

Figure 4. Typical connections for VV550/551 controllers.

AUX

Primary air temperature (Supply)orDischarge air temperature

GNDZONE GND SET

24VGND 24V

BI1

J8 J9 J10

J11

24VGND

COMM

TOOL

COMMCOMM

IN OUT

5 Heat Setpoint (HSP)4 SVS/Fan Mode (Mode)3 Setpoint2 Signal Common (Common)1 Zone Temperature (Zone Temp)

11 24 Vac/Vdc10 Ground

987 Comm –6 Comm +

Dry contactsonly

Heat 3 is defined as: Fans in series or parallel fan

powered VAV boxes Stage 3 local or remote

heat in no fan situations

AC-power wiring

24 Vac transformer

Air valve openclockwise)(counter

Air valve close(clockwise)

24 Vac

23456 1

HE

AT3

HE

AT2

HE

AT1

TB4_

1TB

4_2

TB3_

1TB

3_2

TB3_

3TB2_

3TB

2_4

TB2_

1TB

2_2

TB2_

5TB

2_6

TB3_

5

FLO

W

J2-3J2-2J2-1

ACTUATORJ1

Actuator

Hot Water Valve/Electric Heater

wiring

TB3_

6

TB1_

1

TB1_

2

Note:

Chassisground

Fan

On - Offwater valve

24Vac

J11 - Heat 3

J9 - Heat 1

J8 - 24V

Hot water - 2 position

Fan(if applicable)

Proportionalwater valve

24Vac

J11 - Heat 3

J9 - CLOSE

J8 - 24V

Hot water - Proportional

J10 - OPEN

Fan

Heaterstage

contactors24Vac

J11 - Heat 3

J9 - 1st Stage

J8 - 24V

Electric heater staged/Pulse width modulation (PWM)

J10 - 2nd Stage

(if applicable)(if applicable)

***

**

* Terminations on the zone sensor vary depending on whether it is digital or not. (refer to the installation sheets for specific terminations).

Zone Sensor



Installation

Figure 5. Typical connections for UC400 controllers.

BO4

IMC IMC

P 1 P 2

UC400

0

5

9

87

6

1

23

4

x1

0

5

9

87

6

1

23

4

x10

0

5

9

87

6

1

23

4

x100

ADDRESS

TRIAC

BO5 BO6 BO9A B B A

AO1BI4

AO2BI5

24Vac

24Vac

24Vac

BI1 BI2 BI3XFMR

AI5

+24Vdc

AI2AI1 AI3 AI4

BO7 BO8

TRIAC SUPPLY

CNCNOCNCNOCNCNO

RELAYSBO1 BO2 BO3

CONNECT AC POWER TO THE TRIAC SUPPLY TO POWER THE TRIACS

BO1 BO2 BO3 B07 B08 BO9BO4 BO5 BO6

SERVICE TOOL

LINK IMC

BI1: Occupancy Input

24VAC – 240VAC POWER SUPPLY

AI5: Aux Temp(Supply Air Temp)

AI4: Discharge Air Temp

AI2: Space Temp Setpoint

AI1: Space Temp

UI1: Relative Humidity

UI2: CO2

AI1 AI3 AI4AO1BI4

AO2BI5

AI2 AI5

P 1 P 2

Kavlico Pressure Sensor

VAV Application:Fan Type: Series or ParallelFan Motor: ECM or Standard (see footnote)

Reheat Type: Electric Reheat

BO1: ECM FanSee footnote

BO5: Stage 3 Heat

BO6: Stage 2 Heat

BO7: Stage 1 Heat

BO4: Fan On/OffSee footnote

Footnote: If using a standard motorized fan, connect to the BO4 terminal and not BO1. If using an ECM motorized fan, connect to BO1 and not BO4. For an ECM application, BO1will be slaved to BO4 via software.

RXTX

LINK IMC

SERVICE

Air Valve8=Close, 9=Open

Comm. inComm. out

Zone sensor comm

120

Vac

24 V

ac

UI1 UI2

UI1 UI2



Installation

Zone Sensors

A zone sensor measures the temperature of the space served by the VAV box. A zone sensor with an optional space setpoint input measures the temperature of the space and allows a user to generate a request for a different setpoint at the sensor. Both sensor types have the same wire and distance requirements, but are connected to different terminals on the VAV box controller. Three basic types of zone sensors can be installed:

• A zone sensor (required unless the box is used for flow tracking (refer to p. 187) or ventilation flow control (refer to p. 182))

• A zone sensor with setpoint (has a thumbwheel) (optional)

• A digital zone sensor with space temperature and setpoint (optional)

• A digital zone sensor with setpoint and On/Cancel buttons on the sensor

Note: The space setpoint thumbwheel zone sensor and the digital zone sensor are both available with an optional communication RJ-11 jack on the board and Timed Override request and cancel buttons.

Installing Hard-Wired Zone Sensors

Refer to Trane document 32703399, Installing the Tracer™ VV551 VAV Controller for the most recent information on wiring zone sensors to the VV550/551 controller, and X39641064, Tracer™ UC400 Controller Installation Sheet for the most recent information on wiring zone sensors to the UC400 controller.

An RJ-11 communication jack is an option available on all zone sensors. It permits access to the communications link and all the controllers on that link from the floor level in the space.

Installing a Digital Display Zone Sensor with Communication Stub

This digital zone sensor requires 24 Vac to operate.

Note: For wire lengths shorter than 75 feet (23 m), an 18 gage, 5 or 6 conductor cable may be used for 24 Vac power and signal wires. For wire lengths longer than 75 feet, use 18 gage, 3 conductor cable for signal wiring (TB2). Avoid routing wires near sources of electrical noise such as motors, fluorescent lights, LAN wiring, etc. In some high noise environments, signal wires may require shielding.

Installing a Wireless Zone Sensor

The Wireless Zone Sensor set includes a sensor and a receiver that work together to provide the same functions as the equivalent wired zone sensor. The receiver is wired directly to the VAV controller and reproduces signals is receives from the wireless zone sensor.

The sensor transmits the zone temperature, all zone temperature setpoint functions, and Timed Override Occupied (On) and Timed Override Unoccupied (Cancel) information to the receiver. Refer to the most recent version of Trane document BAS-SVX04-EN, Wireless Zone Sensor Installation, Operation, and Maintenance for detailed information on the wireless zone sensor and receiver.

Note: The RJ-11 communications jack is not available on the wireless zone sensor or receiver.

Use 18-22 AWG, stranded, tinned-copper, unshielded, twisted-pair wire when installing zone sensors. Best

Practice

Run power for the digital zone sensor from the VV550/551 or UC400 controller.Best

Practice



Installation

Installing the VAV Discharge Air Sensor

Install the VAV discharge air sensor 1-2 feet downstream of the VAV box in the discharge air duct (refer to Figure 6). The sensor provides feedback during auto-commissioning to verify the operation of the hot water valve, electric heat, parallel fan, and series fan. It can also be used for troubleshooting.

Installing a Hot Water Valve (Local Heat and Remote Heat)

Both the VV550/551 and UC400 controllers support local and remote hot water heat (remote usually means baseboard heat). Typical installations have either local or remote hot water heat but not both; however, both can be supported if there is no fan installed in the VAV box. Both controllers support two-position and modulating (3-point floating) control valves.

Install a discharge air temperature sensor in every VAV box. Best

Practice

Use 18-22 AWG, stranded, tinned-copper, unshielded, twisted-pair wire. Best

Practice

Figure 6. Discharge air sensor location (VAV box with series fan is shown)

From Plenum

FromAHU

Fan

ToSpace

Install the VAV discharge air sensorin the duct 1–2 feet downstreamof the VAV box

Use 18-22 AWG, stranded, tinned-copper, unshielded, twisted-pair wire. Best

Practice



Installation

Communications

For detailed instructions on communication wiring, refer to latest version of Trane document BAS-SVN03-EN, Unit Controller Wiring for Tracer SC Wiring Guide, the Tracer SC Installation guide, or to the installation guide for the applicable building automation system.

Preliminary LonTalk Communication Link Checkout Without Power

Perform this procedure without power applied to VAV boxes to test the link for level 4 communication before the boxes are put into service:

Note: Refer to “Preliminary Checkout for LonTalk Links,” p. 141 for more information on commissioning and troubleshooting the LonTalk communications link.

1. Install resistors at the ends of the LonTalk communication link.

2. Connect an Ohm meter to the communication link and measure the resistance. The resistance value should be approximately 52Ω + 2Ω per 1,000 feet (305 m) of communication wiring.

3. If the reading is inaccurate, go half the distance of the communication link and break it into two segments.

4. Measure the resistance of each segment. Each segment should read 105Ω + 2Ω per 1000 feet (305 m). The segment that does not check out contains the wiring issue.

5. Reconnect the segments.

6. Keep dividing the distance and retesting the link until the problem is isolated.

BACnet Communication Link Checkout

To isolate problems on the BACnet link, all the devices should be powered and installed on the Tracer SC. Refer to “Preliminary Checkout for BACnet Communication Links,” p. 144 for more information on commissioning and troubleshooting the BACnet communications link.

Power Considerations

Establish Power to the VAV Boxes

Installing high voltage power is typically the responsibility of the electrical contractor, especially if the VAV box is equipped with electric heat or a fan.

Important: If the VAV box is not equipped with electric heat or a fan, an alternate source of 24 Vac power is required.

Pull power from a near-by electric heat-equipped or fan-equipped VAV box, or centrally mount a 100 VA, 24 Vac step-down transformer (typically in a mechanical room for ease of access) and daisy-chain the 24 Vac power to the VAV boxes as described in “Design Considerations,” p. 12.

Note: Refer to the most recent version of Trane document number 32703399, Installing the Tracer™ VV551 VAV Controller for wiring best practices and information on installing and wiring the VV551 controller.

Note: Refer to the most recent version of Trane document number X39641064, Tracer UC400 Programmable Controller Installation Sheet for information on installing and wiring the UC400 controller.



Installation

Air Handler Connections

Static Pressure Sensor Location

Traditional Installation

Typically, the static pressure sensor is installed approximately two-thirds of the way down-stream of the longest supply-air duct. The system is then controlled to maintain a fixed static pressure setpoint that accounts for duct losses and represents an average supply duct static pressure (refer to Figure 7).

A Better Location

Implementing the fan static pressure optimization feature (refer to “Duct Static Pressure Optimization,” p. 157) of the Tracer SC VAS allows the sensor to be located anywhere along the length of the duct. This is possible because fan static pressure optimization resets the setpoint based on real-time system demand.

Benefits of installing the sensor in the recommended location:

• The sensor may already be mounted on the air handler.

• The installed cost is lower because of the shorter distance between the sensor and the controller.

• The installations are generally more reliable because there is less chance of damage to the wiring or pressure tubing.

Figure 7. Sensor located to report the average duct static pressure

Traditional location for the static pressure sensor

Best practice

X

X

Locate the duct static pressure sensor near the discharge of the fan in the supply duct.Best

Practice



Controller Setup

This section contains information on the proper sequence and best practices for configuring the components, and some considerations specific to the Tracer SC VAS, including:• Air handler checkout and configuring the air handler controller (AH540, MP580/581, LCI-R

Voyager/Precedent, LCI-I IntelliPak, BCI-I, BCI-R1)• Configuring the VAV box controllers

The following subsections describe equipment and controller setup performed with the Rover service tool or at the equipment user interface.

Air Handler Configuration

LonTalk discharge air controllers (DAC) are installed into the Tracer SC as VAV air handlers. When using MP580/581 programmable controllers, the DAC profile MUST be active.

Why Use a DAC Profile for an Air Handler on a LonTalk Link?

Using the DAC object or profile will save time and, consequently, money. The DAC has been mapped over to the VAV AHU equipment in Tracer SC to automate tasks that previously took significant time to set up. By using the DAC profile, Tracer SC automatically controls the occupancy, heat/cool mode, OA damper position, OA setpoint, static pressure, and the economizer functions of the air handler. In addition, standard equipment editors are automatically populated with data.

Note: If using an MP580/581 as the controller on the VAV air handler, enable (using the Rover service tool) the DAC profile, then install and map the MP580/581 in Tracer SC (refer to “Field-applied Controller Programming for Variable Volume and Constant Volume Air Handlers,” p. 47 for detailed information).

Table 2, p. 34 includes commonly used controllers on Trane AHUs, the tools used to configure them, and the equipment types created in Tracer SC for each.







Building Operator

BAS Technician

BAS Technician(s)

Service Technician

Install

Program

CommissionCommis

Operate

Optimize

Design

Maintain

1 Scheduled for release in 2010.



Controller Setup

Pre-Configuration Checkout

Before setting up the controller, perform a physical inspection of the air handler to verify that it is installed properly. Be sure to check the following items:• Are the door handles closed and locked?• Are the fire dampers open?• Are there filters installed?• Is the fan rotating in the correct direction?• Are the safeties in place?• Are the shipping bolts removed?• Are the starter fuses installed?• Are the access panels closed?• Did you remove the hard-wired zone sensor?

Confirming the list above is typically the responsibility of the mechanical contractor, but the startup technician should also verify these tasks.

Discharge Air Control

Typically, the first system on a VAV AHU to be commissioned and placed into operation is the static pressure control. The AHU fan, which is typically controlled by a Variable Frequency Drive (VFD) and a duct static pressure sensor, comprises the static pressure control system. The fan modulates to maintain the static pressure setpoint of the AHU as sensed by the duct static pressure sensor.

Static Pressure Sensor Control

Static pressure sensors can be mounted on the AHU either in the factory or in the field.

Factory-Mounted

All Trane unitary products have a static pressure sensor factory-mounted in the AHU. In most cases, the high pressure tubing connecting the sensor to the control panel is also factory-installed and no field installation is required. However, there are some exceptions; for instance the high pressure side of the static pressure sensor on Commercial Self Contained (CSC) units must be field-installed

Table 2. Common equipment and controller pairings

Equipment ControllerConfiguration

toolTracer SC equipment

type

Packaged climate changer(a)

M-series changer(a)

T-series changer(a)

100% outdoor air unitsCustom climate changersField-installed on existing air handlers

MP580/581 Rover

Constant volume or Variable volume air handler

UC400, UC600(b) Tracer TU

Voyager and Precedent RTUsLCI-R Rover

BCI-R(c) Tracer TU

IntelliPak rooftop units (RTUs)Commercial Self-contained units

LCI-I(d)

Local displayBCI-I(d)

VAV boxesVV550/551 Rover

VAV boxUC400 Tracer TU

(a) MP580/581s are sometimes used on these units.(b) UC600 is scheduled for release in 2011.(c) Scheduled for release in 2010.(d) All configuration for the IntelliPak is performed via the local display, but location label and baud rate is set using the appropriate service tool.



Controller Setup

to a pickup tube mounted in the discharge air plenum. Consult the equipment documentation for more details on the static pressure installation. Before starting any AHU, make sure the static pressure sensor and its associated tubing are present and properly installed.

Field-Mounted

Commission the static pressure sensor prior to starting the AHU. The most common field-mounted static pressure sensors are 4-20 mA devices that read pressure from 0-5 inH20. The specific information for the static pressure sensor being installed should be available on the device’s product data sheet.

Verify that the VFD responds to signals before sending a start command. Once the VFD has been checked out, start the drive in hand/manual at about 20 Hz to provide some airflow and static to the transmitter. If the transmitter reads static pressure, release the drive to auto and verify that it is being controlled to the static pressure setpoint.

General

Conduct a more comprehensive startup and checkout of the AHU including all temperature and humidity sensors, as well as all damper and airflow monitors. Refer to the documentation shipped with the air handler for more detailed information.

General LonTalk Controller Setup

Once the devices are properly installed and wired, use the Rover service tool in the passive mode to configure any AHUs and VAV LonTalk controllers.

There may or may not be a working SC at this stage in the installation. These instructions cover the best practices for setting up the AHU with the intention of configuring the VAS system later.

1. Connect a laptop directly to the LonTalk communication link using one of the following methods to connect the Rover cable:• Directly into an RJ-11 comm jack on the controller, if available, such as an MP581• To the supplied protection module and connect to the comm link at any controller• To a wired thermostat if it has the communication option and is wired to the LonTalk link

2. Launch the Rover service tool on the laptop (Figure 8).

Figure 8. Rover Service Tool



Controller Setup

3. Click LonTalk Configuration Only Service Tool (this is passive mode).

Note: If choosing LonTalk Service Tool (5), the Rover service tool starts in the passive mode, but the option to choose the active mode is presented there.

Note: The Rover service tool, version 7 and later, allows you to select the discovery domain (typically the zero-length domain) for installations managed by a non-Trane network managers.

4. The Rover Service Tool window displays and begins to discover all the devices on the LonTalk communication link. When finished, click on any device on the navigation tree and look at the configuration for that device.

5. Use the Rover service tool to identify a discovered device in the navigation tree.

a. Select Device > Identify... from the main menu.

b. The Rover - Press Service Pin dialog appears. Push the service pin on the air handler controller board. Do not hold the service pin down for longer than 15 seconds or the LonTalk controller will revert to unconfigured.

Note: A service pin can be sent two ways. The first is to press the service pin on the main board of the device (as described in step 5). A second way to initiate a service pin on Trane devices wired with a thermostat containing an ON button is to hold the ON button for 10 seconds and then release it. If the ON button option is not installed, shorting the zone temperature thermistor for 10 seconds produces the same result.

6. When a service pin is initiated, the device broadcasts its neuron ID on the LonTalk network. Rover highlights the device in the navigation tree and displays the appropriate editor for the device in the right pane.

Note: Turn off the auto identify feature in Rover as any time a service pin is received Rover opens the plug-in for that device.

7. Change the device name (location label) for the air handler to match the naming conventions specified below. Select Device > Rename from the menu. The device’s name becomes editable in the navigation tree. Click outside the name field to apply the name change.

Naming Devices

It is common to have multiple air handlers on a single LonTalk communication link, so it is important to have a naming convention that allows you to quickly and accurately identify an AHU and the VAV boxes it serves.

Example: You have two air handlers on the LonTalk link (one MP580 identified as AHU 1 on the blueprint and one IntelliPak rooftop unit identified as RTU 2 on the blueprint). Name those air handlers AHU 01 MP580 and RTU 02 IPAK (refer to Table 3, p. 37). Subsequently, name the VAV boxes served by the MP580 with base names of VAV 01 along with extensions identifying individual boxes (VAV 01-01, VAV 01-02, etc.). Base names for VAV boxes served by the IntelliPak would be VAV 02 along with extensions (VAV 02-01, VAV 02-02, etc.). Be sure to use a “0” to designate numbers less than 10 (e.g., 01, 02, 03, etc.) or the items will not sort into correct numerical order if there are more than 10 devices on the link.

Name the air handler based on the blueprint name. Using a number also helps to tie the air handler and the VAV box together. This is useful when you are viewing devices in Tracer SC and when you perform air and water balancing using the Rover service tool, where devices are sorted.

BestPractice



Controller Setup

Controller Setup (LCI-R DAC)

The LCI-R comes in two configurations: constant volume (SCC) and variable air volume (DAC). You must use the LCI-R controller with the DAC configuration for the Tracer SC VAS.

1. The initial steps for setting up this controller are the same as those for the AH540/541 controller “General LonTalk Controller Setup,” p. 35 and “Naming Devices,” p. 36 before continuing with step 2 below.

2. Verify that the LCI-R is a DAC controller by viewing the program ID number (Figure 9), which should be 80 00 2A 56 0A 03 04 XX. XX indicates the software revision of the .xif program. The XX numbers may not run sequentially from one version to the next. However, the program ID numbers before the XX number will always be the same for a DAC controller manufactured by Trane. The alpha-numeric sequence “0 00 2A” in the program ID identify it as a Trane controller.

Note: The Active Group View is the first view that displays when the Rover service tool is discovering the link. Active Group View does not mean the active tool mode of the Rover service tool.

3. Select the LCI-R DAC Unit tab. (Make sure the Morning Warm-up Enable check box is selected.)4. Select the Setpoints tab.

• Verify the Duct Static Setpoint value is correct (refer to the specifications for the project)

• The Economizer Minimum field in the IAQ Setpoints group should be at 15%. Make sure it is not set to 0% or 100%

Note: The air balancer should specify a different Economizer Minimum value.

Table 3. Best Practices for Naming Devices

AHU Name VAV Box Name

AHU 01 MP580 VAV 01-01

VAV 01-02

VAV 01-03

VAV 01-04

VAV 01-05

RTU 02 IPAK VAV 02-01

VAV 02-02

VAV 02-03

VAV 02-04

VAV 02-05

Figure 9. Program ID in the Active Group View



Controller Setup

5. Click Download to send the new configuration to the LCI-R DAC controller.6. Click Save to save the configuration for the AHU using the device name as the configuration

file name. Configuration files have an “.rcf” extension after the file name.

Note: Create a subdirectory identifying the job name beneath the Rover/Config/ directory on the hard drive (e.g., Rover/Config/”Job Name”/”Device Name.rcf”).

Controller Setup (IntelliPak)

Refer to “Field-applied Controller Programming for Variable Volume and Constant Volume Air Handlers,” p. 47 for specific information on configuring the MP580/581 controller and (“Controller Setup (BCI-I),” p. 39) for specific information on configuring a BCI-I controller.

Controller Setup (both LCI-I and BCI-I)

The LCI-I and the BCI-I controller must be configured using the operator display on the unit itself (refer to Figure 10). Do this before performing setup for the specific controllers.

1. At the IntelliPak controller panel, press Configuration (the default password is “+---”).

2. Press Next to navigate to the BAS Communications Module: setting. Make sure it is set to Installed.

3. Press Setup.4. Press Next to navigate to the Unit Control: setting. Make sure it is set to BAS Network.5. Press Next to navigate to the VAV Control Functions: menu. 6. Press Enter.7. Press Next to navigate to the VAV Box Max Stroke Time: setting. Make sure it is set to 0 Min8. Press Previous to navigate back to the VAV Control Functions: menu.9. Press Next to navigate to the Morning Warm-up: setting. Make sure it is set to Enabled.10. Press Next to navigate to the Daytime Warm-up: setting. Make sure it is set to Enabled.

Figure 10. IntelliPak operator display



Controller Setup

Controller Setup (LCI-I)

Note: IntelliPak II may support humidification and dehumidification functions. Refer to the IntelliPak II Rooftop, Programming Troubleshooting Guide for Commercial Single Zone Rooftop Air Conditioner with Variable Air Volume (VAV) Controls, RT-SVP04C-EN to set up those functions.

Note: You cannot configure the LCI-I (IntelliPak) controller with the Rover service tool.

1. Configure the LCI-I controller as described in “Controller Setup (both LCI-I and BCI-I),” p. 38 using the IntelliPak’s local display.

2. Press Next to navigate to the Software Revision Number Report: settings (the number varies depending on the number of boards installed), confirm that the latest software versions are loaded. If not, flash download the software revision to the latest version you have available in the Rover service tool.

a. Make sure you have the latest Rover service pack downloaded before moving to step b below. Downloads are available at http://tranenetlax1/GCC_Downloads/Home/Downloads/Rover.asp, or publicly at www.trane.com, at the site select: Commercial > US > Software Downloads > Select GCC Downloads.

b. Look in the C:\program files\Rover\images directory for the latest LCI-I image (e.g., 0003_LCI-I_Appl_1_13_5.img).

Controller Setup (BCI-I)

To retrofit a BCI-I controller in the field:

1. Install the BCI-I controller on the IntelliPak (refer to the BACnet BCI-I Installation Guide, RT-SVN13A-EN).

2. Configure the BCI-I controller as described in “Controller Setup (both LCI-I and BCI-I),” p. 38 using the IntelliPak local display.

3. Set the rotary address (MAC address or device ID). The rotary address is where the Tracer SC will discover the BCI-I controller and is limited to values between 1 and 120. The address you set should be unique on the link.

Important: If you change the MAC address (change the rotary switches) after the BCI-I is powered up, cycle power on the BCI-I to initialize the new address.

4. Power up the BCI-I controller. The BCI-I controller communicates with the Tracer SC and self-configures based on the configuration settings in the IntelliPak.

5. Connect Tracer TU.6. Make sure the baud rate is set correctly.

a. Navigate to Utilities > Controller > Controller Settings. The Controller Settings tab appears.

b. Set the baud rate to 76800 in the Protocol section.

Important: Make sure all devices on the BACnet link are set to the same baud rate.

7. Click Save to download the controller settings to the BCI-I.

Use these settings for an IntelliPak when it is part of a VAS:• BAS Communications Module: Installed (Config menu)• Unit Control: BAS Network (Setup menu)• Software Revision Numbers: Latest versions for all• VAV Box Max Stroke Time: 0 Min• Morning Warm-up: Enabled• Daytime Warm-up: Enabled

BestPractice



Controller Setup

VAV Box Configuration

Before setting up the VAV box, perform a physical inspection to verify that it is installed properly. Be sure to check the following items:• The VAV box controller is powered.• The local disconnects for any electric heat or fans are ON (energized).• The components are wired correctly (fans, electric heat, temperature sensors, etc.).• The tubing from the differential pressure sensor to the flow ring is connected and not damaged

(the tubing can come loose or get pinched during installation).

After the VAV boxes are properly installed and wired, set up the controller using the appropriate service tool (Rover for VV550/551 controllers and Tracer TU for UC400 controllers). There may or may not be a working Tracer SC at this stage in the installation; however, a working air handler is required to set up and commission the VAV boxes. These instructions cover the best practices for setting up the VAV boxes when you know you will also be configuring a VAS system.

VV550/551 Controller Setup

Perform the following steps to set up a VV550/551 controller:

1. Connect the laptop directly to the LonTalk communication link.

Note: Connect to the LonTalk link directly at the VV550/551 controller board through the Comm Tool inputs (TB2-1 and TB2-2) or an RJ-11 jack, or plug into the communications jack on any one of the zone sensor communication stubs.

2. Launch the Rover service tool and discover the LonTalk devices on the link as was done for the air handlers (refer to “Pre-Configuration Checkout,” p. 34).

3. At this point, start moving from VAV box to VAV box making sure each box and its components are installed correctly (testing sensors, dampers, valves, etc.) and setting them up to work properly with the VAS, which will be created later. Select Device > Identify... from the main menu

4. The Rover - Press Service Pin dialog displays. Go to the VV550/551 being set up and do one of the following:

• Push the service pin on the VV550/551 board.

• If the VAV box has a zone sensor wired to it, push the ON button on the zone sensor and hold it for 10 seconds.

• If the zone sensor is not installed, short the zone sensor inputs (TB-1 and TB-2) for 10 seconds.

5. The Rover service tool highlights the device in the navigation tree and displays the editor in the right pane.

Note: If the node state of the LonTalk device is set to unconfigured, “unconfigured” displays on the Rover active group screen. This does not mean that the VV550/551 is not configured properly. It means the device does not have a network address. An address is assigned during Tracer SC setup.

6. Change the device name (location label) for the VAV box to match the naming conventions described for air handlers (“Naming Devices,” p. 36). Select Device > Rename from the menu. The device’s name becomes editable in the navigation tree. Click outside the name field to apply the name change.

7. Click Configuration.



Controller Setup

8. On the Setpoints tab (Figure 11), verify that the following information is correct:

• Default setpoints are the heating and cooling setpoints the VV550/551 uses as default values. Refer to the Tracer VV550/551 VAV Controller Installation and Operation manual, CNT-SVX17*-EN for a detailed explanation of how these setpoints are used by the controller.

• The Enable Auto Calibration check box is selected. This enables automatic calibration when the power cycles or the operating mode changes to Unoccupied.

• The Enable Thumbwheel Setpoint and Enable Thumbwheel Star and Double Star Function check boxes are not selected.

Note: It is possible to use the Enable Thumbwheel Star and Double Star function for air-balancing without using the Rover air and water balancing tool, but it is easier to use the tool, so Trane recommends using it.

9. Click the Unit tab.

a. Select Space Temperature in the Control Type group. Best practices dictate that the VV550/551 is configured this way. If setting up a ventilation flow or a flow tracking system, refer to “Special Applications,” p. 181 for detailed information.

b. In the Box Setup group, select the item that corresponds to the VAV box. If using a Trane F-Style box, also select the size of the box from the drop-down list box.

c. Auto Changeover Setpoint — this setpoint determines the heat/cool action of the VAV box based on a comparison between this setpoint and the temperature of the primary air in the duct.

10. Click the Setup tab.The ventilation setup fields define the Occupied and Standby Outside Air cfm setpoint requirements for the VAV. This information is typically found on the job specification.

11. Click the Inputs tab.Analog input 4 is configurable for a primary supply air sensor or discharge air sensor. The best practice is to install and configure the sensor for discharge air.

12. Click the Outputs tab.Use the Output Configuration Wizard to set up the heating options for the VV550/551.

Figure 11. Rover VV550/551 Configuration editor



Controller Setup

13. Click the Other tab and go to the Timers group.

a. Type 0 minutes in the Occupied Bypass Timer field. This allows the VAV box to request the Occupied Bypass but the Tracer SC system to control the amount of time the VAS is in Occupied Bypass mode.

b. Set Manual Override Time to 600 minutes.

c. Set the Power-up Control Wait to 300 seconds.

14. Click Download to send the configuration to the VV550/551.15. Click Save to save the configuration for the box using the device name as the configuration file

name. Configuration files have an .rcf extension after the file name.

Note: Create a subdirectory identifying the job name beneath the Rover/Config/ directory on your hard drive (e.g., Rover/Config/”Job Name”/”Device Name.rcf”

16. After configuring all devices on the link, take a screen capture of the Rover Active Group view. This screen capture allows you to see a high-level view of the link as it existed just after you set it up. This view provides useful information (specifically, the Program ID, Neuron ID, and device names) should you ever have to recover or remember the settings.

a. Click the Active Group icon at the top of the navigation tree to access the Active Group View.

b. On your keyboard, hold the Alt + Print Screen (Prnt Scrn) keys down at the same time and then release.

c. Open WordPad (this is a simple text editor that allows you to paste an image of the screen you captured into the page and save it as a file. WordPad is a standard Windows application. To launch WordPad, click Start > Programs > Accessories > WordPad.

d. Click somewhere in the open document and select Edit > Paste (Ctrl + V) from the main menu.

e. The Rover Active Group view should display in the WordPad document.17. Save the WordPad file in the same directory where each of the configuration files was saved

(the WordPad files has an “.rtf” extension).

Figure 12. Rover Service Tool Configuration editor, Other tab



Controller Setup

UC400 Controller Setup

Perform the following steps to set up a UC400 controller:

1. Set the rotary switches to the appropriate address prior to powering up. Valid addresses are from 1 to 120.

2. Connect the laptop directly to the UC400.

• Connect directly using the USB port on the device

• Connect using the comm port on the wall sensor (which is wired to the UC400 using the IMC bus) using the Tracer TU adapter (refer to X39641115-01A, Tracer TU Comm Adapter Installation Sheet)

• Connect using Tracer TU and the Tracer SC (to communicate with a UC400 this way, the VAV boxes must be installed on the Tracer SC)

Note: Skip step 3 if the VAV box has a factory-installed UC400 controller.

3. Set the configuration of the VAV box (only if it is not configured at the factory). Using the Tracer TU service tool, access the configurator via Utilities > Equipment > Configuration (refer to Figure 13, p. 44). Configure the VAV box.

Note: If you reconfigure the VAV box using the Configurator after the VAV box has been installed in the Tracer SC, you must delete and then reinstall the VAV box in the Tracer SC.

4. Click Save.

• The address for each device on a single BACnet link should be unique. However, even if there are two BACnet links, define unique addresses for each device (for example, do not put a device 002 on BACnet link 1 and a device 002 on BACnet link 2).

• Keep a separate record that includes the name of the VAV box, its rotary switch setting (MAC address or device ID), and the name of the controller.

BestPractice

Important: • If you have custom programming in the controller, be sure to back up those programs before running the configurator. The configurator will wipe out all programming in the UC400.

• Saving the configuration wipes out any old configuration data on the controller



Controller Setup

5. Select Utilities > Controller > Controller Settings. The controller settings page appears (refer to Figure 14).

a. Change the device name for the VAV box to match the naming conventions described for air handlers (“Naming Devices,” p. 36).

b. Set the controller units (the units selected must match the Tracer SC system units).

c. Set the baud rate; the default is 76800. All devices on the link must have the same baud rate.

Figure 13. VAV box configuration



Controller Setup

6. Click Save.

7. Verify the setpoints. Select Utilities > Equipment > Setpoints to define the setpoints and setpoint limits (refer to Figure 16).

8. Click Save.

Figure 14. Controller Settings

Figure 15. Verifying setpoints



Controller Setup

9. Configure the Setup Parameters. Select Utilities > Equipment > Parameters to define the following parameters (refer to Figure 16, p. 46).

a. Click the Ventilation tab. Set the Occupied and Standby Ventilation Setpoints.

b. If performing ventilation control based on CO2, verify the space CO2 low and high limit setpoints.

c. Click the Airflow Setup tab. Verify all of the airflow setpoints for the VAV box (as specified).

d. Verify that all other parameters were configured properly in Step Note:.

10. Click Save.

11. The UC400 is now ready to be installed in the Tracer SC.

Note: Select Utilities > Equipment > Commissioning to assist with auto-commissioning and air balancing the VAV box.

Figure 16. Setup Parameters



Field-applied Controller Programming for Variable

Volume and Constant Volume Air Handlers

Important: Fully program the controller before installing it in Tracer SC. Changing the programming after it is installed in Tracer SC requires that you delete and reinstall the equipment again.

Whether is was installed in the factory or in the field, the controller must first be configured and programmed using the appropriate service tool (Rover for MP580/581 or Tracer TU for UC400).

To see some of the most popular system and equipment configurations available from Trane, visit the following address on Trane.com:

http://www.trane.com/Commercial/DesignAnalysis/PopularSystemConfigurations.aspx?i=2352

Programming the MP580/581

This section provides the steps required to set up your MP580/581 to work properly with a Tracer SC VAS:

1. Locate the appropriate Pre-Packaged Solution for the air handler configuration you are using and download it.

2. Download the configuration file (.rcf) onto the MP580/581.

3. Verify that the DAC/SCC profile is enabled in the MP580/581 object using the Rover service tool (refer to “Enabling Profiles for the MP580/581 Object,” p. 48).

Important: VAV Air Handlers

If the MP580/581 does not have the DAC profile enabled for a variable volume air handler, it will not be available as a selectable AHU by the Tracer SC VAS.

Constant Volume Air Handlers

If the MP580/581 does not have the SCC profile enabled for a constant volume air handler, it will not be available as a selectable AHU by Tracer SC Area.







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Use Pre-Packaged Solutions whenever possible to minimize configuration and programming time.Best

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Field-applied Controller Programming for Variable Volume and Constant Volume Air Handlers

4. Download the Pre-Packaged Solution TGP routines onto the MP580/581.

Important: You MUST use the associated graphics TGP routines in the Pre-Packaged Solution to properly assign inputs, outputs, and setpoints to the appropriate LonTalk network variables.

5. Discover and install an MP580/581 device using Tracer SC. Refer to “Install and Set Up the Variable Air Volume Equipment Types,” p. 73.

Enabling Profiles for the MP580/581 Object

Be sure to enable the DAC or SCC profile on the MP580/581 controller if the equipment is a variable volume or constant volume air handler. This allows the profile data in the MP580/581 to map correctly to the air handler equipment in the Tracer SC (i.e., nvospacetemp maps directly to the equipment space temperature point). Figure 17 shows the location of the DAC and SCC Profile selection options in the Rover service tool.

Enabling the appropriate profile causes the DAC or SCC tab to display in the Rover service tool Configuration editor (Figure 18, p. 48). The tab contains the specific air handler configuration parameters for the MP580/581.

Figure 17. Enabling a profile using the Rover service tool (DAC profile enabled is shown)

Figure 18. DAC tab in the Rover Service Tool




Configure the Inputs/Outputs/Variables

1. Configure, the inputs, outputs, and variables needed on the MP580/581 controller. Refer to Tracer MP580/581 Programmable Controller Programming guide, CNT-SVP01C-EN for detailed instructions.

Note: If you are not using Pre-Packaged Solutions, use names that are meaningful, but do not make specific reference to the air handler (i.e., use “Supply Air Temp” but not “AHU 1 Supply Air Temp”). This allows you to configure points on the first MP580/581, and save the configuration as a template. This configuration file can be reused to configure additional air handlers of the same type.

2. Save the configuration file.

Note: If working offline, save the configuration to your hard drive for downloading at a later time.

3. Download the configuration file to the MP580/581 controller.

Install the MP580/581 on the Tracer SC

To install the MP580/581 on the Tracer SC (refer to “Install and Set Up the Variable Air Volume Equipment Types,” p. 73 for more detailed information):

1. Initiate a discovery for all LonTalk devices connected to the Tracer SC.

2. From the discovered device list, select the MP580/581 and click Install.

The MP580/581 is listed in three places after it is installed on the Tracer SC.

• All MP580/581s with DAC profiles enabled will show up in the Variable Volume Air Handler list under Equipment in the left-hand navigation bar.

• All MP580/581s with SCC profiles enabled will show up in the Constant Volume Air Handler list under Equipment in the left-hand navigation bar.

• All MP580/581 with no profile defined will show up in the Generic list under Equipment in the left-hand navigation bar.

When an MP580/581 device is installed, Tracer SC evaluates the configuration data in the .rcf file and creates BACnet points on the Tracer SC to represent that configuration. Table 4, p. 49 shows which equipment is created when an MP580/581 is installed on a Tracer SC. Table 5, p. 50 shows the points that are created.

Important: Make sure to program the MP580/581 using the same units of measure that are being used by the Tracer SC system units.

Use the .rcf file provided with the Pre-Packaged Solution.Best

Practice

Table 4. Created Equipment on the Tracer SC for MP580/581

MP580/581 Configuration

Created on SC

Variable VolumeAir Handler

Constant VolumeAir Handler

ProgrammableController

SCC x

DAC x

Generic x




Important: If you change the MP580/581 point configuration, you must “replace” the device in the Tracer SC before the new point configuration is recognized. To replace the device:

1. Select Installation > Device from the left-hand navigation.

2. Select the device that you want to replace from the list.

3. Click actions... > replace device.

Table 5. Points created for Programmable MP580/581 Equipment in Tracer SC

MP580/581 Point Type Tracer SC Point Number created on SC Comments

Universal input (1-36)Analog or Binary Input (depending on point configuration in the MP580/581)

DynamicOnly creates points for configured inputs

Binary Output (1-30) Binary Input DynamicOnly creates points for configured inputs

Binary Output Request Tracer (1-30) Binary Output DynamicOnly creates points for configured outputs

Analog Output (1-30) Analog Input DynamicOnly creates points for configured outputs

Analog Output Request Tracer (1-30) Analog Output DynamicOnly creates points for configured outputs

Binary Variable Local (1-120) Binary Input DynamicOnly creates points for configured local variables

Binary Variable Summit: Tracer (1-30) Binary Output 30

Analog Variable Local (1-120) Analog Input DynamicOnly creates points for configured local variables

Analog Variable Summit: Tracer (1-30) Analog Output 30




Integrating the MP580/581 Controller with Tracer SC

BACnet to LonTalk Communication

Tracer SC uses BACnet points within Tracer SCs to represent LonTalk controllers. BACnet output points (analog, binary, and multistate) are used to send data from the Tracer SC to the LonTalk controllers. BACnet input points (analog, binary, and multistate) in the Tracer SC are used to read data from the LonTalk controllers. Both output and input point types are created automatically when the device is installed in the Tracer SC.

Figure 19. BACnet to LonTalk communication

Tracer SCBrowser

MP580/581Controller

LonTalk Communications Link

VV550/551

VV550/551

VV550/551

VV550/551

SC SC SC

Ethernet Link

BACnetLonTalk

AI, AO, BI, BO,MI, MO

Equipment




LonTalk Profile Network Variable Associations

Figure 20 shows the association between the data on the MP580/581 editor (Configuration page) in Tracer SC, and the corresponding profile TGP blocks associated with the LonTalk network variables. This is how information is communicated from Tracer SC to the MP580/581 controller.

Figure 20. Network variables associated with the MP580/581 editor

Associated TGP Program block




Communicating Operating Mode

Tracer SC applications use the concept of operating mode when communicating control commands to equipment. LonTalk devices do not use the operating mode concept; they pass information back and forth using network variables. To overcome the difference, Tracer SC converts the operating mode to occupancy commands and heating/cooling commands, which are communicated to a LonTalk controller using the network variables nviApplicMode and nviOccSchedule (refer to Figure 21, below, and Table 6, p. 54).

Table 6, p. 54 shows the relationship between the operating mode and the occupancy request and heating cooling request for non-VAV air handlers and VAV air handlers.

The heating cooling request requires additional calculation in order to determine the behavior of the equipment in certain operating modes.

Important: The heating cooling request calculations for all equipment (except VAV air handlers) are made using values from the equipment:

• The Heating Cooling Mode Request is Morning Warm-up if the Space Temperature Active is below the Space Temperature Setpoint BAS or if either value is invalid.

• The Heating Cooling Mode Request is PreCool if the Space Temperature Active is above or equal to the Space Temperature Setpoint BAS.

The heating cooling request calculations for all VAV air handlers are made using values from the Tracer SC VAS:

• The Heating Cooling Mode Request is Morning Warm-up if the VAS Average Space Temperature is below the VAV AHU Startup Setpoint or if either value is invalid.

• The Heating Cooling Mode Request is PreCool if the VAS Average Space Temperature is above or equal to the VAV AHU Startup Setpoint.

Figure 21. Operating mode to LonTalk network variable

Tracer SC MP580/581 Controller

Operating Mode

LonTalkCommunications

Link

TGPnviApplicMode

nviOccSchedule

Heating/Cooling Request

Occupancy Request




How to Translate Operating Mode to LonTalk Network Variables

To determine the corresponding values for nviApplicMode and nviOccSchedule given an operating mode, use Table 6 and follow the steps below:

1. Locate the operating mode in column 1.

2. Determine what type of equipment you have installed.

a. For all equipment except VAV AHUs, use columns 2 and 3.

b. For all VAV AHUs, use columns 4 and 5.

3. The corresponding value of nviOccSchedule is shown in columns 2 or 4.

4. The corresponding value of nviApplicMode is shown in columns 3 or 5.

Using Tracer Variables to Control the MP580/581

The MP580/581 has 30 binary and 30 analog variables, which are mapped to the Tracer SC when the MP580/581 is installed on the Tracer SC. The Tracer SC automatically creates 30 analog outputs and 30 binary outputs with the names created for the 60 Tracer variables in the MP580/581.

Note: If no name is assigned to a variable in the MP580/581, then the default name for that variable is created in the Tracer SC (e.g. Tracer Summit Analog Variable 17).

These points are found on the Configuration page of the MP580/581. To get to this page:

1. Select Equipment > Programmable or Constant Volume or Variable Volume from the left-hand navigation list (depending on the type of MP580/581 installed).

2. Select the appropriate MP580/581 from the list.

3. Click Configure.

Table 6. Operating mode relationship to Occupancy Request and Heat Cool Mode Request for MP580/581

Operating Mode

All Equipment except VAV AHUs VAV AHU

Occupancy Request

Heating Cooling Request

Occupancy Request

Heating Cooling Request

Occupied Occupied Release Occupied Release

Unoccupied Unoccupied Release Unoccupied Off

Unoccupied Heat/Cool OccupiedMorning Warm-up(a)

PreCool(a) OccupiedMorning Warm-up(b)

PreCool(b)

Night Purge Occupied Night purge Occupied Night Purge

Optimal Start OccupiedMorning Warm-up(a)


PreCool(b)

Optimal Stop Standby Release Occupied Release

Unoccupied Humidify OccupiedMorning Warm-up(a)


PreCool(b)

Unoccupied Dehumidify OccupiedMorning Warm-up(a)


PreCool(b)

Humidity Pull down OccupiedMorning Warm-up(a)


PreCool(b)

(a) Heat Cool Mode Request calculations are calculated using properties from the equipment: Heating Cooling Mode Request is Morning Warm-up if the Space Temperature Active is below the Space Temperature Setpoint BAS or if either value is invalid.Heating Cooling Mode Request is PreCool if the Space Temperature Active is above or equal to the Space Temperature Setpoint BAS

(b) Heat Cool Mode Request Calculations are calculated by the VAS based on the following:Heating Cooling Mode Request is Morning Warm-up if the VAS Average Space Temperature is below the VAV AHU Startup Setpoint or if either value is invalid.Heating Cooling Mode Request is PreCool if the VAS Average Space Temperature is above or equal to the VAV AHU Startup Setpoint




You can override any Tracer Variable on the MP580/581 controller from the Tracer SC MP580/581 Configuration page (refer to Figure 22, p. 55).

You can also create TGP2 programs on the Tracer SC that can read any value from the system, which in turn controls a Tracer variable on the MP580/581 (refer to Figure 23, p. 56).

Figure 22. Example: Tracer SC MP580/581 Configuration page




How to use an MP580/581 with Ventilation Optimization in VAS

To set up ventilation optimization, you need to send the VAS ventilation optimization outdoor airflow setpoint to the MP580/581. Here is how to do it:

1. Use the Rover service tool to program the MP580/581 using the appropriate Pre-Packaged Solution.

2. Install the MP580/581 on the Tracer SC.

3. Program the Area on the Tracer SC.

4. Program the VAS on the Tracer SC Create Variable Air System wizard.

a. Enable ventilation optimization on the first page.

b. Select the VAV boxes to participate in ventilation optimization on the Configure Members page.

c. Enter a value for the startup air flow setpoint, which sets the outdoor air flow for the air handler when it starts.

5. Open Tracer TU service tool.

6. Discover the Tracer SC.

7. Launch the TPG2 editor.

8. Create a program in the Tracer SC (refer to Figure 24) that reads the ventilation optimization air flow setpoint from the VAS and writes the value to the MP580/581 Tracer Analog Variable that represents the outdoor air flow setpoint.

9. Compile and download the program to the Tracer SC.

Figure 23. Example of how a point controls a Tracer variable on the MP580/581

Figure 24. TGP2 program to communicate the outdoor air flow setpoint to the MP580/581




Tracer Graphical Programming (in the MP580/581 using Rover)

If you cannot us a Pre-Packaged Solution, there are several TGP programs in the TGP\Library\AHU - VAV Plus directory created specifically to interface with building automation systems using the LonTalk communication protocol. The TGP programs ship with the Rover service tool software and are saved into this directory when you install the Rover service tool. To download the latest versions of these programs along with the service packs for the Rover service tool go to http://tranenetlax1/GCC_Downloads/Home/Downloads/Rover.asp

These TGP programs are written specifically for VAV air handler operations (controlling the fan, controlling the discharge air, etc.). Refer to the MP580/581 Programming Guide, CNT-SVP01C-EN for detailed information on creating and modifying TGP.

The following sections give a brief description of the TGP and the logic the programs use to allow the MP580/581 to control the air handler as a DAC object. To access these programs:

1. In the Rover service tool, click Program Editor.

2. When the TGP editor appears, select File > Open... from the menu. The Open window appears.

3. Navigate to the C:\TGP\Library\AHU - VAV Plus directory and highlight the appropriate file.

4. Click Open.

When the appropriate TGP program displays in the editor, you will see the unmapped inputs, outputs, and variables in the editor (red text). Map these to the corresponding inputs on the MP580/581 for each of the programs. (Refer to the MP580/581 Installation and Programming guide for specific information on mapping inputs to a network variable.)


Practice

Configure as many points as possible before modifying the TGP programs and installing the MP580/581 in Tracer SC. This will allow you to work most efficiently.Best

Practice




Pre-Packaged Solutions Sample PPS Graphics.tgp

The program shown in Figure 25 communicates status information from the MP580/581 back to Tracer SC using LonTalk network variables (NVOs).

Figure 25. Communications.tgp




Programming the Field-Applied BACnet Unit Controllers

Important: Fully program the controller before installing it in Tracer SC. Changing the programming after it is installed in Tracer SC requires that you delete and reinstall the equipment again.

Whether is was installed in the factory or in the field, the controller must first be configured and programmed using the appropriate service tool (Rover for MP580/581 or Tracer TU for UC400).

Tracer UC400 Controller

Refer to BAS-SVP06A, UC400 Programming Guide for detailed information on programming the UC400 controller when used for VAV applications in Tracer SC air systems. The UC400 Programming Guide describes the following:

• How the UC400 controller functions on the Tracer SC BACnet Communications Link

• How to set up the UC400 controller on the Tracer SC BACnet Communications Link (also refer to “UC400 Controller Setup,” p. 43), including:

– Loading firmware

– Creating and commissioning hardwired points

– Converting TGP programs to TGP2 programs

– Creating custom points required by TGP2 programs

– Installing system-level programs and communicated values on the Tracer SC

– Creating UC400 templates on the Tracer SC

• Programming best practices

• Special techniques, issues, and considerations

• UC400 profile descriptions and related files

• How to use macros

• A master points list


Practice



VAV System Overview

Controlling a variable air volume system with Tracer SC requires coordinating three standard applications:

• Schedules

• Area Control

• Variable Air System (VAS)

The 1st Street Office Building shown in Figure 26, p. 61 will be used to demonstrate how these applications interact to successfully control the system.

Description: The 1st Street Office Building is equipped with 25 VAV boxes and one air handler and controlled by Tracer SC.

The 1st Street Office Building is occupied by two tenants: AAA Moving Company (served by 10 parallel fan powered VAV boxes) and Eastside Law Offices (served by 10 parallel fan powered VAV boxes). A common space is shared by both tenants. It is comprised of the hallways, two conference rooms, and a mechanical room (served by 4 shutoff VAV boxes), and the bathrooms (served by 1 parallel fan powered VAV box).

The physical layout of the building lends itself to being divided into two Tracer SC Areas and a common space (refer to Figure 26, p. 61). For this example, the Areas are called AAA Moving and Eastside Law Offices.

By creating a Tracer SC Area for each tenant, the building owner can create individual schedules for each tenant and allow them each the separate ability to override the schedule when they work outside of normal business hours.







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VAV System Overview

Common Spaces

By design VAV air handlers will still produce approximately 20% airflow to the system at their minimum flow settings. To account for this, the VAS uses common space VAVs to prevent over-pressurization of the ductwork when the central fan is delivering minimum airflow to the system. By providing a place to put excess air, the common space VAVs allow the air handler to run when it is asked to provide more airflow than the VAV boxes in an Area can deliver.

Example: At 4:15 PM, the Eastside Law Offices are Unoccupied (0 cfm) and the AAA Moving Area VAV boxes are maintaining an airflow of 1975 cfm to the space. RTU-01 is operating at 22 Hz and delivering 2500 cfm (which is the minimum cfm the central fan can provide). Without the common space VAV boxes, the excess air (525 cfm) would over-pressurize and potentially damage the ductwork.

Common spaces do not need to be scheduled because the VAS controls the common space VAV boxes to match the highest ranking operating mode of the non-common space VAV boxes (refer to “How Area and VAS Interact,” p. 66). Where each tenant is defined by an Area and common spaces are shared, the common spaces are managed by the VAS and do not have to be members of either Area.

Important: When no clearly defined “common space” exists (i.e., a hallway, stairwell, etc.), or there is a need for timed override of the space served by the common space VAV box, then the common space VAV box should be a member of an Area. This is a new feature associated with Tracer SC. Previously, Tracer Summit could not have common space VAV boxes as members of an Area.

Figure 26. Physical layout and Areas in the 1st Street Office Building



VAV System Overview

In Figure 26, p. 61, the two conference rooms, the bathrooms, and the hallways have been designated as common spaces. Lobbies, hallways, rest rooms, and utility rooms are good candidates for common space VAVs, because the excess airflow and any associated noise are less noticeable by the tenants.

Defining Areas and Selecting Area Members

The number of Areas needed and the size of those Areas will be dictated by the physical layout (office groupings, walls, etc.) and the logical layout (different tenants, different departments, etc.) of the building.

In the earlier example, one Tracer SC Area will be created for each of the tenants in the 1st Street Office Building: AAA Moving and Eastside Law Offices. (Refer to “Set Up Areas,” p. 75 for detailed information on setting up Areas).

Once the Areas are defined, the VAV boxes that will serve the respective zones need to be assigned as Area members. For the 1st Street Office Building example, the VAV boxes would be assigned to the Areas as defined in Table 7 and shown in Figure 27, p. 63.

The number of VAV boxes in the smallest Area plus the number of common space VAV boxes should add up to at least 20% of the total number of VAV boxes in the VAS.

Note: When selecting the VAV boxes make sure they can accommodate 20% of the total design airflow.

BestPractice

Table 7. Area members

Area VAV Box #

AAA Moving 1-10

Eastside Law Offices 11-20



VAV System Overview

Note: In this example, common space VAV boxes cannot initiate timed overrides of the Areas and there is no logical Area for them to be a member of, so they are not members of any Area.

Figure 27. Area VAV members

Area:AAA Moving

VAV boxes 1-10 VAV boxes 11-20

Area:Eastside Law Offices

VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV VAVVAV



VAV System Overview

Assigning the VAS Members

The VAS is a virtual representation of the physical equipment in the building (that is the air handler and the VAV boxes)(refer to Figure 28) with the ductwork providing the airflow path.

The members of the VAS are the VAV air handler, all the VAV boxes served by the air handler including the common space VAV boxes, and the exhaust fan (refer to Figure 29, p. 65).

Figure 28. 1st Street Office Building physical air system layout



VAV System Overview

Note: There should only be one air handler as a member of the VAS.

Figure 29. AHU and VAV members in the VAS

VAV VAVVAV VAV

EF

VAV

Common SpaceVAV boxes 21-25

Eastside Law Offices VAV boxes 11-20AAA Moving VAV boxes 1-10

RTU 01 VAS

RTU 01


VAV AHU =

VAV boxes &Exhaust Fan =

Tracer SC Application =



VAV System Overview

How Area and VAS Interact

The VAV boxes that are members of both an Area and the VAS connect the two applications in Tracer SC.

The VAS monitors the operating mode of its member VAV boxes, which are also members of an Area, but it does not control them. The VAS only controls its member VAV boxes that are designated as common space VAV boxes, VAV boxes or exhaust fans designated as ventilation members, and its member VAV AHU.

Important: In a VAS, the operating mode of common space VAV boxes are only controlled by the VAS. The operating mode of all other VAV boxes are controlled by the Areas they serve. If a VAV box has been designated as a common space VAV box, its operating mode cannot be controlled by an Area.

Area and VAS coordinate and control the operating modes of their members in the sequence described below:

1. Area(s) controls the operating mode of its VAV box members.

2. The VAS detects the change in operating mode of the VAV boxes that are members of the VAS.

3. The VAS evaluates the operating mode of each non-common space VAV box.

Figure 30. VAS and Area have mutual VAV members

Area:AAA Moving


Members of bothArea and VAS

VAV VAVVAV VAV

EF

VAV

Common SpaceVAVs

RTU 01 VAS

RTU 01

VAV AHU =






VAV System Overview

4. The AHU Mode Request of the VAS is determined based on the operating mode of the VAV box with the highest rank (lowest number)(refer to Table 8).

5. The VAS controls the AHU and common space VAV boxes to the same operating mode as follows:

Start up (fan on)

• The VAS System Mode transitions from Off to StartupDelay.

• The operating mode of the common space VAV boxes are immediately controlled to match the VAS “Common Space VAV Mode Request” property.

• The current value of the Startup Delay Time Remaining indicates the time left before the System Mode transitions to On.

• The AHU operating mode does not change until after the Startup Time Delay expires. It is then controlled to match the VAS “AHU Mode Request” property.

Shut down (fan off)

• The VAS System Mode transitions from On to ShutdownDelay.

• The operating mode of the air handler is immediately controlled to match the VAS “AHU Mode Request” property.

• The current value of the Shutdown Delay Time Remaining indicates the time left before the System Mode transitions to Off.

• The common space VAV boxes’ operating mode do not change until after the shutdown time delay expires. They are then controlled to match the VAS “Common Space VAV Mode Request” property.

Important: When multiple Areas exist, it is possible to have VAV boxes in the same VAS with different operating modes. When this occurs, the desired AHU mode of the VAS is determined as shown in Table 8 (Occupied having the highest rank and Unoccupied having the lowest rank)

Example: Figure 31, p. 68 shows that AAA Moving is in the Unoccupied mode and Eastside Law Offices is in the Unoccupied Heat/Cool mode. The VAV members of each Area are controlled to the corresponding operating mode.

The VAS evaluates which non-common space VAV member operating mode has the highest rank and uses that to determine its operating mode. In turn, the VAS controls the operating mode of the common space VAV boxes to match the VAS “VAV Mode Request” property. The AHU operating mode does not change until after the Startup Time Delay expires. It is then controlled to match the VAS “AHU Mode Request” property.

Table 8. VAS AHU Mode Request decision

RankNon-Common Space VAV Operating

Mode AHU Mode Request

1 Occupied Occupied

2 Optimal Stop Optimal Stop

3 Optimal Start Optimal Start

4 Humidity Pulldown Humidity Pulldown

5 Unoccupied Heating/Cooling Unoccupied Heating/Cooling

6 Unoccupied Dehumidification Unoccupied Dehumidification

7 Unoccupied Humidification Unoccupied Humidification

8 Night Purge Night Purge

9 Unoccupied Unoccupied



VAV System Overview

Note: The operating mode of the common space VAV boxes and the AHU mimic the operating mode of the non-common space VAV boxes with the highest ranking operating mode.

How Schedule and Area Determine Operating Mode

Integrating Area control with an HVAC Schedule enables Tracer SC to control the operating mode of the HVAC equipment based on time and temperature. This is why Areas are typically members of Schedules. Consider the following scenario for the building we discussed earlier.

Example: The two tenants operate on the following schedule:

Time-Based Only

If the HVAC equipment is controlled using a schedule without an Area defined, the occupancy of the equipment could only be controlled to Occupied between the hours of 6:30 AM and 5:00 PM and Unoccupied at all other times.

Figure 31. Example: VAS determining operating mode

Area:AAA Moving

Unoccupied

Unoccupied

Unoccupied Heating/Cooling


Unoccupied Heating/CoolingAHU Mode Request =

VAV Mode Request =

(Fan On)


Off

Area: Eastside Law Offices

Operating mode of VAV boxescontrolled to


Operating mode of VAV boxes

controlled to Unoccupied

VAV

EF

VAVVAV VAVVAV

Common SpaceVAVs

RTU 01 VAS

RTU 01


Table 9. 1st Street Office Building operating hours

Department Hours Days

AAA Moving 8 am to 5 pm M-F

Eastside Law Offices 6:30 am to 3:30 pm M-F



VAV System Overview

Temperature-Based

By using both an HVAC Schedule (time-based) and an Area (temperature), the operating mode of the equipment can be controlled to Optimal Start, Optimal Stop, Night Purge, and Unoccupied Heating/Cooling in addition to Occupied and Unoccupied.

• Optimal Start allows the equipment to start in advance of normal operating hours to ensure the space temperature is at the occupied temperature setpoint when employees arrive.

• Optimal Stop relaxes the occupied temperature setpoints up to two hours prior to the employees leaving as an energy saving measure.

• Unoccupied Heating/Cooling allows the equipment to start during unoccupied periods when the space temperature exceeds the unoccupied heating and cooling setpoints.

• During Unoccupied periods, Night Purge allows a warm interior space to be purged with cool, dry outdoor air during Unoccupied hours to cool the space prior to building occupancy.

Figure 32. Scheduled occupancy (time-based only—no Area)

Figure 33. Temperature-based control

6:30 AM

AM

5:00 PM

OccupiedUnoccupied

PM

Occupied Unoccupied

12

9 3

12

9 3

6:30 AM

4:30 AM

1:00 AM

3:00 AM

AM5:00 PM

PM

Occupied

OptimalStartOptimalStart

NightPurge

UnoccupiedOptimalStop

12

9

12

9 3

= Unoccupied heating/cooling is possible

Occupied



VAV System Overview

Humidity-Based

Humidity Pulldown allows the equipment to start in advance of normal operating hours to ensure the space humidity is at the occupied humidity setpoint when employees arrive.

Unoccupied Dehumidification allows the dehumidification members to start during unoccupied periods when the space humidity rises above the unoccupied dehumidification setpoint.

Unoccupied Humidification allows the humidification members to start during unoccupied periods when the space humidity falls below the unoccupied humidification setpoint.

Figure 34. Humidity-based control

6:30 AM

4:30 AM

3

AM5:00 PM

PM

Occupied

OptimalStartHumidityPulldown

Occupied

Unoccupied

Unoccupied

12

9

12

9 3

= Unoccupied dehumidification/humidification is possible



VAV System Overview

Important: Schedules and Area work together to determine the operating mode of the Area VAV box members. Those same VAV boxes are also members of the VAS. VAS gets its operating mode from them and controls its own VAV box members, which, in turn, it passes to the VAV AHU member. Therefore, the Schedule and Area ultimately determine the VAV AHU operating mode.

How Area Determines the Operating Mode of the VAV Box

Each Area automatically controls the operating mode of its VAV box members. When the Area is Occupied or Unoccupied by a Schedule, the Area controls the operating mode of the VAV box members to Occupied or Unoccupied respectively. The special cases are Optimal Start, Optimal Stop, Humidity Pulldown, Unoccupied Heating/Cooling, Night Purge, Unoccupied Dehumidification, and Unoccupied Humidification. Refer to “Standard Operating Modes,” p. 118 for more information on these modes.

Figure 35. VAS, Area, and Schedule interaction

Time-basedControl

Flow of control(Sequence)

Area:AAA Moving


Schedule Schedule

VAV VAVVAV VAVVAV

Common SpaceVAVs

RTU 01

RTU 01 VAS

VAV AHU =


of que


Temperature-based and

Humidity-based Control

EF




Tracer SC Application Setup for Variable Air Systems

This section includes:• Installing variable volume air handlers and VAV boxes• Setting up Areas• Setting up the VAS• Setting up Schedules• Navigating through the VAS pages• Commissioning and checkout

Tracer SC Equipment Definitions

Every controller used in the VAS must be assigned as either a VAV box or Variable Air Volume Air Handler equipment type in Tracer SC.







Building Operator

BAS Technician

BAS Technician(s)

Service Technician

Install

Program

CommissionCommis

Operate

Optimize

Design

Maintain

Before installing devices in Tracer SC, name equipment appropriately while commissioning the equipment in the facility. For equipment on a LonTalk communication link, this is the location label, and for equipment installed on a BACnet communication link this is the object name.

Add a “0” to the sequential number assigned by Tracer SC so the VAV boxes sort in the proper order (e.g., VAV 01-01, VAV 01-02, VAV 01-03, etc.)

Adding the type of space the VAV box serves to the object name, may be useful when selecting common space VAV boxes in the VAS or assigning VAV members to Areas.

Examples: VAV 01-01 (Room 212), VAV 01-02 (Cafeteria), etc.

BestPractice




Install and Set Up the Variable Air Volume Equipment Types

Follow the steps below to create and map equipment to devices on the Tracer SC.

1. Select Installation from the left-hand navigation.2. In the Configure Basic Settings for This Tracer SC frame, click Device Discovery (Figure 36).

The Discover Devices page appears.

3. Select the appropriate communication link to discover devices.

Note: BACnet links must be enabled under Identification and Communication > BACnet Configuration.

4. Click start discovery (Figure 37).

Figure 36. Device Discovery

Figure 37. Start Discovery




5. When the discovery status changes from “Discovery in Progress” to “Discovery Completed”, click install devices. The Install Devices page appears.

6. Select the check box for each piece of equipment to be installed and click install selected devices (Figure 38, p. 74). The Device Installation Complete page appears.

7. Confirm that the selected devices are installed.

Figure 38. Install Selected Devices




Set Up Areas

Areas play a vital role in VAV air systems, so it is very important they are set up correctly. Standard operating modes that rely on Area include Optimal Start/Stop, Unoccupied Heating/Cooling, and Night Purge. Refer to “Standard Operating Modes,” p. 118 for detailed information.

The basic steps for setting up an Area include:

1. Determine how many Areas are needed. (It is acceptable to have multiple Areas within a single VAS. Refer to “Defining Areas and Selecting Area Members,” p. 62.)

2. Determine which VAV boxes go with which Area (refer to “Defining Areas and Selecting Area Members,” p. 62).

3. Click create area on the Areas list page (refer to Figure 39).

4. Assign VAV boxes as Area members (“Select Members,” p. 77).

Note: Common space VAV boxes can be members of a Tracer SC Area. Making them a member of an Area allows Area to use the VAV boxes for functions such as average temperature calculation, timed override initiator, etc.

5. Reference temperature and humidity sensors to the Area (“Area Optimization,” p. 84).6. Configure Area functions such as Economizing, Night Purge, and humidity control strategies.7. Save the Area object. (“Create VAS Wizard,” p. 94).

Create Area Wizard: Determine the Areas

Create Areas

Before assigning VAV boxes to Areas, determine how the VAS will be divided. Usually, Areas are dictated by logical divisions: floors, walls, tenants, etc. (refer to Figure 40, p. 76)

1. Name the Area (for example, “AAA moving” is used here).2. Type a description of the Area (this is optional). Use this to help operators and technicians

determine which Area they are working on by location or the air handler serving the Area.3. If Economizing will be used, select the Supports Economizing Decision check box. Select

the appropriate economizing decision that Area will perform under the right circumstances.

Figure 39. Areas list page




Note: The drop-down list box contains seven possible choices for the economizing decision. When an option is selected, a description of that choice appears in the Description box to the right.

4. If Night Purge will be used, select the Supports Night Purge check box.5. If any of the three humidity functions will be used, select the Supports Humidity Control and

the appropriate humidity function.6. Click next.

Important: If you do not select a check box to support the Economizing Decision, Night Purge, or Humidity Control, the setup for these functions will not be included in the wizard. Additionally, those functions will be disabled within the Area you are creating. They can be enabled at a later time if desired.

Note: The reverse is also true. If a function is enabled on this page of the wizard, you cannot disable it on the Functions page of the wizard. You must either come back to this page of the wizard and change the check box for the function, or wait until the wizard is complete and then turn off the function on the Area Configuration page.

Figure 40. Create New Area - Define Area




Select Members

This page of the wizard allows you to select the equipment to be members of the Area you defined on page one.

1. From the selection tree, click the appropriate link to view the available items of that type. When the link is selected, all the available items of that type are presented in the available items column. Use the check boxes to select the items you want to include in the Area as members (refer to Figure 41, p. 77).

Important: VAV boxes, fan coil units, and water source heat pumps, appear under the spaces link in the selection tree. Constant volume air handlers, variable volume air handlers, and programmable controllers, appear under the equipment link in the selection tree.

2. Click Add. The items move to the selected items column on the right.3. Click next.

Figure 41. Create New Area - Select Members




Assign Member Types

This page of the wizard allows you to define what type of member is being added to the Area.

1. The Assign Member Types page appears with the items you selected on the previous wizard page (Figure 42). By default, all of these members are defined as Heating/Cooling members. In some cases, you will want to change an item from Heating/Cooling member to a Cooling, Heating, or Ventilation member. Use the list box behind each item to change its type designation. To change multiple items at the same time, select the check box in front of each item and use the actions... button to change the member type designation.

2. Click next.

Important: Common space VAV boxes can be assigned as members of an Area. These VAV boxes are still controlled by VAS. However, as members of the Area, they can initiate Timed Overrides and are included in Area temperature calculations.

Figure 42. Assign Member Types page

Leave most members as Heating/Cooling type members. Heating only and Cooling only members are typically used for testing.Best

Practice




Configure Members

When this page of the wizard appears (refer to Figure 43), some of the check boxes will already be selected based on the choices you made on the first page of the wizard. For instance, if you selected the Supports Night Purge check box on the first page, all of the members will be selected here as night purge members. This page is dynamic and changes based on your selections earlier in the wizard.

Note: If you do not select a check box on page one (i.e., Supports Humidity Control), none of the associated check boxes on this page of the wizard will appear (i.e., humidify or dehumidify).

The calculation check box indicates that the member (typically a VAV box) is included in the calculations conducted by Area for Average Space Temperature, Average Min Space Temperature, and Average Max Space Temperature. To exclude a member from Area calculations, deselect the check box in this column (e.g., if a VAV box is located in a closet or utility room, it is undersized, it may have a faulty space temperature sensor, etc., you may not want its input included in temperature calculations for the rest of the space).

Configuration

The important task on this page of the wizard (refer to Figure 44, p. 80) is to reference the temperature and humidity sensors for the Area. If the Area does not support humidity control (determined by the check box on the first page of the wizard), then only the space temperature sensor and the outdoor air temperature sensor need to be referenced.

Important: If the proper references to sensors are not set here, temperature and humidity control strategies (i.e., Optimal Start, Optimal Stop, Night Heat/Cool, Humidity Pull-down, etc.) will not work properly. Area will use constant values instead of the dynamic data obtained from the sensors, which accurately reflects current conditions.

Figure 43. Configure Member page




Setup:3. Click on the blue referencer icon ( ) behind the sensor value you want to reference.4. The Reference window appears. Choose either the User pre-defined data source or Select

custom data source options from the Change Data Source frame.

Note: The concept of a pre-defined referencer is new in Tracer SC. The pre-defined data source is typically the sensor or value that is used most often for the referencer. The only sensor that does not have pre-defined referencers defined is the space humidity sensor. The pre-defined defaults for each of the other sensors are listed below:

– Space temperature sensor = Area average space temperature (Area minimum space temperature and maximum space temperature are also available for selection)

– Outdoor air humidity sensor = Facility outdoor air humidity

– Outdoor air temperature sensor = Facility outdoor air temperature

5. Verify that the selections in the Event Notifications frame for Timed Override Class and Diagnostics Class meet the event routing needs for the facility.

6. Click Next.

Use the user pre-defined data source when possible.Best

Practice

Figure 44. Configuration page




Functions

The content of the Functions page depends on the selections you made on the Define Area page of the wizard. If you determined that the Area would support Economizing Decision, Night Purge, and Humidity Control, this page contains setup information that is critical to the proper operation of those functions in the Area application (Figure 45). If the Area does not support any of those functions, the Functions page will not appear in the wizard.

Figure 45. Function page




Functions - Economizing

This is a new function for the Area application. Area now has the ability to determine when to allow Economizing. Area then controls the Economizer Enable point to Enabled or Disabled (it does not actually control equipment). The Night Purge function can use this economizing decision for input on its decision to perform Night Purge.

The economizing decision is based on the type of Economizing selected on the first page of the wizard (refer to the bulleted list below) and the setpoints entered in the Start Condition and Stop Condition fields on this page of the wizard (referencers can be used for these values, but these are typically constants).

A box to the right of the condition fields explains how the economizing decision is made: • Fixed Dry Bulb — The ”Economizer Enable” point will be Enabled when the outdoor air

temperature falls below the start condition. This point will be Disabled when the outdoor air temperature rises above the stop condition.

• Differential Dry Bulb — The ”Economizer Enable” point will be Enabled whenever the differential between the outdoor air temperature and space temperature is below the start condition. This point will be Disabled when the differential between the outdoor air temperature and space temperature is below the stop condition.

• Fixed Enthalpy — The ”Economizer Enable” point will be Enabled whenever the outdoor air enthalpy is below the start condition. This point will be Disabled when the outdoor air enthalpy rises above the stop condition.

• Differential Enthalpy — The ”Economizer Enable” point will be Enabled whenever the differential between the outdoor air enthalpy and space enthalpy is below the start condition. This point will be Disabled when the differential between the outdoor air temperature and space temperature is below the stop condition.

Important: If Area is making an economizing decision based on enthalpy, the corresponding temperature and humidity sensors must be referenced. Area uses the space temperature and space humidity to calculate space enthalpy; and outdoor air temperature and outdoor air humidity to calculate the outdoor air enthalpy and dew point.

• OA Dew Point and OA Temperature — The “Economizer Enable” point will be Enabled when the outdoor air temperature is below the start condition and the outdoor air dew point is below the start condition 2. This point will be Disabled when either the outdoor air temperature falls below the stop condition or the outdoor air dew point rises above the stop condition 2.

• Referenced — The ”Economizer Enable” point will follow the referenced point status.

Example: TAn Area is being served by four rooftop units. The Area is configured to support the Economizing Decision using Fixed Enthalpy calculations. Using a referencer, each of the rooftop units can be configured to base its decision to economize on the condition of the Economizer Enable point in Area.

Setup

1. Support for economizing and the type of economizing decision have already been selected on the Define Area page of the wizard.

2. Type in a value for the Start Condition. This value will vary depending on how Area is making its economizing decision.

3. Type in a value for the Stop Condition. This value will vary depending on how Area is making its economizing decision.

4. Click Next.

Functions - Night Purge

The Night Purge function and its setup are described in detail in the Standard Operating Modes section (refer to “Night Purge (Night Economizing),” p. 129). Make the appropriate changes and click Next.




Functions - Humidity Control

The Humidity Control functions and their setup are described in detail Standard Operating Modes section (refer to “Humidity Pull Down,” p. 125, “Unoccupied Humidification,” p. 132, and “Unoccupied Dehumidification,” p. 133). Make the appropriate changes and click Next.

Confirmation

The confirmation page is a summary of all the settings you defined in the wizard and allows you to verify that they are as you expected them to be (refer to Figure 46).5. To change any of the parameters, click the previous until you come to the page of the wizard

that allows you to change the parameter.6. To confirm the settings for the Area and close the wizard, click finish.

Figure 46. Confirmation page




Area Optimization

After completing the wizard, optimize the Area to suit the needs of the facility. This includes defining the setpoints and offsets, Unoccupied operations, Optimal Start/Stop operation, Binary member operation, Setpoint Differentials, and Timed Override parameters.

Viewing an Area

Once you have created an Area with the wizard, view it to confirm your settings and make additional changes. To view all Areas created on the Tracer SC:

1. Select systems > areas from the left-hand navigation. The Area list page appears. 2. Click on the Area you just created with the wizard, or click the check box and select view from

the actions list. The Status page for the Area you selected appears.3. There are four pages associated with Area; they are: Status, Configuration, Functions, and

Members. When first entering Area, you see the Status page.

• The Status page displays general information about the Area, such as the current conditions in the Area (i.e., temperature, humidity, setpoints, etc.), its occupancy, what its members are doing, what functions are enabled, data logs, alarms and diagnostics, and who is controlling the Area

• The Configuration page displays information about the the Area setup (name, sensor values and references, heat/cool request, etc.), the Area operation (Unoccupied operation, Optimal Start/Stop operation, Timed Override operation, etc.), and Event Notifications

• The Functions page allows you to manage the Economizing, Night Purge, and Humidity Control functions

• The Member page allows you to add and delete equipment and points as members of the Area and modify their attributes

Application Defaults

Application defaults are a set of parameters that can be defined once and then used each time a new Area or VAS are created. You can change the defaults on your system permanently if you prefer different values than those originally created for the program. You can use the same capability to push changes to the parameters for existing Areas and VASs in a facility.

Viewing and Changing Application Defaults

To view and change the application defaults:

1. Select installation from the left-hand navigation. The Installation page appears. 2. Within the 2. Configure Facility Settings section, click on Application Defaults. The

Application Defaults page appears. 3. The page contains three sections: Alarming, Facility Defaults for Areas (Figure 47), and Facility

Defaults for Variable Air Systems. To change any of these parameters, click edit in the appropriate section. The parameters in the section become editable.




4. When finished making changes, click save.

Note: Not all of the parameters for an Area or VAS are available in the Applications Defaults. However, many of the common setpoints, deadbands, and differentials are there. A full set of parameters is available on the Area and VAS pages (status, configure, functions, and members).

Updating Existing Areas or VAS with New Defaults

Tracer SC allows you to push changes to these default settings to all existing Areas or Variable Air Systems in the facility. To update an existing Area or VAS with new defaults:

1. Click update all existing areas (or update all existing Variable Air Systems) at the bottom of the section. A warning box appears (Figure 48).

2. Click update.

Important: When you click update, ALL existing Areas or Variable Air Systems are updated with the new defaults.

3.

Figure 47. Facility Defaults for Areas

Figure 48. Update Confirmation




Area Setpoints

Setpoints are not set up in the wizard so they have to be managed after the Area wizard is complete. Area control uses six space temperature setpoints:• Occupied Cooling• Occupied Heating• Standby Cooling (used for Optimal Stop)• Standby Heating (used for Optimal Stop)• Unoccupied Cooling• Unoccupied Heating

Tracer SC calculates the Occupied and Standby Heating/Cooling setpoints using a single space temperature setpoint with offsets. The operator has five values they need to define (refer to Figure 49, p. 87) to make this strategy work properly, they are: Space Temperature Setpoint, Standby Offset, Occupied Offset, Unoccupied Cooling, and Unoccupied Heating. The unoccupied setpoints are not calculated, they are the absolute minimum and maximum temperatures that Area must try to achieve during unoccupied times.

Example: Area calculates the active setpoint based on the space temperature, the occupancy of the Area, and the current heating/cooling mode of the Area. For this example the Area is Occupied and in the Heating mode, the Space Temperature Setpoint is 72°F (22.2°C), and the Occupied Offset is 2°F (1.1°C). So the Occupied Heating setpoint is 70°F (22.2°C).

Area calculates the Occupied Heating setpoint by subtracting the Occupied Offset from the Space Temperature Setpoint (72°F – 2°F = 70°F)(22.2°C – 1.1°C = 21.1°C), and Occupied Cooling setpoint by adding the Occupied Offset to the Space Temperature Setpoint (72°F + 2°F = 74°F)(22.2°C + 1.1°C = 23.3°C).

Note: The Standby Cooling and Heating setpoints work the same as described above except that the Standby Offset is used instead.

The Unoccupied Cooling and Heating setpoints are not calculated by Area. The values typed into the fields (refer to Figure 49, p. 87) or referenced from another source are used as the setpoints.

All the equipment in a Tracer SC system also uses this same setpoint strategy, which allows Tracer SC to send a single space temperature setpoint from Area to the equipment and the equipment then calculates the heating and cooling setpoints based on the offsets defined for them.

Setup

1. Select systems > areas from the left-hand navigation.2. Click on the Area that you just created in the wizard, or the Area you want to modify.

Note: You can also click the check box in front of the Area and select view from the actions button list.

3. Review the space temperature setpoint, offsets, and unoccupied heating and cooling setpoints of the Area. The default values provided are adequate for most applications.

4. To change any of the setpoints or offsets, click edit.5. The setpoint and offset values become editable (Figure 49, p. 87). After making changes, click

save.

Calculated using a single space temperature setpoint and the occupied and standby offsets




Controlling Setpoints

Figure 50 shows the three ways a setpoint can be controlled:

1. By directly entering a value in the field.2. By overriding the setpoint directly with a static value.3. By selecting a referencer that will control the point at the priority level of the Area.

Note: When you change the setpoint by directly entering a value in the field, you are actually changing the default value for that setpoint.

Notice that not all the setpoints are editable directly (in this case only the Unoccupied Heating Setpoint and the Unoccupied Cooling Setpoint). The other setpoints have a referencer ( ) or an override ( ) available. The ability to override a point is prevalent throughout the Tracer SC system. Referencers, however, are unique to the Area application.Clicking on the override icon ( ) allows you to override the value of a point or an existing point override.This is a simple override. Refer to the Tracer SC online help for an in-depth discussion on overrides. You must have edit access to Area to perform advanced

Figure 49. Area Setpoint Status in Edit Mode

Figure 50. Controlling Setpoints




overrides on points created by the Area application. Advanced overrides allow you to override point values at various priority levels. To access the advanced override screen:

4. Click the override icon ( ) in the actions column to the right of the point you want to override. The Override page appears.

5. If you have the proper access, the more options button is available at the bottom of the section. Click more options. A more extensive Override Value section appears along with a Priority Array section (Figure 51). The Priority Array section shows who is currently controlling the point and a short list of what has controlled or requested control of the point in the past. The Override Value section allows you override the point at different priority levels. You will only be able to control a point at priority levels defined by your user profile.

6. Set the override as required and click apply.

Figure 51 also shows the priority array and user (user, referencer, or function) trying to control the Space Temperature Setpoint. The figure shows that the user named “Trane” tried to perform a simple override to control the point at priority level 13. Because Area is controlling the point at a higher priority level, user Trane had to perform an advanced override at a higher priority level than Area to override the point to the desired temperature.

Figure 51. Overrides and priority arrays




Synchronize Setpoints

The Tracer SC allows you to quickly send the five Area default setpoints to all the members of the Area with one action. The setpoints involved are the Space Temperature Setpoint, Standby Offset, Occupied Offset, Unoccupied Cooling, and Unoccupied Heating setpoints. To synchronize the setpoints:

1. Click actions... from the Status section of the Area Status page.2. Select synchronize all from the list.

This is not a selective process at this time. Synchronizing the setpoints pushes ALL the default setpoints (5 total) to EVERY member of the Area. If any of these setpoints has an override applied, at the member level, the override will remain in place. However, the default of the unit will be changed to match the synchronized value. When the override ends, the member will use the default value synchronized during this process.

Area Configuration—Setup

Heat/Cool Request

The Heat/Cool Request for Area is typically configured as Auto. This means that Area uses the Space Temperature Setpoint and the Occupied Cooling and Occupied Heating setpoints plus and minus 1°F (0.56°C) to determine whether to request Cooling or Heating. Other options are to use a referencer, or one of the other selections available in the drop-down list box.

Example: Area monitors the space temperature. When it rises to 1°F (0.56°C) above the Occupied Cooling setpoint, Area requests cooling. When the space temperature falls to 1°F (0.56°C) below the Occupied Heating setpoint, Area requests heating.

If you select the arrow on the list box, there are many options available for defining the Heat Cool Request (Optimal Cooling, Economizing, etc.). Regardless of which is selected, Area evaluates the option and decides which of these to implement: heating, cooling, or auto. For instance, if Optimal Cooling is selected as the Heat Cool Request option, Area sends that request to its members during Optimal Start; however, it is still a cooling decision. Therefore, the Area active heat/cool status is Cooling (refer to Table 10, p. 90).

Leave the Heat Cool Request set to Auto in the Area Configuration Setup section.Best

Practice

Figure 52. Area Configuration Setup




Area Configuration—Operations

Figure 53 shows the operations that can be Enabled and Disabled in the Operations section.

Unoccupied Operations

Enable this operation if you want Area to heat or cool during unoccupied periods. If Enabled, you can also set the differential value that defines how far below the Unoccupied Cooling setpoint the temperature must fall before Area stops cooling, and how far above the Unoccupied Heating setpoint the temperature must rise before Area stops heating.

Table 10. Area response to Heating Cooling Mode Request

Heating Cooling Mode Request Area Response

Auto Area makes Heating or cooling decision based on space temperature and occupied cooling and heating setpoint

Heat Heating

Optimal Heating Heating

Cooling Cooling

Night Purge Cooling

Optimal Cooling Cooling

Off Auto

Test Auto

Emergency Heat Heating

Fan Only Auto

Economizing Cooling

Ice Making Auto

Max Heat Heating

Economy Auto

Dehumidify Auto

Calibrate Auto

Figure 53. Area Configuration Operations




Optimal Start/Stop

This allows you to Enable or Disable Outdoor Air Temperature Compensation in the Area thermal ramp rate calculation. If Enabled, Area correlates the Optimal Start/Stop rates with the outdoor air temperature and adjusts the start/stop times if a drastic temperature change occurs from one day to the next.

Timed Override

If you want people in the building to be able to request a timed override, this operation must be Enabled. Timed Override is typically initiated from a zone temperature sensor in the space, which has an override button. This zone temperature sensor must be attached to a VAV box that is a member of the Area and is also defined as an override member on the Member Configuration page. You can set the duration for any overrides in this section as well. You can also use an Optional Input to initiate timed override when there is no zone temperature sensor available. The Optional Input is a multi-state value where 1 = TOV Auto, 2 = TOV On, 3 = TOV Cancel.

Binary Members

Binary members are non-equipment members of an Area. Therefore, Area can only control binary outputs or binary value points On or Off.

Binary Control-Continuous Operation

If the binary control is set for Continuous, Area controls the binary output to On any time the Area Heating/Cooling mode matches the binary member type (heating, cooling, or heating/cooling) and the Area is in the Occupied operating mode.

Binary Control-Cycling Operation

For Cooling only binary members, Area controls the binary member to On any time the space temperature rises above the Occupied Cooling Setpoint, the Heating/Cooling mode is Cooling, and the Area is in the Occupied operating mode. Area controls the binary member to Off any time the space temperature falls below the Occupied Cooling Setpoint minus the Binary Control Differential, or the Area Heating/Cooling mode transitions to Heating, or the Area operating mode transitions to Unoccupied (refer to Figure 54).

Example: An exhaust fan in a warehouse is used to vent hot air during the summer.

For Heating only binary members, Area controls the binary member to On any time the Area space temperature falls below the Occupied Heating Setpoint, the Heating/Cooling mode is Heating, and the Area is in the Occupied operating mode. Area controls the binary member to Off any time the space temperature rises above the Occupied Heating Setpoint plus the Binary Control Differential, or the Area Heating/Cooling mode transitions to Cooling, or the Area operating mode transitions to Unoccupied (refer to Figure 55, p. 92).

Example: An unit heater in a warehouse is used to heat a space during the winter.

Heating/Cooling binary members operate as a composite of both the heating only and cooling only operation (refer to Figure 56, p. 93)

Example: A third-party air handler is part of the system where Tracer SC only controls the Start/Stop status.




Figure 54. Cycling operation (with differential) for a binary cooling-only member

Figure 55. Cycling operation (with differential) for a binary heating-only member




Figure 56. Cycling operation (with differential) for a binary heating/cooling member




Occupied Setpoint Differential

You can only Enable or Disable this operation. If Enabled, an additional rule on the Setpoint Validation page is enforced. This rule follows ASHRAE standard 90.1, which states that half of the differential between the Occupied Heating and Cooling setpoints is the value of the Occupied Offset. So the Occupied Offset value can never be less than half the value of the Occupied Setpoint Differential if this function is enabled.

Create VAS Wizard

Creating a new VAS using the wizard requires fewer decisions than creating a new Area. In a variable air system, all of the VAV boxes connected to an air handler are members of the VAS. A VAS can only contain one air handler as a member. Tracer SC now allows for control of ventilation members as part of the VAS.

Create a VAS

Before creating a VAS, determine whether the VAS you create needs to support any optimization strategies (i.e., duct static pressure optimization or ventilation optimization).

1. To create a new VAS, select Systems > VAS from the left-hand navigation, then click on + create variable air system on the list page (Figure 57).

2. The Create Variable Air System wizard launches.

Define VAS Configuration

1. Name the VAS (we’ll use “RTU-01 VAS” as an example)(Figure 58).2. Type a description of the VAS (this is optional). Use this to help operators and technicians

determine which VAS they are working on by location or the Areas being served by the VAS.

Figure 57. VAS list page (no members)




3. There are also three check boxes and three editable fields in the Configuration Settings group. Trane recommends leaving these in their default settings. These are available after the VAS is created if you need to make changes.

4. If you are implementing Duct Static Pressure Optimization, select the Duct Static Pressure Optimization check box in the Optimization Support section.

5. If you are implementing Ventilation Optimization, select the Ventilation Optimization check box in the Optimization Support section.

6. Click Next.

Important: Ventilation Optimization requires that the air handler is equipped with Traq dampers or outdoor air flow sensors.

Important: When commissioning VAV boxes, define the outdoor air requirements for each VAV box using the Rover service tool or Tracer TU. You can see the values for outdoor air requirements from Tracer SC, but they are not editable, so this must be configured at the VAV box. The calculated values for each VAV box are available on the schedule from the Design Engineer.

Leave the check boxes selected for Allow VAVs to use auxiliary heat at night, Send source temperature to VAV boxes, and Send drive max to VAV boxes.Best

Practice

Figure 58. VAS wizard: Define the VAS Configuration




Allow VAVs to Use Auxiliary Heat at Night

When the Allow VAVs to use auxiliary heat at night check box is checked, VAV boxes have full control over their auxiliary heat at night.

Unchecking this check box (Figure 58, p. 95) allows the VAS to disable aux heat when the VAS requests that the AHU be in one of these modes: • Unoccupied • Optimal Start • Night Purge • or Unoccupied Heating/Cooling

Air Handler Startup Delay

The VAS delays controlling the Operating Mode of the AHU member for the duration of the Air Handler Startup Delay. This delay allows the common space VAVs time to open their dampers preventing over-pressurization of the ductwork.

VAV Box Shutdown Delay

When the Operating Mode of the VAS changes to Unoccupied, the VAS maintains the Operating Mode of the common space VAV boxes for the duration of the VAV Box Shutdown Delay time. This allows the static pressure in the ductwork to dissipate before allowing the common space VAV boxes to close their dampers.

Uncheck the Allow VAVs to use auxiliary heat at night check box when:• there is a heat source in the AHU and no local heat source in the VAV boxes, or• the local heat source isn't being used

BestPractice

Use the default setting (2 minutes) unless the drive times of the VAV boxes exceeds 90 seconds. If the drive times of the VAV boxes are more than 90 seconds, increase the AHU Startup Delay time.

BestPractice




Add Air Handlers

The Tracer SC VAS only allows variable air volume equipment to be added to a VAS as an AHU member. To add an air handler:

Important: If adding an air handler that has an MP580/581 installed, the DAC profile must be enabled with the Rover service tool prior to installing it on the Tracer SC.

1. Navigate to variable volume in the selection tree (Figure 59).2. Select the appropriate air handler from the available item list.3. Click add >.4. Click Next.

Figure 59. VAS wizard: Add an AHU




Add VAV Boxes

Only VAV boxes may be added to the VAS as VAV members. A VAV box can be a VAV member of only one VAS. However, a VAV box, which is a VAV member of one VAS, may also be a ventilation member of another VAS in certain circumstances (refer to “Dedicated Ventilation Systems,” p. 181). To add VAV boxes:

Important: Add all VAV boxes (including common space VAV boxes) served by the air handler to the VAS as VAV members.

1. Navigate to VAV boxes in the selection tree (Figure 60).2. Select the appropriate VAV boxes from the available item list.3. Click add >.4. Click Next.

Figure 60. VAS wizard: Add VAV boxes




Configure VAV Boxes

After selecting the VAV boxes, the wizard allows you to configure them. This page is dynamic based on your selections earlier in the wizard, so if you did not select the Supports Duct Static Pressure Optimization or Supports Ventilation Optimization check boxes, those columns will not be available here.

When the calculation check box is selected, the member will be included when VAS calculates the averages for the minimum and maximum temperatures.

The common space check box identifies the VAV box as a common space VAV box, which means its occupancy is controlled by the VAS and not the Area. For more information on common space VAV boxes, refer to “Common Spaces,” p. 61.

Note: Keep in mind that number of common space VAV boxes should equal 20% of the total number of VAV boxes in the VAS.

To configure VAV boxes:

1. Select or unselect the check boxes following each VAV box in the selection list (Figure 60). Clicking the check box in the column head selects all the check boxes in the column.

2. Click Next.

Important: VAV boxes must be members of an Area for the VAS to see mode changes. VAS monitors the mode of the VAV boxes and uses that information to change and control the air handler.

Figure 61. VAS wizard: Configure Members




Add Ventilation Members

A ventilation member can be a VAV box, a binary output point, or a binary value point. An exhaust fan or a VAV box providing outdoor air to the air handler in a dedicated ventilation system are good examples of ventilation members. Ventilation members are turned on and off based on the operating mode of the VAS. When the VAS is in the Occupied or Optimal Stop mode, the ventilation members are On. During all other VAS modes, the ventilation members are Off.

Important: Ventilation members are controlled by VAS at the VAS priority level.

To add Ventilation members:

1. Navigate to VAV boxes in the selection tree (VAV boxes are located under spaces). You can also navigate to binary outputs and binary values under points to select those as ventilation members (Figure 60, p. 98).

2. Select the appropriate VAV boxes/binary outputs/binary values from the available item list.3. Click add >.4. Click Next.

Figure 62. VAS wizard: Add Ventilation Members




Set Up Functions

This page of the wizard (Figure 63, p. 102) only displays if one or both of the Supports Duct Static Pressure Optimization or Supports Ventilation Optimization check boxes are selected on the first page of the wizard. The initial values in each section are pulled from the application defaults (refer to “VAS Application Defaults,” p. 104). When these applications are enabled, the Tracer SC VAS calculates an optimized static pressure setpoint and an optimized minimum outdoor airflow setpoint.

Important: Further setup is required. Selecting the check boxes, enabling both optimization strategies, optimizes the setpoints but does not communicate them to the air handler. Refer to “Optimization,” p. 157 for more detailed setup information.

Duct Static Pressure Optimization

Typical values for the duct static pressure setpoints are:• Minimum Static Setpoint: 0.75 in(H20) (186.63 Pascal)• Startup Static Setpoint: 1.00 in(H20) (248.84 Pascal)• Maximum Static Setpoint: 1.50 in(H20) (373.26 Pascal)

Tracer SC offers a new feature for duct static pressure optimization. In previous products, the reset up and reset down functions had the same increment value and time interval for both directions. Now, reset up and reset down can be set independently from each other with different time intervals and increment values.

Ventilation Optimization

The ventilation optimization section requires only one change to allow the function to operate properly. The Startup Airflow Setpoint is zero, which is also the default, but the value must be changed to the design airflow value for the air handler. The air handler’s design airflow is available on the schedule/prints from the Design Engineer.

Important: When commissioning VAV boxes, define the outdoor air requirements for each VAV box using the Rover service tool or Tracer TU. You can see the values for outdoor air requirements from Tracer SC, but they are not editable, so this must be configured at the VAV box. The calculated values for each VAV box are available on the schedule from the Design Engineer.




Confirm Selections

The Confirm Selections page (refer to Figure 64, p. 103) allows you to see the settings you made and to go back and make changes if necessary. The group just above the cancel, previous, and finish buttons, shows which Tracer SC is the destination for the VAS (where it will be saved) when you click finish.

Figure 63. VAS wizard: Set Up Functions




Figure 64. VAS wizard: Confirmation




VAS Application Defaults

The application defaults for VAS are located on the same page as the application defaults for Area. Refer to “Application Defaults,” p. 84 for detailed information on Facility Defaults for Variable Air Systems (Figure 65).

Navigating Through the VAS Pages

After the VAS is set up using the wizards, as described earlier in this section, you can revisit any of the parameters configured in the wizard by navigating to the VAS pages in the Tracer SC.

Status Page

The VAS Status page is the first page to appear and provides detailed information for the selected VAS. Each section on this page can be collapsed or expanded to view the contents by clicking the arrow in the left most corner.

Access

From the Variable Air Systems page click on the name of the VAS you created in the wizard, or select a VAS from the list and then select view from the actions button.

Content

The Status page appears by default; however, you can access the following pages for the VAS by clicking the appropriate button at the top of the Status page.• configure — Click to open the Configuration page for this VAS• functions — Click to open the Functions page for this VAS• members — Click to open the Members page for this VAS

Alarms and Diagnostics Section

This section contains a table that shows unacknowledged alarms for the area. Click on an alarm type to open the Alarm and Event log.

More values — Click to open a list containing more VAS properties and current values.

Figure 65. Facility Defaults for VAS




Status Section. This section shows the conditions, current value, and status of the VAS. All values within the table can be selected to create a data log. • actions — Click this button to create data logs for the selected values • more values — Click to open a list containing more VAS properties and current values

Functions and Calculations Section

Functions Table

The Functions table shows features that have been selected for the VAS and whether they are currently enabled or disabled. See the VAS Configuration and VAS Functions pages for function definitions.

Calculations Table

The Calculations table shows the current status of the calculated values for the VAS. To create data logs, use the check boxes to select calculations and then select log selected data from the actions button.

Members Section

This section contains status details for air handlers, VAV Boxes, and ventilation members, each divided into separate tables. Each table shows the name of the VAS member and related status details.

Graph Section

This section displays data logs that were automatically generated when the VAS was initially created.

Configuration Page

The VAS Configuration page shows the configuration settings for the selected VAS. This is an editable page in which you can make changes to most of the current configurations. The page is divided into two sections — Setup and Operations.

Access

Click configure from the Variable Air System Status page, the Variable Air System Functions page, or the Variable Air System Members page.

Content

The following pages for the VAS are available from the Configuration page by clicking the appropriate button at the top of the page.• status — Click to open the Status page for this VAS• functions — Click to open the Functions page for this VAS• members — Click to open the Members page for this VAS

Setup Section

This section shows basic settings for the VAS. To make changes, enter or select a value in the corresponding property fields.

Name — Shows the display name of the VAS.

Description — Shows a brief description of the VAS (optional).

Air Handler Startup Delay — This shows the amount of time in which the VAS will wait before starting the air handler unit.

VAV Box Shutdown Delay — This shows the time in which the VAS waits before shutting down common space VAV boxes after the VAS enters the unoccupied mode.




VAV AHU Startup Temperature — When the VAS operating mode transitions to Optimal Start, Unoccupied Heating/cooling, Unoccupied Humidify, Unoccupied Dehumidify, or Humidity Pulldown, it compares the VAS average space temperature to the AHU Startup temperature. If the average space temperature is warmer than the startup temperature, the VAS sends PreCool to the VAV AHU heat/cool request. If the average space temperature is below or equal to the startup temperature, the VAS sends Morning Warm-up to the VAV AHU heat/cool request.

Allow VAVs to use auxiliary heat at night — When unoccupied, which is typically at night, VAV boxes use local heat to heat the space. Use the check box to enable or disable this setting.

Send source temperature to VAV boxes — Select this option to send the AHU discharge air temperature to all VAV boxes.

Send drive max to VAV boxes — Select this option to drive all VAV boxes to maximum flow when the AHU enters a constant volume mode.

Operations Section

This section shows the calibration and autocommissioning status for the VAS.

Calibration

This box shows the current calibration status. You can enable or disable calibration and change the trigger value in this box. Refer to “VAV Calibration,” p. 116 for more information.

Autocommissioning

This box shows the current autocommissioning status. This is a defined operating sequence that validates the proper operation of all inputs and outputs of VAV members. You can enable or disable autocommissioning by clicking start/stop.

Important: cancel — Click to return to the previous page. Changes made on this page will not be saved.

save — Click to save your changes.

Functions Page

This page shows the current functions and associated values for this VAS. To make changes, enter new values and then click save.

Access

Click functions from the VAS Status page, the VAS Configuration page, or the VAS Members page.

Content

The following pages for the VAS are available from the Functions page by clicking the appropriate button at the top of the page.• status — Click to open the Status page for this VAS.• configure — Click to open the Configure page for this VAS. • members — Click to open the Members page for this VAS.


This function determines the optimal duct pressure based on VAV air-valve positions. This function reduces energy costs by ensuring that the air handler unit (AHU) is operating just enough to satisfy the most-open air valve. In this section you can select to enable or disable this function and enter or change values.

Currently — Shows whether this function is enabled or disabled.Minimum value — This is the minimum operating pressure.Startup value — The VAS uses this value if optimization is disabled and on startup. Maximum value — This is the maximum operating pressure allowed.




Reset Table Values

Enter values in following fields to determine when to raise or lower the static pressure setpoint.

increment — The amount that the static pressure can be raised or lowered for each interval.

interval — The point at which the static pressure setpoint is re-evaluated.

maximum air valve position — If the system static pressure causes an air valve position in the VAV boxes to exceed the maximum air value position setting, then the static press setpoint is adjusted either up or down by the values in the increment fields.

Status

This area contains status values for this function. Click refresh to update the values.

Ventilation Optimization Section

This function calculates the system outdoor air requirement based on real time conditions in spaces. This minimizes the amount of outdoor air that must be brought into the building. In this section you can select to enable or disable this function and enter or change values.

Currently — Shows whether this function is enabled or disabled.

Startup airflow setpoint — This is the value that the outdoor air setpoint sends to the AHU when the VAS transitions from an unoccupied mode to an occupied mode.

Maximum Outdoor Air AHU can condition — This is the maximum percentage of outdoor air that the AHU can deliver to the space.

VAV Maximum Percentage of Outdoor Air Request — This is the maximum allowed percentage of outdoor air that a VAV box can request. The VAS sends this value to the VAV box.

Reset Interval for Recalculation — This is the amount of time before the VAS will recalculate a new outdoor air flow setpoint.

Status

This area contains status values for this function. Click refresh to update the values.

Important: cancel — Click to return to the previous page. Changes made on this page will not be saved.

save — Click to save your changes.

Members Page

This page shows current members for the selected VAS. In addition, you can select to add more members.

Access

Click Members from the VAS Status page, the VAS Configuration page, or the VAS Functions page.




Content

The following pages for the VAS are available from the Functions page by clicking the appropriate button at the top of the page.• status — Click to open the Status page for this VAS• configure — Click to open the Configure page for this VAS• functions— Click to open the Functions page for this VAS

Air Handler Section

This section shows air handlers that are members of the this VAS and the current occupancy for each. • actions — Click or pause over this button to take action on a selected member• + Air Handler — Click to open the Add Air Handler Member page (only available is no AHU

members are selected)

VAV Box Section

This section shows VAV boxes that are members of this VAS and the current occupancy and status for each. • actions — Click or pause over this button to take action on a selected member• + add VAV box — Click to open the Add VAV Box Member page

Ventilation Section

This section shows ventilation members for this VAS and the current occupancy for each. • actions — Click or pause over this button to take action on a selected member• + Air Handler — Click to open the Add Air Handler Member page

Add the Area to an HVAC Schedule

Once Areas and the VAS are created, you need to create schedules and add the Area to an HVAC schedule. Tracer SC uses schedules that are BACnet compliant. Because of this, an individual schedule is required for each data type. Therefore, Tracer SC has four types of schedules:• HVAC schedules• Analog output schedules• Binary output schedules• Multi-state output schedules

HVAC Schedules

When scheduling Areas, and you want to use Optimal Start and Stop, use an HVAC schedule. HVAC schedules are actually multi-state schedules with some additional functionality built in for Optimal Start. You can use HVAC schedules for Trane equipment, but the equipment will not respond to the Optimal Start/Stop functions of the schedule. It is better to use a multi-state schedule for equipment.

An advantage to using HVAC schedules for Areas is that HVAC schedules use Trane’s implementation of occupancy, which is Occupied, Unoccupied, Standby, and Bypass. Whereas, multi-state schedules use actual values such as “1”, “2”, “3”, ...up to “20” instead of state text to designate the state of the device (per the BACnet standard).

Do not include equipment in HVAC schedules if you plan to use Optimal Start/Stop, because Optimal Start/Stop are functions of Area and typically only Areas are members of HVAC schedules.

BestPractice




In this Tracer SC Air Systems Applications Guide, we will only be using HVAC schedules. For more information on analog output, binary output, and multi-state schedules, refer to the Tracer SC online help.

Analog Output Schedules

Analog output schedules are comparable to the Set Analog function in Tracer Summit. Keep in mind that in Tracer Summit you can mix schedule types, where Tracer SC has BACnet compliant schedules, which must be kept separate by data type. When you want to schedule an analog output or an analog value to change, you can use an analog output schedule. Examples of when you might use an analog output schedule:• In a ventilation optimization scenario, you can schedule the outdoor air requirement airflow for

a space based on the expected occupancy. For instance if you know a classroom will be filled with 20 people between 1 PM and 3 PM, you can schedule the outdoor air airflow rate to change from 200 cfm to 400 cfm for that 2 hour duration. At 3 PM, after everyone has left the classroom, you can schedule the rate to return to 200 cfm.

• It is also useful for scheduling changes to setpoint values. For instance, if you want the chilled water temperature setpoint for your chiller plant at 40°F at 4 AM, and at 45°F at 10 AM, you could use an analog output schedule to accomplish to make those changes.

Binary Output Schedules

Binary output schedules allow you to schedule On/Off events for binary outputs and binary values. An example of when you might use a binary output schedule:• This is a useful schedule to control lighting. For instance, you can control binary outputs to

parking lot lights with a binary output schedule.• You can use a binary output schedule to control internal lighting in conjunction with HVAC

control. However, these are two different schedules in Tracer SC.

Multi-state Output Schedules

Multi-state output schedules are very similar to HVAC schedules and allow you to schedule multi-state outputs and values. However, a multi-state schedule does not have the capability to perform optimal start and stop functions. Each multi-state schedule contains 20 states. Each state is identified by number and has no state text associated with it. Use multi-state schedules to control equipment that does not require the optimal functions.




Create an HVAC Schedule with the Create Schedule Wizard

Once the Area is created, you need to create an HVAC schedule and add the Area to it as a member.

1. Select schedules from the left-hand navigation.2. The Active Schedules list page appears. Click Create schedule... (Figure 66)..

3. The Schedule Information page appears (Figure 67). Type in a name for the schedule.4. Select the HVAC schedule option and click the Optimal Start/Stop check box. 5. Click next.

Figure 66. Schedule list page

Figure 67. Create Schedule - Schedule Information




6. The Schedule Times page appears (Figure 68). The current date displays as the default Start Date in the Specify Effective Dates group. Choose the Start Date and End Date for your HVAC schedule.

7. Add the effective days and times for the schedule. Click + add event.8. The Add event -HVAC window appears (Figure 69). Select the check boxes for Start Time, Stop

Time, and the days of the week you want to schedule. Set the Start Time and Stop Time. Click add.

Figure 68. Create Schedule - Schedule Times

Figure 69. Create Schedule - Add Events




9. A vertical bar appears on each day you selected with the appropriate start and stop time (Figure 68, p. 111). Click + add optimal window.

10. The Add Optimal Window appears (Figure 70). Select the check boxes for Start Time, Stop Time, and the days of the week you want to schedule an optimal window. Set the Start Time and Stop Time. Click add.

11. A darker vertical bar representing the optimal window appears behind the event bar on each day with the appropriate start and stop times set (Figure 68, p. 111). Click next.

Important: The optimal window defines a period of time in which Optimal Start and Optimal Stop can occur if the conditions are right. It does not define exactly when the optimal events will start and stop. For detailed information on how Optimal Start and Optimal Stop operate, refer to “Optimal Start (PreCool/Morning Warm-up,” p. 122 and “Optimal Stop,” p. 127.

12. The Select Members page appears (Figure 71). Click on areas in the selection tree, highlight the Areas available in the available items column, and click add >.

Important: Areas can be member of more than one HVAC schedule. However, the effective dates and times of those schedules cannot overlap.

13. The appropriate Area moves to the selected items column. Click next.

Figure 70. Add Optimal Events




14. The Summary page appears. This page is a summary of all the settings you defined in the wizard and allows you to verify that they are as you expected them to be (refer to Figure 72, p. 114).

15. To change any of the parameters, click previous until you come to the page of the wizard that allows you to change the parameter.

16. To save the settings for the HVAC schedule and close the wizard, click finish.17. The Confirmation page appears (Figure 73, p. 115). This page shows you the created schedule

and confirms that it has been created successfully.

Figure 71. Wizard - Select Members




Figure 72. Wizard - Summary




Figure 73. Confirmation page




VAV Calibration

During a VAV calibration, the controller:

1. Closes the damper.2. Reads the voltage from the flow sensor at zero airflow.

To prevent duct over-pressurization, the SC divides the VAV boxes into 6 groups and staggers the command to calibrate between these six groups. A new group of VAV boxes calibrates every 15 minutes until finished.

3. Closes the water valve and zeros the valve position.4. When calibration is complete, the VAV box resumes normal operation.

Auto-Calibration

One of the features of the Tracer VV550/551 and UC400 VAV controllers is auto-calibration. Auto-calibration eliminates the need for scheduled calibration in most applications. A calibration sequence is initiated after either a power cycle, or when the operating mode of the VAV box transitions from Occupied to Unoccupied. Actual calibration of the VAV boxes begins after a fixed, 3-minute delay.

Initiating a Scheduled Calibration

As an alternate to auto-calibration, VAV boxes may be recalibrated by scheduling a binary output (BOP) object referenced to the VAV Calibration field in the VAS editor.

1. Create a binary output object in Tracer SC.2. Select Schedules... from the main menu.3. Add the binary output object as a member of a new or existing schedule.4. Schedule the BOP to ON (1-Recalibrate) for at least one minute.5. Schedule the BOP to OFF (0-Normal).6. Select VAV Air Systems > [specific system...] from the main menu. 7. On the Configure page, reference the binary output in the VAV Calibration field.

Manually Initiating an Unscheduled Calibration

Initiate an unscheduled calibration sequence from the VAS Configure page.

1. On the VAS Configure page, select the override icon for the calibration trigger. 2. The Override page appears, in the Override Value frame, 3. Change the Change Value To field to Recalibrate.

VAV boxes that are always Occupied (a hospital is a good example) can only be recalibrated by scheduling calibration.Best

Practice

Figure 74. Manually Initiating Calibration




4. Select the Allow the change to expire check box.5. Set the value to expire in 2 minutes.6. Click Save.

Commissioning and Checkout

For basic information about commissioning the system, refer to the Tracer VV550/551 VAV Controller Installation and Operation guide (CNT-SVX17A-EN) and the Installation Operation Manual Tracer UC400 Programmable BACnet Controller (VAV-SVX07A-EN).

Refer to “Commissioning,” p. 140 for additional information on commissioning the system after it has been set up.

Figure 75. Auto-commissioning Active Frame



Standard Operating Modes

This section explains the following standard operating modes:

• Unoccupied heating/cooling

• Optimal start (PreCool/Morning Warm-up)

• Humidity Pull Down

• Warm-up with normal start (no optimal start)

• Daytime Warm-up

• Optimal stop

• Night purge

• Unoccupied dehumidify

• Unoccupied humidify

• Timed override

• General Settings - Best Practices

Important: Most of the actions (i.e., scheduling, optimal start, unoccupied heat/cool, etc.) are initiated by the Area(s) containing the VAV boxes. The VAS monitors the VAV boxes and controls the air handler accordingly.

Important: For detailed information on how Area controls its members based on operating mode, refer to Table 19, p. 242

For the standard operating modes to work properly, the system must be set up in a specific way. For a summary of these settings and practices, refer to “General Settings,” p. 136. For detailed setup instructions refer to “Tracer SC Application Setup for Variable Air Systems,” p. 72”.


The easiest way to reduce heating and cooling energy consumption and cost during unoccupied periods is to expand the space temperature setpoints (sometimes referred to as night setback). Unoccupied Heating/Cooling allows the temperature in a conditioned space to fall/rise to the unoccupied setpoints before enabling the HVAC equipment.







Building Operator

S Technician

Service Technician

BAS Technician(s)

AAAS

Building Operator

B

Install

Program

CommissioCommis nn

Operate

OptimizeOptimizOptim

Design

Maintain




Implementing Unoccupied Heating/Cooling requires both the Scheduling and Area functions in Tracer SC.

1. On the Area page, set the unoccupied heating and cooling setpoints to temperature limits that will protect the building.

2. Create a schedule for each area (refer to “Add the Area to an HVAC Schedule,” p. 108).

3. Assign the areas as members of the appropriate HVAC schedule.

4. Unoccupy the areas by creating an HVAC schedule with an unoccupied event.

When Unoccupied Heating/Cooling begins, the area occupancy is controlled to Unoccupied by the HVAC schedule. In turn area controls the operating mode of the area members to unoccupied and, consequently, the VAS controls the operating mode of the air handler and common space VAV boxes to unoccupied.

While Unoccupied, the Area monitors the space temperature continuously. If the space temperature reaches the unoccupied heating setpoint (Unoccupied Heat) or the unoccupied cooling setpoint (Unoccupied Cool), the Area controls the operating mode of the VAV members to Unoccupied Heating/Cooling. The VAS then controls the operating mode of the air handler and common space VAV boxes to Unoccupied Heating/Cooling.

The operating mode of the VAV boxes remain in Unoccupied until the Area space temperature:

• Rises above the Unoccupied Heating setpoint plus the Unoccupied differential, or

• Falls below the Unoccupied Cooling setpoint minus the Unoccupied differential

Note: The Area occupancy remains Unoccupied until Scheduling controls it to Optimal Start or Occupied.

Unoccupied Heating

When an Area space temperature sensor value falls below the unoccupied heating setpoint (refer to Figure 76 note), the Area operating mode transitions to Unoccupied Heating/Cooling. The Area application controls the operating mode of each Heating Only, and Heating/Cooling VAV member to Unoccupied Heating/Cooling. VAS detects this transition, which causes the VAS operating mode transition to Unoccupied Heating/Cooling, which enables the VAV air handler. Ventilation members and Cooling Only members remain Unoccupied or Off.

Unoccupied heating stops when the Area's inside space temperature rises above the unoccupied heating setpoint plus the unoccupied differential (Area > Configuration page).

Area unoccupied cooling setpoint = 85°F (29.4°C)(default)

Area unoccupied heating setpoint:

• Unoccupied heating with central fan = 60°F (15.6°C)(default)

• Unoccupied heating without central fan = 40°F (4.4°C)(refer to Table 11, p. 120)

BestPractice

Use the default value for the unoccupied differential, which is 4.0°F (2.2°C).Best

Practice




Note: Area occupancy remains Unoccupied until an HVAC Schedule controls it to Optimal Start or Occupied.

Important: To disable the reheat in the VAV boxes when their operating mode is Unoccupied, Unoccupied Heating/Cooling, Night Purge, or Optimal Start, uncheck the Allow VAV Aux Heat at Night check box in the VAS editor (Setup tab) as shown in Table 11.

Figure 76. Unoccupied heat

is locked out

SpaceTemperature

64° F

Unoccupied HeatEnds

Unoccupied HeatStarts

60° F

UnoccupiedHeatingsetpoint

Unoccupied Differential

Table 11. Unoccupied heating scenarios and setup

Scenario Editor Settings Example

Heating with central heat only

Applies when it is most cost effective to heat the spaces using only the heat source in the air handler during unoccupied periods.

VAS editor (Setup tab)

Disable local heat.

Gas heat in the air handler and electric heat in the VAV boxes

The air handler is enabled and uses its heat to maintain the discharge air heating setpoint.

Local heat at the VAV boxes is disabled.




Heating with local heat and a central fanApplies when the air handler has no heat or insufficient heat, or the VAV boxes are equipped with reheat but have no fan.

The central fan is used to:• provide air flow allowing VAV

boxes to use their local heat.• circulate air between interior and

exterior zones to facilitate the warm-up process.

The VAV box controls local heat to its occupied setpoints when its mode is warm-up.

Area editorThe unoccupied heating setpoint of the Area is 60.0°F (15.6°C)

The unoccupied differential of the Area is 4.0°F (2.2°C).

VAV editorThe VAV box unoccupied heating setpoint should be less than the Area unoccupied heating setpoint (VAV editor, Configuration tab). This prevents the VAV box from using its local heat when its operating mode is unoccupied.

VAS editor (Setup tab)Enable local heat.

There is no heat in the AHU and shutoff VAV boxes with reheat. The central fan must run for heat.

Heating with local heat only (central fan not used during unoccupied heating)Applies when the air handler is not equipped with heat and the central fan will not be used during unoccu-pied heating.

The VAV box manages all the heat-ing during unoccupied periods by using its local heat and/or enabling its remote (perimeter) heat. The VAV boxes will remain in the unoc-cupied mode and use their unoccu-pied heating setpoints.

Note: A series or parallel fan is required if the heat is in the VAV box.

Area editorThe Area unoccupied heating setpoint (Setup tab) should be set to a very low value (e.g., 40°F (4.4°C)).

Note: Do this so the Area never controls the VAV boxes during unoccupied heating.

VAV editorThe unoccupied heating setpoint of the VAV box is 60.0°F (15.6°C).The unoccupied differential of the VAV box is +/- 1.5°F (0.9°C).• Local heat is enabled at 58.5°F (14.7°C)• Local heat is disabled at 61.5°F (16.4°C)

VAS editor (Setup tab)Enable local heat.

Parallel fan-powered VAV boxes with reheat located around the perimeter of the building.

Table 11. Unoccupied heating scenarios and setup





Unoccupied Cooling

When an Area space temperature sensor value rises above the unoccupied cooling setpoint (refer to Figure 77 note), the Area operating mode transitions to Unoccupied Heating/Cooling. The Area application controls the operating mode of each Cooling Only, and Heating/Cooling VAV member to Unoccupied Heating/Cooling. VAS detects this transition, which causes the VAS operating mode to transition to Unoccupied Heating/Cooling, which enables the VAV air handler. Ventilation members and Heating Only members remain Unoccupied or Off.

Unoccupied Cooling stops when the Area's inside space temperature falls below the unoccupied cooling setpoint minus the unoccupied differential (System > Area > Configuration page).

Note: The Area occupancy remains Unoccupied until Scheduling controls it to Optimal Start or Occupied.

Optimal Start (PreCool/Morning Warm-up

Optimal start is the process of the HVAC Schedule and Area functions working together to PreCool or warm-up a building prior to occupancy so the temperature is at or close to its occupied setpoints when the building becomes occupied.

Note: The air handler may keep the outdoor air damper closed during Optimal Start because it occurs during Unoccupied periods. The Area occupancy remains Unoccupied as dictated by the HVAC Schedule.

Cooling (Area is in the Cooling Mode)

1. Area determines the actual time to control the operating mode of VAV boxes to Optimal Start based on the Area inside space temperature, the occupied cooling setpoint, and the associated cooling optimal start rate.

2. When the calculated start time falls within the optimal window defined in the HVAC Schedule:

• The Area operating mode transitions to Optimal Start.

Use the default value for the unoccupied differential, which is 4.0°F (2.2°C).Best

Practice

Figure 77. Unoccupied Cooling

is locked out

SpaceTemperature

85° F

Unoccupied CoolingEnds

Unoccupied CoolingStarts

81° F

UnoccupiedCoolingsetpoint

Unoccupied Differential




• The Area operating mode for cooling only and heating/cooling members transitions to Optimal Start.

Example:

Initial space temperature = 79°F (26.1°C) Cooling Optimal Start rate = 8 min/°F (14.54min/°C)(learned by Area) Occupied start time = 8:00 AM Optimal Start window = 6:00 to 8:00 AM Occupied cooling setpoint = 75°F (23.9°C)

Area calculates the optimal start time as follows:

(79°F - 75°F) x 8 min/°F = 32 minutes

or

(26.1°C - 23.9°C) x 14.54 min/°C = 32 minutes

Heating (Area is in the Heating Mode)

1. Area determines the actual time to control the operating mode of VAV boxes to Optimal Start based on the inside space temperature, the occupied heating setpoint, and the associated heating optimal start rate.


• The Area operating mode transitions to Optimal Start

• The operating mode of the Area heating only and heating/cooling members transitions to Optimal Start

Example:

Initial space temperature = 65°F (18.3°C) Heating Optimal Start rate = 10 min/°F (17.85 min/°C)(learned by Area) Occupied start time = 8:00 AM Optimal Start window = 6:00 to 8:00 AM Occupied heating setpoint = 70°F (21.1°C)

Figure 78. Optimal start cooling (shown in °F)

is locked out

SpaceTemperature

InitialSpaceTemperature

79° F

Optimal StartEnds

CoolingBegins

75° F

8:00 AM

OccupiedUnoccupied

OccupiedCoolingsetpoint

Calculated Optimal Start Time

7:28 AM





(70°F - 65°F) x 10 min/°F = 50 minutes

or

(21.1°C - 18.3°C) x 17.85 min/°C = 50 minutes

Setup

Create an HVAC Schedule with an optimal window defined and an Area added as a member.

Figure 79. Optimal start heating (shown in °F)

is locked out

SpaceTemperature Initial

SpaceTemperature

70° F

Optimal StartEnds

HeatingBegins

65° F

8:00 AM

OccupiedUnoccupied

OccupiedHeatingsetpoint

Calculated Optimal Start Time

7:10 AM

Table 12. Optimal Start heating scenarios


Heating with central heat onlyApplies when it is most cost effec-tive to heat the spaces using only the heat source in the air handler.

Scheduling editorCreate an HVAC Schedule with an optimal window defined with an 8:00 AM start. Add the Area as a member of this schedule.VAS editor (Setup tab)Disable the local heat.

Gas heat in the air handler and electric heat in the VAV boxesArea initiates Optimal Start at 7:10 AMThe air handler is enabled and uses its heat to main-tain the discharge air heat-ing setpoint.Local heat at the VAV boxes is disabled.




Humidity Pull Down

Humidity Pull Down is the process of the HVAC Schedule and Area functions working together to reduce the humidity in a building prior to occupancy so the humidity is at or close to its occupied humidity setpoint when the building becomes occupied.

Note: The air handler may keep the outdoor air damper closed during Humidity Pull Down because it occurs during Unoccupied periods. The Area occupancy request remains Unoccupied by the HVAC Schedule; Area occupancy status transitions to Occupied.

To Set Up Humidity Pull Down:

Follow these steps to set up humidity pull down:

1. When configuring an Area, reference the space humidity sensor.

2. Enable Humidity Pull Down (Figure 80).

3. Enter an Occupied Humidity Setpoint (default is 50%).

4. Add Members to the Area with the dehumidification check box selected.

5. Create an HVAC Schedule with an optimal window and add the Area to the schedule as a member.

Heating with local heat and a central fanApplies when the air handler has no heat or if its heat is disabled during unoccupied periods, and the VAV boxes are equipped with reheat but have no fan.

The central fan is used to:• Provide air flow allowing VAV

boxes to use their local heat• Circulate air between interior and

exterior zones to facilitate the warm-up process

The VAV box controls local heat to its occupied setpoints when its mode is Warm-up.

Schedule editorCreate an HVAC Schedule with an optimal window defined with an 8:00 AM start. Add the Area as a member of this schedule.VAS editor (Setup tab)Enable the local heat.

The Area's space tempera-ture is 65°F (18.3°C) and you want to warm it up so that it gets to 70°F (21.1°C) just as the building is occupied at 8:00 AM. So warm-up begins at 7:10 AM. The air handler has no heat and the VAV boxes are configured with hot water reheat.

Table 12. Optimal Start heating scenarios (continued)


Figure 80. Humidity Pull Down Settings




Sequence

Area implements Humidity Pulldown as follows:

1. Area determines the actual time to control the operating mode of VAV boxes to Humidity Pull Down based on the Area inside humidity sensor, the occupied humidity setpoint, and the associated humidity pull down start rate.


• The Area operating mode transitions to Humidity Pull Down.

• The operating mode of the Area cooling only and heating/cooling members transitions to Humidity Pull Down.

Example:

Initial space humidity = 55% Humidity pull down rate = 8 min/% RH (learned by Area) Occupied start time = 8:00 AM Optimal window = 6:00 to 8:00 AM Occupied humidity setpoint = 50%

Area calculates the humidity pull down time as follows:

(55% - 50%) x 8 min/% RH = 40 minutes

Warm-up with Normal Start (No Optimal Start)

Warm-up with a normal start occurs when there is no optimal window defined in the HVAC schedule, and the schedule controls the Area occupancy from Unoccupied to Occupied. The air handler compares the active space temperature it is receiving from VAS against its occupied heating setpoints to determine whether to produce hot air or cold air.

Figure 81. Humidity Pull Down

is locked out

SpaceHumidity

InitialSpaceHumidity

55%

Humidity Pull DownEnds

Humidity Pull DownBegins

50%

8:00 AM

OccupiedUnoccupied

OccupiedHumiditysetpoint

Calculated Humidity Pull Down Time

7:20 AM




Daytime Warm-up

Important: Daytime Warm-up is a function of the AHU controller. Specific setpoints and deadbands may vary between AHU controllers.

Daytime Warm-up occurs during occupied periods. When the air handler’s space temperature is colder than its “Daytime Warm-up Setpoint”, the air handler supplies hot air to the system. When the space becomes too cold again, Daytime Warm-up runs again.

Follow the best practices defined in “Controller Setup,” p. 33 and sending the VAS Average Space Temperature calculated in the VAS to the VAV air handler space temperature point (Figure 82). Use Tracer TU to create this TGP2 program and download it to the Tracer SC controlling the VAV air handler.

Optimal Stop

Optimal stop is an energy saving feature managed by the HVAC Schedule and Area applications. During optimal stop the zone temperature is allowed to rise above the Occupied cooling setpoint or fall below the Occupied heating setpoint. The VAV boxes control to their Occupied Standby setpoints. The air handler behaves as it does when it’s in the Occupied mode.

Cooling (Area is in the Cooling Mode)

1. Area determines the actual time to control the operating mode of VAV boxes to Optimal Stop based on the space temperature sensor, the occupied cooling setpoint plus 2°F (1.1°C)(not editable), and the associated cooling optimal stop rate.

2. When the stop time falls within the window of opportunity provided by the Schedule, the operating mode of the Area and its VAV members transition to Optimal Stop.

Example:

Initial space temperature = 73.5°F (23°C) Cooling Optimal Stop rate = 14 min/°F (25.2 min/°C)(learned by Area) Unoccupied start time = 5:00 PM Optimal Stop window = 3:30 to 5:00 PM Occupied cooling setpoint = 74°F (23.3°C)


((74°F + 2°F) - 73.5°F) x 14 min/°F = 35 minutes

or

((23.3°C + 1.1°C) - 23°C) x 25.2 min/°C = 35 minutes

Figure 82. TGP2 space temperature control program




Heating (Area is in the Heating Mode)

Heating is similar to cooling during optimal stop with the exception that Area determines the actual time to control the operating mode of VAV boxes to Optimal Stop based on the space temperature sensor, the occupied heating setpoint minus 2°F (1.1°C), and the associated heating optimal stop rate.

Example:

Initial space temperature = 70.6°F (21.4°C) Cooling Optimal Stop rate = 15 min/°F (27 min/°C)(learned by Area) Unoccupied start time = 5:00 PM Optimal Stop window = 3:30 to 5:00 PM Occupied heating setpoint = 71°F (21.6°C)


(70.6°F – (71°F – 2°F)) x 15 min/°F = 24 minutes

or

(21.4°C – (21.6°C – 1.1°C)) x 27 min/°C = 24 minutes

Figure 83. Optimal stop cooling (shown in °F)

is locked out

SpaceTemperature


76° F

Optimal StopEnds

73.5° F

74° F

5:00 PM

Unoccupied


Calculated Optimal Stop Time

4:25 PM




Setup

Create an HVAC Schedule with an optimal window defined and an Area added as a member. The stop event must occur within the defined optimal window.

Night Purge (Night Economizing)

Night purge, which is also known as night economizing, is an efficient way to pre-cool a building in the late-night/early-morning hours without using chilled water or direct expansion (DX) cooling. Its function is to cool the space by exchanging warm inside air with cool, dry outdoor air.

Note: Dry climates are more likely to provide suitable outdoor air conditions for Night Purge than humid climates.

The intent of Night Purge is to minimize or possibly eliminate the need for mechanical cooling when the space initially becomes Occupied. An additional benefit is the potential to improve indoor air quality.

Night purge only occurs if all of the following are true:

• the Area must be unoccupied.

• night purge must be enabled within the Area application.

• night purge must be scheduled within the Area application.

• the current time is within the scheduled time to night purge.

• Area's space temperature sensor must be warmer than its occupied cooling setpoint by 1°F (0.56°C).

• Area is in cooling mode.

• Night Purge's Economizing decision must be Enabled (refer to “Setup,” p. 130 for more information).

• Area's outdoor air temperature must be colder than its space temperature sensor by the amount specified in the Outdoor/Space Temperature Differential field (refer to “Setup,” p. 130 for more information).

Figure 84. Optimal stop heating (shown in °F)

is locked out

SpaceTemperature

InitialSpace Temperature

71° F

69° F

Optimal StopEnds

70.6° F

5:00 PM

Unoccupied

OccupiedHeatingsetpoint

Calculated Optimal Stop Time

4:36 PM




For normal AHU systems, outside dampers are open and return air dampers are closed. All exhaust fans operate at full speed.

All night purge VAV members of the Area control to their occupied cooling setpoint.

Night purge ends when any of the following is true:

• The current time is outside the scheduled time to night purge.

• The night purge input is disabled.

• The outdoor temperature is above the space temperature.

• The Area transitions to a heating mode.

• The space temperature falls below its occupied cooling setpoint minus the binary control differential (1°F (.56°C)).

Setup

Setup for Night Purge occurs in the Area function page for the selected Area.

1. Enable Night Purge.

2. Click the referencer icon for Economizing decision.

3. The Referencer page appears, select the pre-defined referencer for the Area Economizing decision.

Note: If desired, a binary point may be referenced to the Economizing decision input. This input allows additional criteria, such as unit economizing decisions to be used.

4. Set the inside/outside temperature differential to 15°F (8.3°C)(default).

Note: The outdoor air temperature must be below the space temperature, minus the value in the Outdoor/Space Temperature Differential field, before Night Purge occurs.

5. Schedule the Night Purge windows (seven possible—one for each day).

6. Select the Area VAV box members that will respond to Night Purge events (Figure 85, p. 131).

The Night Purge window (on the Area Function page) should be scheduled to occur during the coolest time of the early morning, typically just before sunrise. For example, if sunrise is at 6 AM or later, schedule Night Purge from 4 to 6 AM.

BestPractice

The Area Economizing decision should be enabled. The referencer for the Night Purge Economizing decision should be set to look at the Area Economizing decision.Best

Practice




Example: A building has been unoccupied over the weekend and the internal temperature has been maintained at 82°F (27.8°C) by the Area Unoccupied Heating/Cooling function. A Night Purge event will occur at 4 AM Monday morning under the following conditions.

• Night Purge is enabled.

• The Night Purge Economizing decision is enabled.

• The outdoor/space temperature differential is set to 15° (8.3°C)

• A Night Purge window is configured to occur between 4 AM and 6 AM.

• The Area occupied cooling setpoint is 75°F (23.9°C).

Night Purge will exchange the 82°F (27.8°C) air from inside the building with the cooler outdoor air.

Figure 85. Area member function page

Figure 86. Night Purge example (shown in °F)

is locked out

SpaceTemperature


82° F

NightPurgeEnds

NightPurgeBegins

75° F

74° F

6:00 AM


4:00 AM




Unoccupied Humidification

Unoccupied Humidification is the process of the HVAC Schedule and Area functions working together to increase the humidity in a building during unoccupied times to maintain a minimum humidity level within the space.

Note: The air handler may keep the outdoor air damper closed during Unoccupied Humidification because it occurs during Unoccupied periods. The Area occupancy request remains Unoccupied by the HVAC Schedule; the Area occupancy status transitions to Occupied.

To Set Up Unoccupied Humidification:

Follow these steps to set up Unoccupied Humidification:


2. Enable Unoccupied Humidify (Figure 87).

3. Enter an Enable Humidification Setpoint (default is 20%).

4. Enter an Disable Humidification Setpoint (default is 25%).

5. Add Members to the Area with the humidification check box selected.

6. Create an HVAC Schedule and add the Area to the schedule as a member.

Important: Humidification members are air handlers with humidifiers, or binary outputs controlling humidifiers that are also a member of the Area. Insure that these members are configured as humidification members when adding them to the Area.

Sequence

Area implements Unoccupied Humidification as follows:

1. When the Area is Unoccupied and Unoccupied Humidification is Enabled, Area compares the space humidity with the Enable Humidification Setpoint. When the space humidity falls below the Enable Humidification Setpoint, the Area operating mode transitions to Unoccupied Humidification. When this transition occurs:

• All humidification members of the Area transition to Unoccupied Humidify.

• All members of the Area not designated as humidification members remain Unoccupied or Off.

2. When the space humidity rises above the Disable Humidification Setpoint, the Area operating mode transitions to Unoccupied. When this transition occurs:

• All humidification members of the Area transition to Unoccupied or Off.

• All members of the Area not designated as humidification members remain Unoccupied or Off.

Figure 87. Unoccupied Humidify Settings




Example:

Initial space humidity = 26% Enable Humidification Setpoint = 20% Disable Humidification Setpoint = 25%

Note: Area occupancy request, remains Unoccupied until an HVAC Schedule controls it to Occupied; the occupancy status will transition to Occupied during this mode.

Unoccupied Dehumidification

Unoccupied Dehumidification is the process of the HVAC Schedule and Area functions working together to decrease the humidity in a building during unoccupied times to maintain a maximum humidity level within the space.

Note: The air handler may keep the outdoor air damper closed during Unoccupied Dehumidification because it occurs during Unoccupied periods. The Area occupancy request remains Unoccupied by the HVAC Schedule; the Area occupancy status transitions to Occupied.

To Set Up Unoccupied Dehumidification:

Follow these steps to set up Unoccupied Dehumidification:


2. Enable Unoccupied Dehumidify (Figure 89).

3. Enter an Enable Dehumidification Setpoint (default is 60%).

4. Enter an Disable Dehumidification Setpoint (default is 55%).

5. Add Members to the Area with the dehumidification check box selected.

6. Create an HVAC Schedule and add the Area to the schedule as a member.

Figure 88. Unoccupied humidification

is locked out

SpaceHumidification

25%

HumidificationEnds

HumidificationStarts

20%

EnableHumidificationsetpoint




Sequence

Area implements Unoccupied Dehumidification as follows:

1. When the Area is Unoccupied and Unoccupied Dehumidification is Enabled, Area compares the space humidity with the Enable Dehumidification Setpoint. When the space humidity rises above the Enable Humidification Setpoint, the Area operating mode transitions to Unoccupied Dehumidification. When this transition occurs:

• All dehumidification members of the Area transition to Unoccupied Dehumidify.

• All members of the Area not designated as dehumidification members remain Unoccupied or Off.

2. When the space humidity falls below the Disable Dehumidification Setpoint, the Area operating mode transitions to Unoccupied. When this transition occurs:

• All dehumidification members of the Area transition to Unoccupied or Off.

• All members of the Area not designated as dehumidification members remain Unoccupied or Off.

Example:

Initial space humidity = 54% Enable Dehumidification Setpoint = 60% Disable Dehumidification Setpoint = 55%

Note: Area occupancy request remains Unoccupied until an HVAC Schedule controls it to Occupied; the occupancy status will transition to Occupied during this mode.

Figure 89. Unoccupied Dehumidify Settings

Figure 90. Unoccupied Dehumidification

is locked out

SpaceHumidity

60%

DehumidificationEnds

DehumidificationStarts

55%

EnableDehumidificationsetpoint




Timed Override

During unoccupied periods, a Timed Override request (typically initiated by pressing the On button at a zone sensor attached to a VAV box) controls the Area occupancy request to Standby at a higher priority than the Schedule for a specified duration.

Timed override ends when the time defined in the Duration field expires for the temporary override, or the Cancel button on a zone sensor in the Area is pressed. When Timed Override ends, the schedule regains control of the Area occupancy request.

Setup

Figure 91 details specific settings used to make Timed Override work properly.

Figure 91. Timed override setup. Area configuration page, operations frame

Timed override must be enabled.

Set the duration for a Timed Override (the default is 120 minutes)

Optional input is a multi-state point with the following enumerations:

1 = Normal

2 = Initiate Timed override

3 = Cancel

Figure 92. Timed override setup. Area Member configuration page

The zone sensors used to initiate the timed override must be connected to Area members enabled for Override (check box selected).




General Settings

These settings are considered best practices for each of these Standard Operating modes.

VAV Configuration

• Configure the VAV boxes prior to installing into Tracer SC.

• The Heat/Cool Request field is set to Auto.

VAV Box (Done in Rover for LonTalk Devices)

• Configured for space temperature control.

• Auto calibrate is enabled.

• Star and double star (*/**) is not enabled (check box is not selected in the Rover editor).

• Auto changeover setpoint = 80°F (26.7°C) (Rover setting, Configuration > Unit tab).

• Occupied bypass time = 0 min.

Variable Volume Air Handler

• The air handler is a variable air volume unit.

• Configure the air handlers prior to installing into Tracer SC.

• Heat/Cool Request: = Auto

• Space Temperature Sensor BAS = VAS Average Space Temperature (done using TGP2, refer to Figure 82, p. 127).

• The air handler has no local space/morning warm-up temperature sensor.

Area Configuration

Configure page - Setup

• Area Heat/Cool Request: = Auto (Configuration page)

• Reference the Space Temperature Sensor (Configuration page, Setup) to the pre-defined referencer for the Area Average Space Temperature.

• Reference the Outdoor Air Temperature Sensor (Configuration page, Setup) to the pre-defined referencer for the Facility Outdoor Air Temperature.

• If Economizing with Enthalpy or Dew Point, reference the Space Humidity sensor and the Outdoor Air Humidity sensor (not shown as referenced in Figure 93).




Configure page - Operations

• Select Enabled for Unoccupied Heating/Cooling in the Area Configuration Operations section.

• Outdoor Air Temperature Compensation is Enabled (refer to Figure 94).

Members configuration

• Each VAV box is a Heat/Cool member of the Area. (select Add or Edit Members on the Members page).

Figure 93. Area Configure page, Setup section

Figure 94. Area Configuration, Operations section

Set these references.

Verify that the Heat Cool Request is set to Auto

These must be enabled.




• The Calculations, Override, and Night Purge check boxes are selected for each VAV member (Members Configuration page). If performing humidification or dehumidification, those check boxes must also be selected.

VAS Configuration

• All of the VAV boxes, which are part of the VAV system, should be defined as members of the VAS.

• Select the Allow VAVs to use auxiliary heat at night check box.

• Select the Send source temperature to VAV boxes check box.

• Select the Send drive max to VAV boxes check box.

• Air Handler Startup Delay = 2 min.

• VAV Box Shutdown Delay = 5 min.

• The VAV AHU Startup Setpoint is set to 72.0°F (22.2°C).

• Calibration Trigger is set to Normal.

Figure 95. Setting the Heat/Cool Request

Figure 96. Area Member Types (with no humidity control)




• Select the appropriate optimization strategies for the installation.

• If using an MP580/581, it MUST be configured with a DAC profile in order to be an AHU member of the VAS.

Scheduling Configuration

• Each Area must be a member of either an HVAC Schedule or a Multi-State Schedule

Note: Optimal functions are only available when the Area is a member of an HVAC Schedule.

Figure 97. VAS Configuration page



Commissioning

This section discusses the commissioning process of a variable air system. The intended audience is the field startup technician with the last section devoted to air balancing. It is important to note that the LonTalk VAV system commissioning process differs dramatically from previous air systems due to the unique ability of the VV550/551 controllers to perform auto-commissioning. Consequently, new best practices are now being recommended.

Best Practice for Commissioning:

• Commission the Air handler. Basic AHU checkout procedures for a VAV AHU including the duct static pressure sensor, water valves, external heat, zone sensor and Traq dampers

• Check out the communications link. Basic procedures in checking out communication links as well as a short guide in troubleshooting common problems.

• Configure the VAV controllers. (Refer to “VAV Box Configuration,” p. 40)

• Install VAV boxes on the SC and program Area and VAS in Tracer SC. (Refer to “Tracer SC Application Setup for Variable Air Systems,” p. 72).

• Auto-commission Trane VAV controllers. A “how to” on checking out VAV control dampers, water valves, and sensors.

• Perform air and water balance. Provides a overview of the Rover Air and Water Balance tool which is required for balancing the VAV boxes.

Air Handler Commissioning

To commission the air handler for the purposes of setting up the Tracer SC VAS, consider duct static pressure control (refer to “Static Pressure Sensor Control,” p. 34) and discharge air temperature control. These are the only items needed for the Tracer SC VAS and the Rover service tool to auto-commission the VAV box controllers.

Conduct a more comprehensive startup and checkout of the AHU. This includes verifying proper operation of all temperature and humidity sensors as well as all damper and any airflow monitors. This work is beyond the scope of this document and is not covered here.

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Commissioning

Commissioning the Communications Link

Next to equipment checkout, troubleshooting a communication link can be the most time consuming task on a job. This section discusses the procedures to use to effectively checkout a communications link. Refer to Unit Controller Wiring for Tracer SC, BAS-SVN03A-EN for more information.

Preliminary Checkout for LonTalk Links

Determine the resistance of the link. This test provides an overall idea of the integrity of the link. Under typical conditions, a communications link wired with level 4 wire and terminated with 105 Ω termination resistors should read approximately 52 Ω plus approximately 8 Ω per 1,000 feet of wire. Figure 98 shows what the expected resistance should be for a given length of wire.

If the measured resistance does not fall within the expected values, most of the time it is possible to determine the nature of the problem from the resistance readings. Table 13 shows some typical resistance readings for communications links when various problems occur along with the effects and what to look for when these problems exist. The most common communication link issues are shorts, open links, or the wrong number of resistors installed on the link. Most of these problems can be found quickly using a multi-meter to check for link resistance. This can be done with or without the devices powered up.

Figure 98. Wire resistance graph

035

40

45

50

55

60

65

70

75

80

85

90

500 1000 1500 2000 2500 3000 3500 4000 4500

Wire Length (ft)

High

Low

Mea

sure

d R

esis

tanc

e (O

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Commissioning

Finding a Short

Shorts are the most common issue related to communication links. If a short occurs anywhere in the communications link, a resistance reading between 0 Ω and 10 Ω is typically seen. The easiest way to determine where the short occurs is to use the divide and conquer technique. This technique is the fastest way to locate most communications issues and does not require a computer or a service tool. On a link of 60 devices the problem can typically be found in no more than six steps.

The first step after a problem is detected is to select a device that is approximately in the middle of the link. At the middle device remove one side of the communication link, which effectively splits the link into two separate links (refer to Figure 99). The resistance is then read on each of the two links from the split back to the termination resistors located at each end of the link. One of the two links will read a short and is the link that contains the problem. The other link reading should be reading the termination resistor plus the resistance of the wire. Reconnect the communication link and select a device that represents half the length from the previously tested device and the end of the link which showed the short. Using the same procedure, measure the resistance of each link. This procedure is repeated until the wiring problem is located.

Table 13. Troubleshooting at specific resistance readings

Measured Range Effects Look For:

OL (overload), Infinite,

• Circuit is completely open. • Communication failures are seen in the event

log• LonTalk units not found during discovery.

1.Check ohmmeter leads.2.Check termination resistors.3.Check for open wire connections.

95-Ω to 130-Ω

• One of the termination resistors is not connected.

• Communication failures may or may not be seen in the event log.

• LonTalk units may be dropping out intermittently.

• LonTalk units may or may not be found during discovery.

• LonTalk repeater will not work correctly.

1.Missing or damaged termination resistor at one end of the link.

2.An improperly connected termination resistor.

50Ω to 90Ω (Normal)• Correct resistance measurement. • Normal operation

The termination wiring is done correctly. Use other troubleshooting techniques if there is still a problem.

21Ω to 40Ω

• Too many termination resistors. The site may have been reconfigured. This typically shows no symptoms at the BAS level.

• LonTalk repeater may not work correctly.

1.Verify that the site topology is daisy chain. 2.Check for extra termination resistors.

0Ω to 10Ω

• There is a short between the two conductors.• Communication failures are seen in the event

log• LonTalk units not found during discovery.

Check for short between conductors.

∞



Commissioning

Finding an Open Circuit

The same procedure for finding a short in the link can be used to locate an open circuit (communication link is not terminated or has an open termination).

Reading too high a resistance on the link indicates that one of the termination resistors is missing or the link has a break somewhere between the two termination resistors. Verify that both resistors are installed and read the resistance of the link at each device where the resistor is installed. If the resistance at both ends of the link are approximately equal to the resistor plus some resistance of the communication wire then it is safe to assume that the communication link has a break somewhere between the two end devices.

Rover is helpful in determining where the break is located. The installation contractor should provide as-built documents that show how the communication link was actually installed. Use Rover to discover the devices on the link and the as-built documents to determine how many devices should be on the link. It should be possible to find the approximate location of the break in the link.

Using Figure 99 as an example, Rover should find three devices when connected to one end of the communication link or two devices when connected to the other end of the communication link. The as-built document should indicate that there are five devices on the link.

Figure 99. Broken link

VAV 03-01

VAV 03-02

VAV 03-03

VAV 03-04

VAV 03-05

Ω

Ω

Break the link here and test the resistance on each end to find the open circuit

Open circuit



Commissioning

Preliminary Checkout for BACnet Communication Links

Before you install a BACnet link, devise an address scheme for all the devices on the BACnet link and then adhere to that scheme. BACnet links operate on MS/TP protocol which dictates that every device on the link has a unique address. If duplicate addresses occur on the same link, the token being passed is dropped and communication on the link stops. Once this occurs, it is very difficult to determine where the problem is on the link (refer to “Troubleshooting Scenario,” p. 145)

Other things to consider during installation of the devices that will make commissioning and troubleshooting the link much easier:

• Make sure the devices are wired properly (proper terminations and polarity).

• Label the communication wiring “IN” from the Tracer SC and “OUT” to the next device at each device. This makes troubleshooting the link much easier. It helps you to know you have included or excluded the device when splitting the link without trial and error.

The most useful tool for troubleshooting the BACnet link is the Tracer SC itself. All of the issues below can be discovered by using divide-and-conquer methods. If any BACnet device on the link is powered up, a digital volt meter will not provide useful information when troubleshooting a BACnet communication link. The most frequently encountered problems on an MS/TP BACnet link are:

• An open circuit

• A short circuit

• A duplicate MAC address (duplicate rotary address on the UC)

• UCs that are not addressed (0,0,0 on the UC’s rotary switches)

Before troubleshooting the link, you should have a valid set of prints for the project that show you how the devices are wired on the link along with their addresses.

The following steps define the general troubleshooting tasks for BACnet links.

1. From the Tracer SC, verify the following:

a. Verify the rotary address setting on the SC (make sure it’s rotary switches match the submittal documents). If you change the rotary switches, verify the Tracer SC BACnet configuration using the Tracer SC (Installation > Identification and Communication > BACnet Configuration)

b. Verify the shield wires are properly terminated per the wiring diagrams.

c. Verify the communication wiring terminal is fully seated on the controller.

d. Verify the polarity of the comm link.

e. Verify that both the in and out are properly terminated on the terminal by performing a tug test on each wire.

2. Verify that a Tracer BACnet Terminator is properly installed on each end of the comm link.

3. Go to the middle of the link and check the following items. If you find any of these items to be improperly installed, correct the problem and rediscover using the Tracer SC (Step 4):

a. Verify the rotary address setting on the UC (make sure it’s rotary switches match the submittal documents). If you find switches set incorrectly, you must change the rotary address and then cycle power on the UC.

Devise an address scheme for all the devices on the BACnet link and then make sure both the installer and BAS technician adhere to that scheme. Best

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Commissioning

b. Verify the shield wires are properly terminated per the wiring diagrams (and per wiring guidelines).

c. Verify the communication wiring terminal is fully seated on the controller.

d. Verify the polarity of the comm link.

e. Verify that both the in and out wires are properly terminated on the terminal by performing a tug test on each wire.

4. Using Tracer SC, discover the link.

5. If all devices are discovered, the problem exists on the outward side (away from the Tracer SC) of the broken link.

a. Reconnect the link and move half-way farther out on the link and break the link there.

b. Discover the link with Tracer SC.

c. Repeat step 3 until the trouble is isolated.

6. If not all the devices are discovered, the issue with the BACnet link is on the inward side of the broken link.

a. Reconnect the link and move half-way back toward the Tracer SC and break the link there.

b. Discover the link with Tracer SC.

c. Repeat step 3 until the trouble is isolated.

Troubleshooting Scenario

The following example shows a typical troubleshooting scenario. The example uses a limited number of UC devices to help illustrate the procedure. Most installations have many more UCs installed. A link of 30 devices should take no more than five steps to isolate a problem using the divide-and-conquer method.

Important: To communicate properly, the baud rate for all devices must be the same when they reside on the MS/TP link. The factory default setting for the baud rate on the UC400 is 76,800. The factory default setting for the baud rate on the Tracer SC is Disabled. Therefore, you have to configure the baud rate on the Tracer SC to match the UC400.



Commissioning

The installation for this example (as shown in Figure 100) has a single Tracer SC with six BACnet devices connected on the communication link and is terminated on each end of the link with a Tracer BACnet Terminator.

The BACnet device in the fourth position (UC-004) has been installed on the project without it’s rotary switches being properly set (they were left at 0,0,0, which is the factory setting).

Important: The Tracer SC and the UC400 are shipped from the factory with their rotary switches set at (0,0,0). The Tracer SC always uses a MAC address of (0). The UC400 determines it’s MAC address from its rotary switches. Therefore, when UC400s are installed on a project, the rotary switches need to be reset to a specific and unique address (from 1-127). If the UC400 factory setting is not changed, the UC400 ends up with the same MAC address as the Tracer SC (which is 0). When this happens, the token is lost on the MasterSlave/TokenPassing (MS/TP) link.

Since there are two MAC addresses on the BACnet link that are the same, the Tracer SC will typically discover no devices on the link. The technician should follow this process to isolate and find the problem:

1. Per step 1 in the preliminary checkout procedure above, the technician should do the following at the Tracer SC.

a. Check the rotary address setting on the SC.

b. Check the shield wire terminations.

c. Check the seating of the communication wiring terminal on the controller.

d. Check the polarity of the comm link.

e. Perform a tug test on each wire.

Figure 100.BACnet Link Troubleshooting Scenario

UC-003UC-005 UC-000 UC-002 UC-001

Tracer SC-101 TracerBACnet

Terminator

LINK 1

+–

LINK 1

+–UC-006TracerBACnet

Terminator

TracerBACnet

Terminator

TracerBACnet

Terminator

UC 400 Tracer SC



Commissioning

2. Make sure there is a Tracer BACnet Terminator at each end of the link, and that the wiring is terminated properly.

3. Go to the middle of the link (UC-003) and check the following items. If any of these items are improperly installed, correct the problem and rediscover using the Tracer SC (step 4 below and refer to Figure 101):

a. Verify the rotary address setting on the UC400 (make sure it’s rotary switches match the submittal documents—in this case UC-003). If you find switches set incorrectly, you must change the rotary address and then cycle power on the UC.

b. Check that the shield wires are properly terminated per the wiring diagrams (and per wiring guidelines).




4. Using Tracer SC, discover the link. In this scenario, all devices should be discovered, this means the problem exists on the outward side (away from the Tracer SC) of UC-003.

5. Reconnect the link and move half-way farther out on the link from where it was broken in the first jump and break the link (at UC-005)(refer to Figure 102, p. 148).

6. Per step 1 in the preliminary checkout procedure above, the technician should do the following:

a. Verify the rotary address setting on the UC400 (make sure it’s rotary switches match the submittal documents—in this case UC-005). If you find switches set incorrectly, you must change the rotary address and then cycle power on the UC.

b. Check that the shield wires are properly terminated per the wiring diagrams (and per wiring guidelines).


Figure 101.Divide and Conquer Technique on the BACnet Link—First Jump

UC-003(address: 0,0,3)






Terminator

LINK 1

+–

LINK 1

+–UC-006(address: 0,0,6)

TracerBACnet

Terminator

3

UC400



Commissioning



7. Discover the link with Tracer SC. In this scenario, the Tracer SC would fail to discover the devices on the connected link; indicating that the problem lies between UC-005 and UC-003. Therefore, the technician needs to relocate to UC-004.

8. Per step 1 in the preliminary checkout procedure above, the technician should do the following:

a. Verify the rotary address setting on the UC400 (make sure it’s rotary switches match the submittal documents—in this case UC-004). In this scenario, the switches are still at their factory default setting of (0,0,0) so they need to be changed to (0,0,4).

b. Cycle power on the UC (refer to Figure 103, p. 149).

Figure 102.Divide and Conquer Technique on the BACnet Link—Second Jump







Terminator

LINK 1

+–

LINK 1

+–UC-006(address: 0,0,6)

TracerBACnet

Terminator

5

UC400



Commissioning

Auto-commission the Tracer VV550/551 and UC400 Controllers

The Tracer VV550/551 and UC400 VAV controllers include a special operating sequence designed to validate the proper operation of all outputs and the ability to measure all inputs. The purpose of this sequence is to minimize the labor required to commission the unit in the field. Full use of this function requires the presence of an auxiliary temperature sensor configured as a discharge air sensor and placed in the discharge air stream. Without an auxiliary temperature sensor in the discharge air stream, fan and reheat operation cannot be validated and will not be tested. The air handler must also be operational and making cold air, and, if using hot water heating, the boiler must be on and operating.

This sequence is initiated via a command from Tracer SC’s VAS or VAV Configuration pages or from a Trane service tool. When the auto-commissioning command is initiated from the VAV Configuration page or a service tool, you can only initiate auto-commission on one VAV at a time. Tracer SC’s VAS editor can auto-commission all the VAVs in the VAS at once (but staggered). The results are stored locally in the controller. Access the results using either Tracer SC, the Rover service tool, or Tracer TU.

Figure 103.Divide and Conquer Technique on the BACnet Link—Third Jump







Terminator

LINK 1

+–

LINK 1

+–UC-006(address: 0,0,6)

TracerBACnet

Terminator

8

UC400

Change from 0,0,0 to 0,0,4

For each VAV box, install an auxiliary temperature sensor, configured as a discharge air sensor, in the discharge air stream to allow the most complete auto-commissioning of the VAV box.Best

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Commissioning

Things to Consider Before Auto-commissioning

Before initiating auto-commissioning, be sure to consider the following:

• Is the equipment, especially the AHU, under Tracer control?

• Is the AHU making cold air?

• Is the chilled water system on?

• Is the boiler system on?

• Are fire dampers in the duct system all open?

• Is the static pressure setpoint fixed at design defaults (optimization is disabled in VAS)?

Important: A discharge air temperature sensor is required for valid auto-commissioning temperature data.

Auto-commissioning Individual VAV Boxes with the Service Tools

Individual VAV boxes can be commissioned using the service tool.

Rover Service Tool-VV550/551 Controllers

Figure 104, p. 151 shows Rover’s auto-commissioning report for a VAV box.

To start the auto-commissioning sequence:

1. Select the Commissioning tab.

2. Click Start in the Auto-commissioning group.

Have the air handler making cold air under static pressure control and have hot water available at the VAV box if a hot water valve is present.Best

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Commissioning

Tracer TU Service Tool-UC400 VAV Controllers

Figure 105, p. 152 shows Tracer TU’s auto-commissioning report for a VAV box.

To start the auto-commissioning sequence:

1. Select the VAV box from the left-hand navigation.

2. Select the Equipment Utility tab along the right edge of the screen (the wrench).

3. Click 3. Commissioning from the tabs along the top.

4. Expand the Actions section.

5. Click Start.

6. The Commissioning dialog box appears. All previous commissioning reports are listed. Click Start to begin auto-commissioning the VAV box selected in step 1.

Figure 104.Example of Auto-commissioning in Rover



Commissioning

Auto-commissioning All VAV Boxes with Tracer SC

Trane recommends performing system checkout by exception. A quick way to see how all the VAV boxes and the air handler in the system are performing is to run the auto-commissioning sequence in the VAS editor. After the auto-commissioning test is run, a report can be generated, the results can be analyzed, and problems can be addressed.

The auto-commissioning report is also an important documentation tool. It demonstrates, in writing, that all of the components have been tested and are functioning.

Generate an Auto-commissioning Report

1. In Tracer SC select Reports from the left-hand navigation. The Standard Report Definition page appears.

2. Select VAV Commissioning Report in the Report Definition Category list box.

3. Select the check box for VAS VAV Auto Commissioning.

4. Click actions... > run.

Figure 105.Example of auto commissioning in Tracer TU

If duct static pressure optimization is used, the system may not respond in time to satisfy the short term high demand of the VAV during the auto-commissioning phase. Disable the duct static pressure optimization feature in the VAS editor during the auto-commissioning process.

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Commissioning

5. Once started the auto-commissioning function goes to each VAV box and runs it through some operation performance tests (refer to Table Note:, p. 154) and records the results (refer to Figure 108, p. 155). How long it takes for each VAV box depends on the configuration of the box. VAV boxes configured with fans and heat take longer than those that do not. Auto-commissioning follows this sequence:

a. The SC divides its VAV members into six groups (common space members are distributed as evenly as possible among these groups).

b. The SC then staggers the command to auto-commission each VAV group by 15 minutes. The first group begins immediately; the second group 15 minutes later; the third group 15 minutes after that, and so on. The last group begins auto-commissioning 75 minutes after initiating the auto-commissioning command. When a particular VAV box gets the command to auto-commission, it calibrates and then runs through a sequence of operation performance tasks as described in Table 14

Figure 106.Selecting the Auto-commissioning Report

Figure 107.Selecting which VAS to Auto-commission



Commissioning

Note: The data generated during the auto-commissioning sequence is stored on the controller. Tracer SC harvests this data to populate the auto-commissioning report. New data overwrites existing data on the controller each time auto-commissioning occurs.

The auto-commissioning report contains the following information about the VAS air system:

• The VAV box name.

• Whether there are alarms present.

• The zone temperature and its setpoint.

• Active airflow (in cfm).

• When the VAV box was tested as part of the report.

• The air valve position when the VAV box reaches 40% of Maximum cooling setpoint.

• The air valve position when the VAV box reaches 100% of Maximum cooling setpoint.

• The discharge air temperature of the VAV box when the fan is off.

• The discharge air temperature of the VAV box when the fan is on.

• The discharge air temperature of the VAV box when the hot water heat is on (if applicable).

• If the box is equipped with electric heat, the report shows temperatures measured when one stage of heat is turned on, when two are turned on, and when three are turned on.

Table 14. VAV Auto-commissioning sequence

Item Test action Reported Data

Primary air valve and airflow test

Turn fan and reheat off. Stroke the air valve and modulating hot water valve (if present) closed and calibrate flow sensor. Then drive air valve open, record position of air valve at 40 and 100% of cooling max airflow setpoint.

Position values for 40% flow and 100% flow

Fan flow

Open primary air valve to cooling max airflow setpoint and record the discharge air temperature. Close primary air damper. Turn fan on. Monitor the discharge air temperature for 3 minutes or until it changes by 10 degrees F.

Discharge air temperature at beginning and end of step.

Local Reheat water

Open primary air valve to active minimum flow setpoint (close primary air valve and turn on fan for fan powered units). Record the discharge air temperature. Open water valve(s) 100%. Record the discharge air temperature for 10 minutes or until it changes by 10 degrees F.

Discharge air temperature at beginning and end of step.

Local Reheat electric

Open primary air valve to active minimum flow setpoint (close primary air valve and turn on fan for fan powered units). Record the discharge air temperature. Progressively turn on each stage 30 seconds after the previous stage until all stages are energized. Record the discharge air temperature 30 seconds after each stage is energized.

Discharge air temperature for each stage of electric heat energized



Commissioning

Interpreting the Auto-commissioning Report

Verifying the Air Valve Operation:

Examine the reported flow values when the air valve position at is at 40% and 100% of maximum flow in the report. These values help the technician determine if the air valve is functioning properly. Note that if there is insufficient static pressure being delivered by the AHU, the reported air valve position could read 100% at maximum flow.

If the air valve reports N/A (or “---”) at both the 40 and 100 percent flows some possible causes are (assuming the VAV box is in pressure-dependant mode):

• Failed DP sensor

• High or low pressure tube is clogged or not connected

• Flow ring is defective (high and low sides are not separated)

• There is no airflow sensor installed

• Flow sensor calibration has failed

• There is no airflow/AHU is off

Verifying Fan Operation

The auto-commissioning process is an aid in verifying proper fan operation. To accomplish this, a fan and discharge temperature sensor must be configured and present in the VAV box. The auto-commissioning process records the discharge temperature with the VAV air valve driven to

Figure 108.Auto-commissioning sequence results



Commissioning

maximum flow and with the fan off. It then turns the fan on and drives the air valve closed. If the fan runs, it draws warm plenum air in through the box and out past the discharge air temperature sensor. A rise in the discharge air temperature indicates that the fan is operating. No change in temperature indicates that the fan did not start.

Note: The plenum air should be warmer than the primary air source.

Verifying Reheat Operation

If a fan is present, the auto-commissioning sequence drives the air valve to closed. If no fan is present, the air valve opens to the configured minimum local heating airflow. It then turns off the reheat and records the discharge air temperature.

Auto-commissioning then turns on the reheat (the hot water valve is 100% open) and records a second discharge air temperature.

Compare the two discharge air temperature readings. If the “off” temperature is below the “on” temperature by the appropriate amount, proper operation of the reheat is inferred.

Note: If the VAV box has hot water reheat, hot water must be available at the VAV box.

Perform Air and Water Balance

The air and water balancing tool is a part of the Rover suite of software tools and Tracer TU. Testing, adjusting, and balancing professionals can use the tool to:

• Calibrate and balance VAV boxes

• View the flow readings from VAV boxes

• Override individual or groups of VAV boxes

• Override fan control and water valves on equipment

• Create a balancing report

Use the Rover air and water balancing tool to balance the air and water flow in the system (assuming water is being used). Refer to Trane document EMTX-SVU01“Operations: Air and Water Balancing Tool, Rover Version 7” for detailed information on using the Rover air balancing tool. Refer to the online help for Tracer TU for information on Air and Water Balance processes.



Optimization

The Tracer SC VAS has two standard features designed to minimize overall energy consumption of the VAV air system:• Duct static pressure optimization• Ventilation optimization


Duct static pressure optimization is a tool that resets the static pressure setpoint based on “real time” system demand allowing the system to operate at the lowest possible static pressure. The benefits are: • Reduced operating costs because the central fan requires less power during part load

conditions.• Reduced airflow noise during normal operation because the air dampers in the VAV boxes are

more fully open.

Static Pressure Sensor Location

The duct pressure sensor may be located anywhere along the length of the ductwork.

Setup Instructions for a Variable Volume Air Handler

When duct static pressure optimization is enabled in the Tracer SC VAS, the VAS writes the static pressure setpoint to the VAV AHU at the VAS priority (level 10).

Note: If ventilation optimization is not enabled, the static pressure setpoint should be released from VAS control on the Variable Volume Air Handler, Configuration page in Tracer SC.

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Install a duct static pressure sensor at the discharge of the fan. (refer to “Static Pressure Sensor Location,” p. 32 for more information)Best

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Optimization

Setup Instructions for an MP580/581 Air Handler

The MP580 must be programmed to use the “nviDuctStatPress” LonTalk network variable input. Refer to “Tracer Graphical Programming (in the MP580/581 using Rover),” p. 57 for further instructions on programming the MP580/581 controller.

Tracer SC VAS Duct Static Pressure Optimization Setup

Trane recommends waiting until after the system is balanced and commissioned before adjusting these values.

1. Select Systems > from the Tracer SC left-hand navigation.2. On the Systems list page, select the desired VAS from the variable air systems list.3. Click Function (either at the bottom or top of the page).

Figure 109. Setup for duct pressure optimization in the VAS editor

VAS uses this value if optimization is disabled (also referred to as the “design” pressure.

Maximum operating pressure allowed (often equal to the “design” pressure.

The increment is the amount the static pressure an be raised or lowered for each interval.

The interval is the point at which the static pressure setpoint is re-evaluated.

Values used to determine when to raise and lower the static pressure setpoint

Minimum operating pressure

If the system static pressure causes ANY air valve position in the VAV boxes to exceed the maximum air valve position setting, then the static pressure setpoint is adjusted up by the value in the increment field.

If the system static pressure causes ALL the valve positions in the VAV boxes to fall below the maximum air valve position setting, then the static pressure setpoint is adjusted down by the value in the increment field.

The Status box displays useful information about the active duct static pressure conditions in the VAS.



Optimization

4. Validate the maximum duct pressure setpoint with the air balancer. The default duct pressure setpoint is the duct pressure an AHU must maintain in order for all VAVs to supply their design airflow at peak capacity.

5. Verify that the Enable Duct Pressure Optimization check box is selected.Figure 110 shows the relation between the airflow and the position of the air valve in the VAV box. The graph shows that as the air valve begins to open and as it approaches 100% open, the airflow only increases in small increments. Most of the airflow variation occurs when the air valve is between 20% and 80% open. In this area of the graph, airflow increases roughly 2% for every 1% of modulation by the air valve. In order to implement the optimization routine most effectively, it is important to select limits that are still within the “dynamic range” of the damper.

Ventilation Optimization

Ventilation optimization is a tool that calculates the system outdoor air requirement based on “real time” conditions in the spaces (i.e., number of occupants, CO2 levels, etc.) minimizing the amount of unconditioned outdoor air that must be brought into the building. The benefit is reduced operating costs because less outdoor air must be conditioned (heated, cooled, humidified, or dehumidified) by the air handler while insuring that ventilation air reaches the zones where it is needed.

Ventilation optimization can be divided into two areas: zone level action which takes place at the VAV box, and system level action that takes place at the air handler.

Figure 110. Best practices for VAV air valve position limits

Airflow

0

Maximum

20% 80% 100%

VAV air valve position

Flow increases 2% for every 1% of damper movement

Dynamic range

Recommended settings:High limit = 75%Low limit = 65%



Optimization

Zone Level Action

At the zone level, there are four basic ventilation strategies supported by the Trane controller. The four strategies are: • Fixed ventilation• Occupancy-based ventilation• CO2-based, demand-controlled ventilation• Scheduled ventilation

Each strategy is set up a bit differently, and one or more strategies can be combined on a single system. The following four sections describe exactly what is required to support each strategy.

Strategy #1: Fixed Ventilation

Fixed ventilation, also known as design ventilation, is based on the design occupancy of the zone. The mechanical engineer will often calculate the ventilation requirements of a zone based on the peak occupancy plus an additional constant ventilation component based on the square footage of the zone (also referred to as the building component of ventilation).

Outdoor airflow requirement = (people outdoor air rate x design # of occupants) + (area outdoor air rate x zone square footage).

If a zone is designed for 24 people, then the ventilation rate will be set based on 24 people. The VAV box will use this ventilation setpoint whenever its operating mode is Occupied. Even at times of partial occupancy (i.e., only 15 people are in the zone instead of 24), the ventilation rate remains at design.

Example (IP): Fixed ventilation for a classroom designed to hold 24 students:• 1 Classroom = 400 ft.2

• people outdoor air rate = 10 cfm/person (based on ASHRAE 62.1)• design # of occupants = 24• people component = 10 x 24 = 240 cfm• area outdoor air rate = 0.12 cfm/sq. ft. (based on ASHRAE 62.1)• building component = 0.12 x 400 = 48 cfm• Occupied setpoint = 240 + 48 = 288 cfm• Occupied standby setpoint = 48 cfm (the building component)

Example (SI): Fixed ventilation for a classroom designed to hold 24 students:• 1 Classroom = 37.16 m2.• people outdoor air rate = 4.72 L/s per person (based on ASHRAE 62.1)• design # of occupants = 24• people component = 4.72 x 24 = 113.28 L/s• area outdoor air rate = 0.6 L/s per m2 (based on ASHRAE 62.1)• building component = 0.6 x 37.16 = 22.60 L/s• Occupied setpoint = 113.28 + 22.60 = 135.88 L/s• Occupied standby setpoint = 22.60 L/s (the building component)

Strategy #2: Occupancy-based Ventilation

This type of ventilation strategy requires a hardwired occupancy sensor on the controller. Configure the controller's binary input for Occupancy using the Rover or Tracer TU service tool.

During Occupied hours, when people are detected in the space, the controller uses the “Occupied Ventilation” setpoint. During Occupied hours, when people are not detected in the space (Occupied Standby), the controller uses the “Occupied Standby Ventilation” setpoint.



Optimization

When the occupancy mode of the VAV is Occupied Standby (the building is occupied but the zone is unoccupied), the zone only requires the building component of the ventilation rate. Under these conditions, the VAV uses the “Occupied Standby Ventilation” setpoint

Important: Occupied Standby Ventilation setpoint. The Occupied Standby Ventilation setpoint is the amount of outdoor air required to ventilate a zone during Occupied hours when no people are present (i.e., an empty conference room). Refer to ASHRAE 62.1 for detailed information.

Refer to the previous example for details on calculating the setpoints.

Setup for Fixed and Occupancy-based Ventilation Strategies for VV550/551

Controllers

To implement using the Rover service tool:

1. Select the VAV box to configure from the navigation tree. 2. Click Configuration.3. Select the Setup tab, the fields are in the Ventilation Setup group.

Note: Refer to the Flow Setpoints worksheet provided by the Trane project engineer (if available) for the value of both the occupied and occupied standby setpoints on each of the VAV boxes (see an example on p. 240).

Setup for Fixed and Occupancy-based Ventilation Strategies for UC400

Controllers

To implement using the Tracer TU service tool:

1. Select the VAV box to configure from the left-hand navigation. 2. Click Configuration.

Figure 111. Ventilation Setup setpoints (example shown in IP units)



Optimization

Strategy #3: CO2-based Demand Controlled Ventilation

Trane’s CO2-based ventilation strategy is an enhancement of the occupancy-based ventilation strategy. In this strategy, the active ventilation setpoint modulates between the occupied ventilation and occupied standby ventilation setpoints; it is reset based on CO2 levels in the space. (Figure 113, p. 162).

Figure 112. Tracer TU ventilation setup setpoints (example shown in SI units)

Figure 113. Minimum ventilation rate based on CO2 level

Space CO2Low Limit

Measured CO2 Level

Minimum Outdoor airsetpoint

Space CO2High Limit

Occupied StandbyVentilation Setpoint

OccupiedVentilation Setpoint

Out

door

Air

CO2 Level

Minimum ventilation for building and people

Minimum ventilationfor building only



Optimization

This ventilation strategy requires a communicated CO2 input to the Tracer controller from either a local binding (e.g., nviSpaceCO2), or from Tracer SC. When using Tracer SC, create a TGP2 program (using the Tracer TU service tool) that will read the Space CO2 Concentration from another source (such as an MP580 universal input) and then write it to the VAV Space CO2 Concentration BAS point (refer to “Tracer SC Setup for VAV boxes with communicated CO2 values,” p. 163).

Trane’s CO2-based, demand-controlled ventilation strategy is cost effective for the customer because it only places CO2 sensors in locations with widely varying occupancy patterns and population densities (i.e., conference rooms, break rooms, classrooms, cafeterias, etc.).

The values used to determine the CO2 setpoint are configured using either Tracer SC or the Rover service tool (refer to Figure 114, p. 163).

Space CO2 Low Limit

The space CO2 low limit (refer to Figure 114, p. 163) should be set equal to the outdoor CO2 concentration level because the CO2 level in the space cannot be less than the CO2 level of the outdoor air. Outdoor air usually has a CO2 concentration between 300 and 450 ppm. If the actual outdoor CO2 level is unknown, use the default value of 300 ppm.

Space CO2 High Limit

The space CO2 high limit (Figure 114, p. 163) should be set equal to the allowable indoor CO2 concentration level at the design conditions. Refer to Engineer’s Newsletter, volume 34-5, CO2-based, Demand-Controlled Ventilation for more information.

Tracer SC Setup for VAV boxes with communicated CO2 values

To set up a ventilation optimization strategy based on CO2 levels, you need to perform the following steps:

1. In Tracer SC, select Spaces from the left-hand navigation and click on a VAV box listed below the space where you want to set up this strategy.

2. Click Configuration.3. In the Ventilation section, look for the Space CO2 Concentration BAS point (refer to

Figure 115). By default this point is always out of service (indicated by ).4. Click the check box for this point and click actions... > place in service. The icon

disappears when the point is in service.5. Once in service, the VAV box will think that there are 400 ppm of CO2 in the space (which is the

current value for this point).

Figure 114. Ventilation and space CO2 setup in Rover



Optimization

6. Using Tracer TU, create a TGP2 program that reads the value from the actual CO2 sensor being used and writes it to this point (refer to Figure 116). This TGP2 program must be set to run no less than every 5 minutes. In this example TGP2 program, the Analog Value would be replaced by the point that contains the actual CO2 value (which may be wired to an MP580 or some other device).

7. Once created, download this program into the Tracer SC.

Important: The UC400 controller also supports a hardwired CO2 sensor. When using a hardwired sensor, it is not necessary to place the Space CO2 Concentration BAS point in service or in the TGP2 program described above.

Strategy #4: Scheduled Ventilation

Scheduled ventilation is based on an estimate of how many people are in a space at any given time. In Tracer SC, a schedule controls the operating mode of an analog value to indicate how many people are in the space at any given time. A TGP2 program calculates the outdoor air requirement (refer to TGP2 program “Ventilation_Calc.tgp,” p. 166).

Example: Classroom 101 requires a minimum of 48 cfm (22.60 L/s) of ventilation air to account for emissions from carpeting, furniture, etc. (Occupied Ventilation Standby setpoint). During Occupied hours, an additional 10 cfm (4.70 L/s) of ventilation air is required per person. The cfm requirements for Classroom 101 are shown in Table 15, p. 165

Figure 115. Space CO2 Concentration BAS point

Figure 116. CO2 Concentration BAS point TGP2 program



Optimization

.

Setup for scheduled ventilation:8. Create an analog value point named “Number of Occupants” (for this example, set a minimum

value of 0, a maximum value of 30, and a default value of 0).9. Create an analog schedule.10. Add events to the schedule for each scheduled change of occupancy. Schedule the value of the

event based on the information in Table 15 (refer to Figure 117, p. 165).

11. Add the analog value to the analog schedule.12. Create the TGP2 program (shown in Figure 118, p. 166) to control the Ventilation Setpoint BAS

point on the VAV box in classroom 101.

Note: To find the instance number of a device and the name of a point on that device, you can run a site commissioning report and look up the instance and point name in the report. You can also navigate to the device you want, click more details..., select the point and click configuration. The name, as it will appear in TGP2, and the instance number are available.

Table 15. Classroom 101 cfm requirements

Hours Number of Occupants OA Requirement (cfm (L/s))

8 AM - 9 AM 1 58 (27.40)

9 AM - 12 PM 24 288 (135.90)

12 PM - 1 PM 0 48 (22.60)

1 PM - 3 PM 24 288 (135.90)

3 PM - 5 PM 1 58 (27.40)

5 PM - 8 AM Unoccupied 0 (0)

Figure 117. Adding set analog values to the schedule



Optimization

Ventilation_Calc.tgp

This program (refer to Figure 118) calculates a minimum outdoor air requirement given the number of occupants in a space and the cfm per person.

Note: The values in this TGP2 program are for this example only. Modify the program to meet the specific needs of your building.

Considerations for using scheduled ventilation:

1. One multi-state schedule and one multi-state value are required for each zone using scheduled ventilation.

2. The multi-state schedule(s) must be updated when times or the number of people change.3. CO2-based demand controlled ventilation may be a better solution.

System Level Action

Conditioning outdoor air is expensive. To reduce costs, Trane has developed a strategy to minimize the amount of unconditioned outdoor air brought into the building while still meeting ASHRAE ventilation requirements. By reducing the amount of unconditioned outdoor air, the cost to ventilate the zones is minimized both at the air handler and in reheat at the VAV boxes. This strategy is known as ventilation optimization.

The ventilation optimization program in the Tracer SC VAS continually calculates the corrected outdoor airflow. This is defined as the minimum amount of outdoor air the AHU needs to deliver to the system as defined in ASHRAE 62.1 for single-path VAV systems.

To calculate the corrected outdoor airflow, VAS must obtain several pieces of flow data from its VAV members.• Measured primary airflow. The VAV property associated with this value is the “Nominal

Airflow Status” point.• Effective ventilation setpoint. The VAV property associated with this value is the

“Ventilation Setpoint” point.• Ventilation ratio. The VAV property associated with this value is the “Ventilation Ratio” point.

Figure 118. Ventilation_Calc.tgp2

In order to optimize ventilation at the VAS level, measure and control outdoor airflow, which means using Traq dampers on the air handler. Refer to “Design Considerations,” p. 12 for information on selecting air handlers.

BestPractice



Optimization

Note: Because some of this flow data can only be provided by the controllers, the ventilation optimization strategy requires the use of Trane controllers.

The example on the following pages describes how the ventilation optimization program works.

Figure 119 shows a scenario where an air handler supplies airflow to three zones, each equipped with a Trane-controlled VAV box. Each VAV box must supply a minimum amount of ventilation air, which is determined by the selected zone-level ventilation strategy discussed earlier in this section. Zone 1 needs 200 cfm(94.39 L/s), zone 2 needs 300 cfm(141.60 L/s), and zone 3 needs 200 cfm (94.39 L/s). The Tracer SC VAS determines the minimum outdoor air requirements for the system based on the needs of each of the zones.

Note: The ventilation optimization program ignores a VAV’s active ventilation setpoint at times even when it is a non-zero value (i.e., when the Heat/Cool Mode Status mode is Test, Calibration, Max Heat, or Off). The controller goes into test mode under a variety of situations, but most commonly during air valve overrides and during auto-commissioning.

Figure 119. Effective ventilation setpoints for each VAV box (shown in IP units)

VAV

VAV

Exhaust

200 cfm

AHU

zone 3

zone 2

zone 1

300 cfm

200 cfmVAV

Effective Ventilation Setpoint

UnconditionedOutdoor Air

Sup

ply

Air

Ret

urn

Air



Optimization

Figure 120 shows the measured primary airflow for each zone. This is the amount of air required to satisfy the temperature setpoints. In the example, zone 1 is delivering 400 cfm (188.80 L/s), zone 2 is delivering 900 cfm (424.80 L/s), and zone 3 is delivering 1000 cfm (471.90 L/s).

Figure 120. Measured primary airflow required for each zone (shown in IP units)

VAV

VAV

ExhaustAHU

zone 3

zone 2

zone 1

VAV


Sup

ply

Air

= 2

300

cfm

Ret

urn

Air

400 cfm

900 cfm

1000 cfm

Measured Primary Airflow



Optimization

The controller calculates a ventilation ratio for each zone by dividing the effective ventilation setpoint by the measured primary airflow (refer to Figure 121). Zone 1 needs 50% outdoor air, zone 2 needs 33% outdoor air, and zone 3 needs 20% outdoor air.

Because zone 1 requires a larger percentage of outdoor air than zones 2 or 3, it becomes the critical zone. As a result, the outdoor air dampers could be controlled to maintain a mixture of 50% outdoor air (1150 cfm (542.70 L/s)) in the supply (refer to Figure 122).

All three zones are now adequately ventilated; however, it supplies more outdoor air than is required by ASHRAE 62.1. The reason for this is that zones 2 and 3 are both receiving 50% outdoor air, which is more than they require.

Figure 121. Finding the critical zone (shown in IP units)

Figure 122. Uncorrected outdoor airflow (shown in IP units)

VAV

VAV

Exhaust

200 cfm

AHU


zone 3

zone 2

zone 1

300 cfm

200 cfmVAV

Sup

ply

Air

= 2

300

cfm

Ret

urn

Air

400 cfm

900 cfm

1000 cfm

Measured Primary Airflow Effective Ventilation Setpoint

= .33 (33%)

= .2 (20%)

= .5 (50%)

Critical Zone

= .5 (50%)

ExhaustAHU

UnconditionedOutdoor Air1150 cfm



Optimization

The ASHRAE 62.1 standard includes equations to calculate the amount of unconditioned outdoor air required (Vot) by accounting for the unused outdoor air in the return:

Vot = Vou / (1 + Xs – Zd)

where:

Vot = the outdoor airflow required at the system intake.

Vou = the “uncorrected” outdoor air intake flow.

Xs = the average fraction of outdoor air required.

Zd = the critical zone ventilation ratio.

Using the example above, the results would be:

As a result, the required amount of outdoor air obtained through the outdoor air dampers is reduced to 870 cfm(410.9 L/s)(Figure 123).

Once the ventilation optimization program calculates the corrected outdoor airflow value, it must be communicated as the minimum flow setpoint to the VAV air handler.

(with IP units) (with SI units)

Vou = 200 + 300 + 200 = 700 cfm

Xs = (200 + 300 + 200) / (400 + 900 + 1000)

or Xs = 0.304

Zd = 0.50

Vot = 700 / (1 + 0.304 – 0.50)

or Vot = 870 cfm

Vou = 94.4 + 141.6 + 94.4 = 330.4 L/s

Xs = (94.4 + 141.6 + 94.4) / (188.8 + 424.8 + 471.9)

or Xs = 0.304

Zd = 0.50

Vot = 330.4 / (1 + 0.304 – 0.50)

or Vot = 410.9 L/s

Figure 123. Corrected outdoor airflow (shown with IP units)

ExhaustAHU


870 cfm



Optimization

Sending the Minimum Flow Setpoint to the VAV Air Handler

If using an IntelliPak or AH540 air handler:

When you add the air handler to the VAS as an air handler member, Tracer SC VAS automatically controls the outdoor air minimumflow setpoint to the corrected outdoor airflow value at priority level 14.

If using an MP580/581 on the air handler with Traq dampers or outdoor air flow

monitoring:

• Tracer SC VAS calculates the corrected outdoor air flow setpoint and writes the value to the analog value point “VentOptOaSetpointCorrected|VAS-1”.

• The MP580/581 DAC profile does not support the nviMinOAFlowSP LonTalk variable; therefore, you must communicate the outdoor air minimum flow setpoint using a Tracer Summit analog variable in the MP580/581.

• Use the small TGP2 program in the Tracer SC (refer to Figure 126, p. 172) to read the VentOptOaSetpointCorrected|VAS-1 value in Tracer SC and write to the Tracer Analog Variable “Outdoor Airflow Setpoint” in the MP580/581 (refer to Figure 125).

Figure 124. VAS writing to the outdoor air minimum flow setpoint at priority level 14

Figure 125. Data flow for OA flow setpoint from Tracer SC VAS to the MP580/581

Tracer SC

VAS

TGP2

Reference

MP580/581

“ventOptOaSetpointConnected|VAS-1”Analog Variable(created by VAS)

“TrAV/3-Analog Var 03 (Summit)|dac/1”Analog Output

(created by Equipment)

Tracer SummitAnalog Variable

“OA Flow Setpoint”



Optimization

Setup

1. Program the MP580/581 using a DAC profile.

Important:All VAV air handlers controlled using MP580/581 controllers must be programmed using a DAC profile.

2. Program the MP580/581 to use a “Tracer Summit Analog Variable” for the Minimum OA Flow Setpoint.

3. Install the MP580/581 in the Tracer SC.4. Create the VAS in the Tracer SC5. Add the MP580/581 to the VAS as an air handler member.6. Create and download the outdoor air flow TGP2 program on the Tracer SC (using Tracer TU).

Ventilation Ratio Limits

In the example (p. 167 to p. 170), the amount of unconditioned outside air the air handler needed to supply was calculated to be 870 cfm (410.9 L/s) or approximately 37.8% of the total air supplied to the system. On a normal day, most air handlers can typically condition between 40 and 50% of outside air, so the outside air requirement is not a problem.

What if the air handler cannot condition the required percentage of outside air? Design engineers typically select an air handler with the capability of providing a maximum of 25% outdoor air at design. If the outdoor air temperature is extremely cold, the safeties on the unit may limit the amount of outdoor air the unit can bring in, the freeze stat may nuisance trip, or coils may freeze in the unit. If the outside air temperature is very hot, or humid, the air handler may not be able to sufficiently cool or dehumidify the air, resulting in overheated spaces and indoor air quality problems. In either case, the amount of outdoor air must be restricted and the VAV boxes made aware of this limitation.

Use Trane Pre-Packaged Solutions programs.Best

Practice

Figure 126. TGP2 program for OA air flow setpoint when using an MP580/581



Optimization

Ventilation Ratio Limit of the AHU

The AHU ventilation ratio limit of the air handler is set using the AHU Maximum Percentage of Outdoor Air point (VAS > Functions > Ventilation Optimization) (Figure 2, p. 178). This value prevents the VAS from requesting a higher AHU percentage of outdoor air (OA) than the AHU can provide to the supply air stream based on the capacity of the AHU and current outdoor weather conditions.

While this field limits the percentage of outdoor air the VAS requests from the air handler, it does not prevent the VAV boxes from asking for a greater percentage of outdoor air than the system can deliver (refer to “Ventilation Ratio Limit for each VAV” below).

Ventilation Ratio Limit for each VAV

The Ventilation Ratio Limit for each VAV works in conjunction with the Ventilation Ratio Limit of the AHU to provide two functions: • It minimizes the energy consumption of the VAV system.• It prevents the VAV box from asking for a greater percentage of outdoor air than the system can

deliver.

Minimizing energy consumption

Minimizing the total energy consumption in a VAV system requires a proper balance between the amount of energy applied at the air handler to condition the fresh outdoor air, and the amount of energy applied at the VAV box in the form of reheat (refer to Figure 129).

Use the default value of 40%. Best

Practice

Figure 127. Ventilation optimization AHU ventilation ratio limit

Figure 128. Ventilation optimization VAV ventilation ratio limit



Optimization

Note: As the percentage of outdoor air decreases, the VAV box must increase the total airflow to the space to maintain the ventilation ratio. This increase in airflow leads to over-cooling and, consequently, the need for reheat.

Limiting the critical zone outdoor air request

The VAV Ventilation Ratio Limit (now set in the SC editor using the “VAV Maximum Percentage of Outdoor Air Request) sets the maximum value that can be reported by the Ventilation Ratio Calc property of the VAV boxes to the VAS, preventing the critical zone VAV box from asking for a greater percentage of outdoor air than the system can deliver.

Example 1: Figure 130 shows the same system we used previously with different cooling loads. Zone 2 is now the critical zone, and its measured primary airflow is approaching the effective ventilation setpoint. The resulting calculated ventilation ratio of the critical zone is 75%, which exceeds the current Ventilation Ratio Limit for each VAV of 60%.

Figure 129. System energy consumption curve

% of Ventilation Air

Ene

rgy

Use

d (k

Wh)

50%

Low

High

Increases energy used inthe zone for reheat

Increases energy used inthe AHU for preheat, cooling, dehumidification

60%25% 75%

Based on energy analysis simulations, to minimize total system energy consumption, Trane recommends that the amount of outdoor air supplied to the critical zone be between 50% and 60% of the total airflow. The default value is 60%.

BestPractice



Optimization

Problem: If the critical zone is allowed to request 75% outdoor air, two things will occur:

1. The energy consumed by the VAV system will be higher than necessary because it will now be operating outside the optimal energy consumption range as shown in Figure 129 on page 174.

2. The zone will be under-ventilated, because the corrected outdoor air requirement of 1387 cfm(654.6 L/s) (50% of the total airflow) exceeds the Ventilation Ratio Limit of the AHU value, which is set at 40%. As discussed earlier in this section, the Ventilation Ratio Limit of the AHU restricts the amount of outdoor air the air handler can provide in the total supply airflow.

Solution: Set the Ventilation Ratio Limit of each VAV to 60% (default), which will do the following: • prevent the system from operating outside the optimal energy consumption range (refer to

Minimizing energy consumption on p. 173).• limit the ventilation ratio of the critical zone to a maximum value.

How the Ventilation Ratio Limit of each VAV is applied

1. Initially, each VAV box calculates the ventilation ratio and the VAS uses this information to determine the critical zone. In example 1, the ventilation ratio of 75% establishes zone 2 as the critical zone.

Figure 130. Example 1, VAV ventilation ratio limit (shown in IP units)

VAV

VAV

Exhaust

200 cfm

AHU


zone 3

zone 2

zone 1

300 cfm

200 cfmVAV

Sup

ply

Air

= 2

750

cfm

Ret

urn

Air

1350 cfm

400 cfm

1000 cfm

Total Air Flow Required for the zoneMin OA Requirement

= .2 (20%)

Critical Zone= .15 (15%)

= .75 (75%)

1387 cfm

1387 cfm of outdoor air (approximately 50%) exceeds the capacity of the air handler.



Optimization

Although the ventilation ratio of 0.75 is used to establish the critical zone, it cannot be used to determine the corrected percentage of outdoor air in the system supply (refer to the equations on p. 170) because the value exceeds the Ventilation Ratio Limit for each VAV (0.60).

When the critical zone requests a higher ventilation ratio than the Ventilation Ratio Limit for each VAV allows, the value for the Ventilation Ratio Limit for each VAV (60%= 0.60) replaces the ventilation ratio (0.75) of the critical zone.

2. The VAV box recalculates the total airflow required for the zone in order to satisfy the Minimum OA Requirement of the critical zone. Refer to “Zone Level Action,” p. 160 for details on calculating the ventilation requirement.

Figure 131. Determining the critical zone

Figure 132. Ventilation optimization VAV ventilation ratio

VAV

VAV

200 cfm

zone 3

zone 2

zone 1

300 cfm

200 cfmVAV

Sup

ply

Air

= 2

750

cfm

Ret

urn

Air

1350 cfm

400 cfm

1000 cfm


= .2 (20%)


= .75 (75%)

r.



Optimization

To satisfy the equation, the VAV box must increase the total airflow delivered to the Zone because the value for the Min OA Requirement cannot change.

Figure 133. Recalculating total airflow (shown in IP units)

(with IP units) (with SI units)

0.60 = 300 cfm/Total Airflow Delivered to Zone

Total Airflow Delivered to Zone = 300 cfm/0.60

Total Airflow Delivered to Zone = 500 cfm

0.60 = 141.60 L/s per Total Airflow Delivered to Zone

Total Airflow Delivered to Zone = 141.60 cfm/0.60

Total Airflow Delivered to Zone = 236.00 L/s

Figure 134. Example 2, Zone-affected minimum flow setpoints (shown in IP units)

VAV

zone 2

zone 1

300 cfm = 0.60 Ret

urn

Air

??? cfm

VAV

VAV

Exhaust

200 cfm

AHU


zone 3

zone 2

zone 1

300 cfm

200 cfmVAV

Sup

ply

Air

= 2

850

cfm

Ret

urn

Air

1350 cfm

500 cfm

1000 cfm


= .2 (20%)


= .60 (60%)

1084 cfm



Optimization

Using the equations discussed on p. 170, the corrected outdoor airflow at the air handler is now 1084 cfm (511.6 L/s), which is 38% of the total airflow and the zone is now properly ventilated with supply air containing a lower concentration of outdoor air.

Default Ventilation

The startup airflow setpoint is used during the initial air handler startup allowing time for the air system to stabilize.

The length of time the system uses this value is called the transitional delay, which is twice the value specified in the Reset Interval: field (refer to Step 4). When the Reset Interval expires, the system uses the corrected outdoor airflow setpoint (refer to “System Level Action,” p. 166 for a discussion on how the system calculates this value).

Ventilation Optimization Setup

To configure the Tracer SC VAS, follow these steps:

1. Select Systems > Variable Air Systems from the left-hand navigation. Select the specific VAS from the list, and then the Functions page. The Ventilation Optimization information is on the lower half of the page. Refer to Figure 135.

2. Verify that the Ventilation Optimization is Enabled (Currently list box).3. Set the startup airflow setpoint as determined by the best practice.4. Set a value in the Reset Interval: field (default is 15 min.). The reset interval indicates how often

(in minutes) the required system outdoor airflow is recalculated. 5. Save the VAS

ASHRAE 62.1 specifies an outdoor air rate of 0.06 cfm/ft2 (0.35 L/s per m2) for most spaces.

To calculate the startup airflow setpoint, multiply the (total square footage of the zone(s) being served by the air handler) x 0.06 cfm/ft2 (0.35 L/s per m2).

BestPractice

Figure 135. Ventilation optimization group

Use the following default values:• Ventilation Ratio Limit of the AHU = 40%• Ventilation Ratio Limit for each VAV = 60%

BestPractice



Optimization

Ventilation Optimization Status

The status group under Ventilation Optimization shows the current status of the ventilation optimization including three values that can be refreshed using the refresh button. They are:

Next ventilation reset in X minutes. This value shows the amount of time remaining until the next ventilation reset occurs.

Maximum VAV vent ratio. This is the maximum ventilation ratio reported from VAV boxes that are enabled for ventilation optimization reset.

Maximum vent ratio source. The name of the VAV box that reported the maximum ventilation ratio.

Ventilation Optimization Enhancement

The Vent_Ratio_Limit.TGP2 program may be used to reset the ventilation ratio limit value based on outside air temperature. To accomplish this, reference the associated analog outputs controlled by the Vent_Ratio_Limit.TGP2 program to the respective fields in the editor.

Example: To prevent the coils from freezing in an AHU on a building in St. Paul, MN, reset the ventilation ratio limit per the reset schedule in Table 16.

The ventilation ratio limit for the AHU is fixed at 25% when the outdoor air temperature is below 0°F or above 75°F, and fixed at 40% when the outdoor air temperature is between 50°F and 65°F (Figure 136). The ventilation ratio limit modulates from 25% to 40% between 0°F and 50°F and 65°F and 75°F.

Table 16. Ventilation ratio limit reset schedule

Outdoor Air Temperature 0°F 50°F 65°F 75°F

Ventilation Limit Ratio 25% 40% 40% 25%

Figure 136. FG_Ventilation ratio limit reset curve

0°F

20% Differential

AHU Limit

VAV Limit

25%

Outdoor Air Temperature

Ven

tilat

ion

Rat

io L

imit

40%

60%

50°F 65°F 75°F

The Ventilation Ratio Limit of each VAV should be set 20% higher than the Ventilation Ratio Limit of the AHU.Best

Practice



Optimization

Setup

1. Create two analog output points in Tracer SC.2. Reference the first analog output from the Ventilation Ratio Limit of the AHU: field in the VAS

editor.3. Reference the second analog output from the Ventilation Ratio Limit for each VAV: field in the

VAS editor.4. Control the operating mode of the analog outputs using the custom program

Vent_Ratio_Limits (refer to p. 180).5. Modify the CPL program Vent_Ratio_Limits to use the objects in your database.

PROGRAM Vent_Ratio_Limits

This routine calculates the ventilation ratio limit of the AHU and the ventilation ratio limit for each VAV based on the outdoor air temperature and air handler capacity. The ventilation ratio limit for the AHU ranges from a minimum of 25% to a maximum of 40% and is limited if the outdoor air temperature falls below 50°F or rises about 65°F. The corresponding ventilation ratio limit for each VAV is then calculated to be 20% higher than the ventilation ratio limit of the AHU.

Figure 137. Vent_Ratio_Limits.TGP2



Special Applications

This section describes enhancements to the basic VAS system to accommodate situations where more specific control is beneficial or required. • Dedicated ventilation systems. A separate outdoor air handling unit supplies ventilation air

to the building with VAV boxes controlling the ventilation airflow into various parts of the building. This section describes how to set up a basic dedicated ventilation system, including setting up the VAV box as a ventilation flow controller.

• Flow tracking. Maintains a positive or negative space pressure by controlling the airflow into and out of the space. This section describes how to set up a pair of VAV boxes to work together in a flow tracking application.

Dedicated Ventilation Systems

What is a Dedicated Ventilation System?

A dedicated ventilation system is designed to supply ventilation air to other air handlers within the building when the operating mode of any of the building’s Areas are Occupied or Optimal Stop.

Important: Do not use a dedicated ventilation system for Night Economizing as this is not a ventilation function

A dedicated ventilation system (refer to Figure 138, p. 182) consists of a dedicated outdoor air VAV air handler, ductwork, and either shutoff VAV boxes (no reheat) or VAV boxes (with electric reheat) configured for ventilation flow control (VFC).

Important: When using a VAV box equipped with electric heat as a VFC box, an auxiliary temperature sensor must be installed in the discharge air stream

Equipping the VAV box with electric heat allows it to pre-heat cool/cold outdoor air brought into a building for ventilation reducing the load on the other AHUs.

Important: Do not use VAV boxes with hot water reheat in a dedicated ventilation system, because there is no freeze protection built into the application.

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VFC boxes

In a dedicated ventilation system, the VAV boxes are configured for ventilation flow control (VFC boxes) one of three applications supported by the Tracer VV550/551 and the UC400 controller (Space Temperature Control and Flow Tracking Control are the other two). Use the Rover or Tracer TU service tool to configure the VAV controllers for VFC.

Figure 139, p. 183 shows the typical components installed on a VAV box with a VV550/551 or UC400 controller configured as a VFC box in a dedicated ventilation system.

Figure 138. Dedicated ventilation system

100%Outdoor Air

Dedicated Ventilation

mechanicalroom common

space

(4)

(16)

(1)

VAS 5

VAS 6

VAS 4

VAS 3

VAS 2

VAS 1

Floor 5

VFC AHUCSC (w/LCI-I)

( )

VAV(4)

VAV


space

(4)

(16)

(1)

Floor 4


( )

VAV(4)

VAV


space

(4)

(16)

(1)

Floor 3


( )

VAV(4)

VAV


space

(4)

(16)

(1)

Floor 2


( )

VAV(4)

VAV


space

(4)

(16)

(1)

Floor 1


( )

VAV(4)

VAV

AHU100% Outdoor Air Unit




Setting up a dedicated ventilation system

These instructions are based on the following example (refer to Figure 138, p. 182):Example: The 5-story Stone Enterprises building has a Self-Contained VAV system on each floor consisting of one VAV Commercial Self Contained (CSC) air handler (w/LCI-I) and 20 VAV boxes. A dedicated ventilation system, consisting of one air handler and 5 VAVs, provides 100% outdoor air to a mechanical room on each floor of the building.

1. Lay out the building

For simplicity, assume that each of the five floors has one tenant and one schedule. This allows us to create one Area per floor (including the mechanical room). Each Area has 17 VAV members: • 1 VAV box configured as a VFC box in the mechanical room • 16 VAV boxes serving the tenant spaces• 4 VAV boxes serving the bathrooms, hallways, and conference rooms and designated as

common space VAV boxes.

2. Install the VAVs and AHUs (in Tracer SC)

a. Install one variable volume air handler for the dedicated outdoor air handler (refer to “Install and Set Up the Variable Air Volume Equipment Types,” p. 73).

b. Install one variable volume air handler for each of the five floor air handlers (refer to “Install and Set Up the Variable Air Volume Equipment Types,” p. 73).

c. Install 105 VAV boxes (refer to “Select Members,” p. 77).

3. Create a VAS for the dedicated ventilation system

a. Create one VAV Air System for the dedicated ventilation system.

b. Assign the following members to the dedicated ventilation system VAS:

• One 100% outdoor air unit (AHU member)

• Five VAV boxes (VAV members, which are not designated as common space VAVs). These VAV boxes must be configured for Ventilation Flow Control.

• In VAS VAV Configuration, select each VAV box and include it in duct pressure optimization (select the check box).

Figure 139. VFC box

Flow Ring

Air Valve

Discharge TemperatureSensor (required with electric heat)

Electric Heat(optional)

Outdoor Airfrom AHU

Aux

VFC Box To Floor VAS

VAVcontroller




c. Verify that duct static pressure optimization is enabled in VAS Configuration.

d. Disable ventilation optimization for the dedicated ventilation system.

4. Create a VAS for each floor

In each floor VAS, add the VFC box as a ventilation member. The dedicated ventilation VAS monitors the operating mode of each floor’s VFC box. This provides a link between the dedicated ventilation VAS to each floor VAS. So if the VAS from any floor transitions from Unoccupied to Occupied, the dedicated VAS also transitions to the Occupied mode (refer to Figure 140).

a. Create one VAV Air Systems for each floor of the building (5 total). Refer to “Add the Area to an HVAC Schedule,” p. 108.

b. Assign the following members to each “floor” VAS:

• One air handler as the AHU member (CSC with LCI-I).

• 16 VAV boxes as VAV members

• 4 VAV boxes as VAV members (designated as common space members).

• One VFC VAV box as a ventilation member.

c. For each floor VAS verify ventilation optimization and duct pressure optimization check boxes are checked.

5. Set up the VAV controllers on the VFC boxes

Complete the following steps for each of the VFC boxes:

In TGP2, read the analog value of the VAS: “ventOptOaSetpointCorrectedRef” and write the value to the analog output of the VAV box: “VentilationSetpointRequestBAS”. Refer to Figure 138, p. 182.

Do not define any common spaces for a dedicated ventilation air system. If additional boxes are required to handle the minimum airflow of the supply fan, use TGP2 to override an additional VFC box.

BestPractice

Figure 140. VFC box as ventilation member of each Floor VAS

commonspace

(4)

AHU not shown

AHU not shown

AHU not shown

AHU not shown

(16)(1)VAS 6

Floor 5VASVFC

(16)

VAV(4)

VAV

commonspace

(4)(16)(1)

Floor 4AreaVFC

(16)

VAV(4)

VAV

commonspace

(4)(16)(1)

Floor 3VASVFC

(16)

VAV(4)

VAV




6. Service Tool Setup for VFC VAV boxes

a. If equipped with electric heat, enter the value for the minimum airflow required while the electric heat is ON (per the ship-with literature) using the appropriate service tool.

Note: Active airflow setpoint

The ventilation setpoint is used when reheat is not active. The Local Heat Minimum Airflow setpoint is used when reheat is active and it has a higher value than the Ventilation setpoint.

b. Set the Maximum Air Flow setpoint field equal to the value in the Occupied Ventilation field on the Configuration tab.

c. Set the Minimum Air Flow setpoint field equal to the value in the Occupied Standby Ventilation field on the Configuration tab.

d. If the VFC boxes are equipped with electric reheat, select the Configuration tab. Verify the Auxiliary Heat Control field is set to Enabled. Do not reference this field to another property.

Figure 141. Example TGP2 Program for Dedicated Ventilation

Steps “b” and “c” make the VFC boxes behave like other VAV boxes in the system, which makes air balancing easier.

The value for both the Occupied Ventilation setpoint and the Occupied Standby Ventilation setpoint should have been determined by the project engineer and filled in on the Controller Flow Settings Worksheet (refer to “Appendix A: Controller Flow Settings Worksheet,” p. 239).

BestPractice




7. Set up the VAV AHU controller for the dedicated VAS

a. Add the VAV AHU to the dedicated VAS as an AHU member.

b. When using MP580/581s, the DAC profile must be active and the DAC Profile - nviDuctStaticSP variable must be used in the TGP2 programming.

8. Set up the VAV AHU controller for each floor VAS

a. Add the VAV AHU to the floor’s VAS as an AHU member.

b. When using MP580/581s, the DAC profile must be active and the DAC Profile - nviDuctStaticSP variable must be used in the TGP2 programming.

9. Create Areas

Create Areas and add VAV boxes.

a. Create five Areas (one Area for each floor of the building). Refer to “Set Up Areas,” p. 75.

b. For each floor Area, assign the 16 VAV boxes in the tenant space as "Heating/Cooling" members.

10. Create Schedules

a. Create one schedule for each Area. Refer to “The Schedule Times page appears (Figure 68). The current date displays as the default Start Date in the Specify Effective Dates group. Choose the Start Date and End Date for your HVAC schedule.,” p. 111.

b. Assign the Areas as members of the appropriate schedule.




Flow Tracking

Flow tracking, commonly applied in hospitals and labs, is used to maintain a positive or negative pressure in a space relative to adjoining spaces. Space pressure is maintained by controlling airflow into and out of a space using two VAV boxes (a space temperature control box on the inlet and a flow tracking box on the outlet).

Maintaining Positive Space Pressure

Positive space pressure is typically maintained in rooms where external contaminants must be prevented from entering. A surgical suite is a good example.

To positively pressurize a space, more air must flow in than is allowed to leave. (refer to Figure 142). The inlet VAV box controls the amount of air allowed into the space based on temperature. The outlet VAV box “tracks” the incoming airflow and limits the amount of air leaving the space using a fixed offset (i.e., 100 cfm less than the inlet VAV box). The difference in airflow results in a positive space pressure.

Maintaining Negative Space Pressure

Negative space pressure is typically maintained in rooms where internal contaminants must be prevented from leaving. A lab testing infectious diseases is a good example.

To negatively pressurize a space, more air must flow out than is allowed to enter. (refer to Figure 143). The inlet VAV box controls the amount of air allowed into the space based on temperature. The outlet VAV box “tracks” the incoming airflow and allows more air to leave the space using a fixed offset (i.e., 100 cfm more than the inlet VAV box). The difference in airflow results in a negative space pressure.

Figure 142. Positive pressure flow

Flow Tracking Space

VAVReturn AirVAV

Supply Air

Inlet Outlet

Positive pressure air flow

Flow is300 cfm Flow is

200 cfm

Space TempSensor

Space TempControl Box

Flow TrackingBox




How to Set It Up

Setup for a flow tracking system is the same as setting up a standard VAV air system (refer to “Tracer SC Application Setup for Variable Air Systems,” p. 72 for detailed information). The space temperature control box on the inlet to the room is just like a normal VAV box described throughout this manual. The only difference is the setup required for the additional VAV boxes in each temperature-controlled space that track the incoming airflow.

Set up the flow tracking boxes (when using VV550/551 controllers)

For each flow tracking VAV box:Use the Rover service tool (in the active mode) to bind:

This binding communicates the airflow through the space temperature control VAV box to the flow tracking VAV box.

1. Set the Tracking Offset

• positive value for negative room pressure

• negative value for positive room pressure2. Set the cooling maximum and minimum airflow setpoints as follows:

Positive room pressure (Negative Flow Tracking Offset)

• Maximum Air Flow Setpoint = Main Box Max Flow - Tracking Offset value

• Minimum Air Flow Setpoint = Main Box Min Flow - Tracking Offset valueNegative room pressure (Positive Flow Tracking Offset)

• Maximum Air Flow Setpoint = Main Box Max Flow + Tracking Offset value

• Minimum Air Flow Setpoint = Main Box Min Flow + Tracking Offset value

Figure 143. Negative pressure flow

Flow Tracking Space

VAVExhaust Air

VAVSupply Air

Inlet Outlet

Negative pressure air flow

Flow is200 cfm Flow is

300 cfm

Space TempControl Box

Flow TrackingBox

Space TempSensor

nvoAirFlow

Binding

nviAirFlowSetpt




Note: The Rover service tool will not allow the setpoints to be less than 10% of nominal flow because the transducer used to measure the air flow requires a nominal flow greater than 10% of the design airflow.

Set up the flow tracking boxes (when using UC400 controllers)

We are assuming the UC400 has not been configured at the factory as a flow tracking VAV box controller. The procedure below describes the tasks required to configure a UC400 in the field for flow tracking.

For each flow tracking VAV box:

1. Connect to the UC400 using a USB direct connection and launch the Tracer TU service tool.

Note: You can also connect via the IMC bus, but the USB direct connection is recommended.2. Select Utilities > Equipment and click the 4. Configuration tab. The VAV and vestibule

control page appears (refer to Figure 144).

3. In the Application Selection section, select Flow Tracking in the Profile list box.4. In the Equipment Options section, select the appropriate Box Size and Air Damper Opens

parameters for the VAV box being configured.5. Click Save.6. Click the 2. Setup Parameters tab.

Figure 144. FG_TitleAcrossCol




7. Set the Air Flow Offset value.

• use a positive value for negative room pressure

• use a negative value for positive room pressure

8. Install the UC400 into the Tracer SC.

Important: Flow tracking boxes cannot be assigned as members of an Area or VAS.

Note: The space temperature control boxes will be assigned to a VAS as per normal best practices.

9. In Tracer SC, create an analog input to read the air flow (cfm or L/s) coming from the space temperature control VAV box.

Important: Creating an analog input allows you to set the update interval to a defined frequency (e.g., 10 seconds).

10. In Tracer TU, create a TGP2 program that writes the value from the analog input created in Step 9 previously and writes it to the Air Flow Setpoint BAS point in the flow tracking VAV box (refer to Figure 146, p. 191).

Figure 145. Setup Parameters page in Tracer TU




Figure 146. Flow tracking setup.

Tracer SCUC400 on a

Flow Tracking VAV Box

UC400 on a


VAV Box

Discharge Air Flow Value Referenced by

Analog Input

TGP2 Program Reads

the AI and writes

the value to

Air Flow Setpoint BAS



Maintenance

This section gives some ideas on:

• How to use auto-commissioning. Using the auto-commissioning tool to generate a report and isolate non-performing or under-performing VAV boxes, which can save time in troubleshooting and can give the customer some indication of the overall condition of their system.

• Manual output testing.

Auto-commissioning

Important: Detailed information on initiating and using auto-commissioning is available in the section titled “Preliminary Checkout for BACnet Communication Links,” p. 144.

Auto-commissioning provides a means to quickly evaluate the condition of the VAV air system by putting each VAV box through a special operating sequence as part of a routine maintenance program. Figure 147 presents an example of an auto-commissioning report.

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Maintenance

Manual Output Testing for VV550/551 Controllers

The manual output test (see Table 17, p. 194) verifies output and end device operation. Use it to verify output wiring and actuator operation without using the Rover service tool. Also use it during air balancing or water balancing.

The manual output test terminates when it has advanced completely through the test sequence or when the controller times out as a result of remaining in a single step for one hour. The outputs are not subject to minimum times during the test sequence. However, the test sequence only permits one step per second, which enforces a minimum output time.

All diagnostics other than the following are ignored during manual test:

• Ventilation flow control, freeze protection (low discharge air temperature)

• Low airflow diagnostic (this diagnostic will prevent local electric reheat)

Figure 147.Auto-commissioning sequence results



Maintenance

The procedure for testing is:

1. Press and hold the Test button on the VAV box controller for at least three seconds. The green status LED turns Off, confirming the Test button was pressed.

2. Release the Test button to start the manual output test. The manual output test is in step one. The green status LED is blinking in one of two patterns. If the green status LED blinks once, no diagnostics are present. If the green status LED blinks twice, diagnostics are present.

3. Press the Test button (no more than once per second) to advance through the test sequence. Test steps are not skipped. For example, if the unit does not have Heat 3, advancing to step 6 has no effect, but you still must advance to step 6 before advancing to step 7.

Alternatively, the service override mode enables the Rover service tool to override all outputs over the communications network. This mode is useful for water balancing, air balancing, test, and commissioning. The implementation mimics the manual output test.

Table 17. Manual Output Test

Step(a)Air Valve

CloseAir Valve

OpenHeat 1/ Water

Valve CloseHeat 2/ Water

Valve OpenHeat 3 / Fan

On/Off

1. Off(b) Off Off Off Off Off/Off

2. Air Valve Open(c) Off Off Off Off Off/Off

3. Air valve stops opening, fan turns on

Off Off Off Off Off/On

4. Heat 1 turns on/water valve closes

Off Off On Off Off/On

5. Heat 1 turns off, Heat 2 turns on/water valve opens

Off Off Off On Off/On

6. Heat 2 turns off, Heat 3 turns on/water valve closes

Off Off Off/On Off On/On

7. Heat 3 turns off, air valve closes, fan turns off

On Off Off Off Off/Off(d)

8. Exit(e)

(a) The manual output test won't start if the controller has an invalid unit configuration(b) On activating the manual output test function, all outputs are turned Off or closed. The green status LED blinks in a one blink pattern during the manual

output test if no diagnostics are present. The green status LED blinks in a two-blink pattern during the manual output test if a diagnostic is present.(c) At the beginning of step 2, the controller attempts to reset all diagnostics. The low airflow diagnostic prevents local electric reheat from energizing. A

ventilation flow controller with a freeze protection active diagnostic will not run the manual output test.(d) A series fan stays On until the air valve is closed.(e) After the last step, the test sequence performs an exit. This initiates a reset and attempts to return the controller to normal operation.



Maintenance

Initiating the Test

To initiate the manual output test for an air handler or VAV box from the Rover service tool

1. Click the Test tab to open the Manual Output Test page.

2. Click Start to conduct a manual output test. Rover will initiate each of the outputs identified for the air handler (open and close dampers, valves, etc.)

3. As each output test is completed, click Next Step to advance to the next output test. If possible, be close to the air handler or have someone close enough to observe whether each output test is successful.

Important: Remember that not all the safeties are enabled during the manual output test, so be careful. The following safeties ARE enabled during the manual output test:

• Duct static pressure high limit

• Low supply fan airflow

• Low temp detect

• Unit shutdown

Manual Output Testing for UC400 Controllers

The UC400 does not have a manual output test built into the product.



Troubleshooting

This section provides information for troubleshooting the system after installation and during routine maintenance, which includes:• Scenarios outlining the proper sequence of operation for the system under specific conditions.• How to isolate problem VAV boxes and remove them from the VAS until they’re fixed.• Charts for both the VAV box and air handler equipment showing the input received from the

SC, the output sent over the network, and the expected result at the device.

Make sure to follow the best practices outlined in previous sections as you find and fix problems in the VAV Air System.

Note: While the SC supports other manufacturers equipment, the sequences in this section are written for Trane equipment only.

Sequences of Operation for Standard Operating Modes

The following common applications have a defined sequence of operation when working within the confines of a Tracer SC VAS:• Normal start• Optimal start• Humidity pull-down• Unoccupied• Optimal stop• Unoccupied heat/cool• Night purge• Unoccupied dehumidify• Unoccupied humidify• Timed override• Comm Loss

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Troubleshooting

General Assumptions

For the following scenarios to work properly, the assumption is the system is set up a certain way and some basic best practices have been followed. The following list summarizes those general settings and best practices. Where there are assumptions specific to a scenario, they are listed at the beginning of that particular scenario.

Scheduling

Each Area is a member of an HVAC schedule.

Area

• Area Heat/Cool Input: = Auto

• Reference the following fields on the Area Configuration page:

– Reference the Space Temperature Sensor field to the pre-defined referencer for average space temperature.

– Reference the Space Humidity Sensor field to the humidity sensor installed within the Area.

– Reference the Outdoor Air Temperature Sensor field to the pre-defined referencer for the Facility Outdoor Air Temperature.

– Reference the Outdoor Air Humidity Sensor field to the pre-defined referencer for the Facility Outdoor Air Humidity.

• Each VAV box should be defined as a Heating/Cooling Member Type (regardless of whether the VAV box has the capability to provide heat).



Troubleshooting

• Each VAV box should have the desired functions enabled on the Member Configuration page.

VAV box

All of these items are configured using the service tool (either TU or Rover).• Configured for space temperature control.• Auto calibrate is enabled (check box IS selected)(applies to VV550/551 controllers only).• Star and double star (*/**) is not enabled (check box is NOT selected)(applies to VV550/551

controllers only).• auto changeover setpoint = 80°F.

VAS

• All of the VAV boxes are members—both normal and common space VAVs.• A variable volume air handler is the AHU member.• AHU Startup Delay = 2 min.• Common space shutdown delay = 5 min.• On the VAV Box Configure Members page, select which functions each VAV box will participate

in and whether the VAV box is a common space VAV box.



Troubleshooting

AHU Object

• Create a TGP routine to read the VAS average space temperature and send it to the air handler’s space temperature VAS.

Air Handler

• Configured as a VAV.• The Space Temperature BAS, on the air handler’s Configuration page (Sensors sections), is in

service. To place this in service:

1. Select the Space Temperature BAS check box.2. Click actions....3. Select place in service from the menu.



Troubleshooting

Optimal Start (Cooling Mode)

The system goes into this mode when the Area space temperature is warmer than the Area occupied cooling setpoint, it is prior to the occupied start time, and there is an Optimal window defined in Scheduling and the current time is within that time window.

Assumptions

This sequence of operation assumes the following settings are in place (beyond the general assumptions stated at the beginning):• Area Heat/Cool mode status = Cooling• Area is part of an HVAC schedule and Optimal Stop/Start is enabled (check box is selected)• An Optimal window is created in the HVAC schedule.


The following steps occur in the order shown during Optimal Start mode in a cooling only scenario.

Where it’s happening What it’s doing

Tracer SC(Software)

Unit Controller(Hardware) Operation Sequence

Scheduling 1. Scheduling and Area are coordinating Optimal Start.

Area 2. Area decides how early to enable the system based on the Area setpoint for the cooling mode (Calculated Occupied Cooling Setpoint), the space temperature (Space Temperature Sensor), and the optimal cooling start rate (startupcoolrate).

3. At the startup time determined in the previous step, controls the operating mode of all cooling only and heating/cooling VAV members to Optimal Start at the Area priority level.

4. Ventilation and heating members are Unoccupied or disabled.

Note: Refer to “Appendix E: Equipment Response to Operating Modes,” p. 245

VAV object 5. The operating mode controls the following values to the VAVs at the Area priority level:

• Occupancy Request = Occupied

• Heat Cool Mode Request = Morning Warm-up or PreCool (each VAV box Heat Cool mode request is determined by comparing its space temperature to its space temperature setpoint (the Space Temperature Setpoint BAS value is located on the Configuration page (select equipment > configure)). If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.)

Note: The local space temperature setpoint (thumbwheel) is not used to determine the Heat Cool Mode Request for optimal start.



Troubleshooting

VAV box 6. The VAV box receives the following values from the VAV object:


• Heat Cool Mode Request = Morning Warm-up or PreCool (based on Step 5).7. The VAV box damper modulates to maintain the active space temperature

setpoint.8. The VAV box heating or cooling minimum airflow is based on the heat or cool

control action of the VAV box.

• Heating control action: If the source temperature is above the auto changeover setpoint.

• Cooling control action: If the source temperature is below the auto changeover setpoint minus 10°F.

Note: When the AHU starts, the discharge air might be hot, but it should cool as the AHU ramps up.

9. Reheat and parallel fans are disabled if the VAV box is in Precool.

VAS 10. VAS detects that the operating mode of its VAV members and:

• controls the operating mode of common space VAV members to Optimal Start at the VAS priority level.

• controls the operating mode of the VAV air handler members to Optimal Start at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).

• AHU Heat Cool Mode Request = Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint (located on the Configuration page of the VAS). If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.

11. Ventilation functions are disabled.

AHU

object

12. The operating mode controls the following values to the AHU at the VAS priority level:

• Occupancy Request = Occupied• Heat Cool Mode Request = Morning Warm-up or PreCool (based on Step 10).• Minimum OA Damper Position = 0%• Outdoor Air Flow Setpoint = 0 (cfm or L/s)• Economizer Enable = Release

AHU 13. The AHU receives the following values from the VAV AHU object:


14. The AHU begins producing cool air(b).

(a) The length of this delay is adjustable. This is located on the Systems > VAS > Configuration page. Set the time in the Air Handler Startup Delay field.

(b) There may be a time delay here depending on the AHU type.


Tracer SC(Software)

Unit Controller(Hardware) Operation Sequence



Troubleshooting

Optimal Start (Heating Mode)(Central Heat Used/Local Heat Not Used or Not Present)

The system goes into this mode when the Area space temperature is colder than the Area occupied heating setpoint (minus 1°F to transition), it is prior to the Occupied start time, and there is an Optimal window defined in Scheduling and it is within that time window. Additionally, there is a heat source in the AHU with no local heat source in the VAV boxes (or the local heat source is not being used).

Typical Example: The Area space temperature is 65°F and it needs to warm it up so it gets to 72°F just as the building is Occupied at 8:00 AM. So Warm-up begins at 7:00 AM. The air handler is configured with gas heat and the VAV boxes are configured with electric heat. It is most cost effective to use the gas heat for Warm-up, so the auxiliary electric heat in the VAV box is disabled during Warm-up.

Assumptions

This sequence of operation assumes the following settings are in place:• Area Heat/Cool mode status = Heating• Area is part of an HVAC schedule and Optimal window is defined.• An Optimal window is created in the HVAC schedule.• The check box for “Allow VAVs to use auxiliary heat at night” is NOT selected on the Tracer SC

VAS configuration page.


The following steps occur in the order shown during Optimal Start mode in a heating with central heat and no local heat scenario.


Tracer SC

(Software)

Unit Controller(Hardware)

Operation Sequence


Area 2. Area decides how early to enable the system based on the Area setpoint for the heating mode (Calculated Occupied Heating Setpoint), the space temperature (Space Temperature Sensor), and the optimal heating start rate (startupheatrate).

3. At the startup time determined in the previous step, controls the operating mode of all heating only and heating/cooling VAV members to Optimal Start at the Area priority level.

4. Ventilation members are disabled.




Troubleshooting


• Heat Cool Mode Request = Morning Warm-up or PreCool or Max Heat (each VAV box Heat Cool mode request is determined by comparing its space temperature to its Space Temperature Setpoint BAS value. If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.)


• The Heat Cool Mode Request is Max Heat if the AHU reports that it is in the constant volume fan mode.

• Occupancy Request = Occupied6. The VAS controls the Auxiliary Heat Control point to Disabled at the VAS priority

(refer to Step 12).

VAV Box 7. The VAV box receives the following values from the VAV object:


• Heat Cool Mode Request = Morning Warm-up or PreCool or Max Heat (based on step 5).

8. If in Max Heat mode, the VAV object opens its damper to the Maximum Heat Airflow setpoint.

9. If not in Max Heat, the VAV box damper modulates to maintain the active space temperature setpoint. The VAV box heating or cooling minimum airflow is based on the heat or cool control action of the VAV box.




• Reheat and parallel fans are disabled if the VAV box is in Precool. 10. The VAV box also receives the following value from the VAS (refer to Step 5

above).

• Auxiliary Heating Enabled = Disable (refer to assumption 5 on p. 202).


Tracer SC

(Software)


Operation Sequence



Troubleshooting


• controls the operating mode of the common space VAV members to Optimal Start at the VAS priority level.



12. The VAS also controls the auxiliary heat at all the VAV boxes, including the common space VAV boxes, by sending the following value to the VAV object:

• Auxiliary Heating Enabled = Disable (refer to assumption 5 on p. 202).13. Ventilation functions are disabled.

AHU

object

14. The AHU receives the following values from the VAV AHU object:


• Heat Cool Mode Request = Morning Warm-up or PreCool (based on Step 11).

• Minimum OA Damper Position = 0%

• Outdoor Air Flow Setpoint = 0 (cfm or L/s)

• Economizer Enable = Release

AHU 15. The AHU receives the following values from the AHU object:


• Heat Cool Mode Request = Morning Warm-up or PreCool.



• Economizer Enable = Release16. The AHU begins supplying hot or neutral air(b) based on the active space

temperature it receives from Tracer SC(c) and the VAS Startup Setpoint.

• Active space temperature is below the VAS Startup Setpoint then the AHU supplies Hot air (if the air handler is running in the constant volume mode, it will report Max Heat to the VAS. The VAS then controls the Heat/Cool Mode Request of all the VAV members to Max Heat at the VAS control priority level.)

• Active space temperature is above the VAS Startup Setpoint then the AHU supplies Cold or Neutral air


(b) There may be a time delay here depending on the AHU type.(c) There are several choices available for this value. The first choice is probably the VAS average space temperature with the second

choice being the VAS minimum space temperature.


Tracer SC

(Software)


Operation Sequence



Troubleshooting

Optimal Start (Heating Mode)(Local Heat with a Central Fan)

The system goes into this mode when the Area space temperature is colder than the Area occupied heating setpoint (minus 1°F to transition), it is prior to the Occupied start time, and there is an Optimal window defined in Scheduling and it is within that time window. Additionally, there is little or no heat source in the AHU with a local heat source in the VAV boxes.

Typical Example: The Area space temperature is 65°F and it needs to warm it up so it gets to 72°F just as the building is Occupied at 8:00 AM. So Warm-up begins at 7:00 AM. The air handler has no heat and the VAV boxes are configured with hot water reheat.

Assumptions

This sequence of operation assumes the following settings are in place:• Area Heat/Cool mode status = Heating• Area is part of an HVAC schedule and Optimal window is defined.• An Optimal window is created in the HVAC schedule.• The check box for “Allow VAVs to use auxiliary heat at night” is selected on the Tracer SC VAS

configuration page.


The following steps occur in the order shown during Optimal Start mode in a heating with local heat and a central fan scenario.


Tracer SC

(Software)

Unit Controller

(Hardware) Operation Sequence


Area 2. Area decides how early to enable the system based on the Area setpoint for the heating mode (Calculated Occupied Heating Setpoint), the space temperature (Space Temperature Sensor), and the optimal heating start rate (Optimal Start Heating Rate).

3. At the startup time determined in the previous step, controls the operating mode of all heating only and heating/cooling VAV members to Optimal Start at the Area priority level.



Troubleshooting



• Heat Cool Mode Request = Morning Warm-up or PreCool or Max Heat

• Morning Warm-up or PreCool is determined by comparing the space temperature of the Area equipment members to the setpoint sent to the unit by the Tracer SC Space Temperature Setpoint BAS point. If the space temperature is above the setpoint, the Tracer SC sends PreCool. If the space temperature is below the setpoint, the Tracer SC sends Morning Warm-up.




• Heat Cool Mode Request = Morning Warm-up or PreCool or Max Heat (based on Step 4).






• Reheat and parallel fans are disabled if the VAV box is in Precool. 8. The VAV box also receives the following value from the VAS (refer to Step 10).

• Auxiliary Heating Enabled = Enable (value is 100)(refer to assumption 4 on p. 205).


Tracer SC

(Software)

Unit Controller




Troubleshooting


• controls the common space VAV members operating mode to Optimal Start at the VAS priority level.



10. The VAS also controls the auxiliary heat at all the VAV boxes, including the common space VAV boxes, by sending the following value to the VAV object:• Auxiliary Heating Enabled = Enable (refer to assumption 4 on p. 205).



AHU object 12. The AHU receives the following values from the VAV AHU object:











• Economizer Enable = Release14. The AHU begins supplying hot or neutral air(b) based on the heat/cool mode

request it receives from Tracer SC.




Tracer SC

(Software)

Unit Controller




Troubleshooting

Humidity Pull-down

The system goes into this mode when the Area space humidity is higher than the Area occupied humidity setpoint, it is prior to the occupied start time, and there is an Optimal window defined in Scheduling and it is within that time window.

Assumptions

This sequence of operation assumes the following settings are in place (beyond the general assumptions stated at the beginning):• Area Heat/Cool mode status = Cooling• Area is part of an HVAC schedule and Humidity Pull-down is enabled (check box is selected)• An early start limit must be set (greater than 0 minutes) that defines the earliest time that a

Humidity Pull-down event can occur.• An Optimal window is created in the HVAC schedule.


The following steps occur in the order shown during Humidity Pull-down mode in a cooling only scenario.


Tracer SC

(Software)

Unit Controller


Scheduling 1. Scheduling and Area are coordinating Humidity Pull-down.

Area 2. Area decides how early to enable the system based on the Area setpoint for the cooling mode (Occupied Humidity Setpoint), the space humidity (Space Humidity Sensor), and the humidity pull-down rate (Humidity Pulldown Rate).

3. At the startup time determined in the previous step, controls the operating mode of all cooling only and heating/cooling VAV members to Humidity Pull-down at the Area priority level (if they have dehumidification enabled).





• Heat Cool Mode Request = Morning Warm-up or PreCool (each VAV box Heat Cool mode request is determined by comparing its space temperature to its Space Temperature Setpoint BAS value (located on the Configuration page of the equipment). If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.)




Troubleshooting

VAV box 6. The VAV box receives the following values from the VAV object:


• Heat Cool Mode Request = Morning Warm-up or PreCool (based on Step 5).7. The VAV box damper modulates to maintain the active space temperature

setpoint.8. The VAV box heating or cooling minimum airflow is based on the heat or cool

control action of the VAV box.




9. Reheat and parallel fans are disabled if the VAV box is in Precool.


• controls the operating mode of the common space VAV members to Humidity Pull-down at the VAS priority level.

• controls the operating mode of the VAV air handler members to Humidity Pull-down at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).

• AHU Heat Cool Mode Request = Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint (located on the Configuration page). If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.


AHUobject

12. The operating mode controls the following values to the AHU at the VAS priority level:



• Occupancy Request = Occupied• Heat Cool Mode Request = Morning Warm-up or PreCool.• Minimum OA Damper Position = 0%• Outdoor Air Flow Setpoint = 0 (cfm or L/s)• Economizer Enable = Release

14. The AHU begins producing cool air(b).




Tracer SC

(Software)

Unit Controller




Troubleshooting

Normal Start

The best practice is to use Optimal Start. However, if not using Optimal Start, the Normal Start works as described here. The ventilation functions in both the VAV box and the air handler are enabled during a Normal Start, which is the major difference between a Normal Start and an Optimal Start, where ventilation functions in both the VAV box and the AHU are disabled.

Assumptions

This sequence of operation assumes the following settings are in place:• There is no Optimal window defined in the HVAC schedule for this Area, or the current time has

reached the start of the schedule.• The schedule must be an HVAC schedule.

Sequence of Operation.

The following steps occur in the order shown during Normal Start mode.


Tracer SC

(Software)

Unit Controller


Scheduling 1. The schedule tells Area to go Occupied.

Area 2. Area controls the operating mode of all VAV members to Occupied at the Area priority level.



• Heat Cool Mode Request = Release




Note: The VAV box Heat/Cool mode is determined by the priority array, where the highest level mode (lowest number) is applied when control is released (e.g., a TGP program may also be controlling the Heat/Cool mode).


• controls the operating mode of the common space VAV members to Occupied at the VAS priority level.

• controls the operating mode of the VAV air handler members to Occupied at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).




Troubleshooting

AHU object 6. The AHU receives the following values from the VAV AHU object (at the VAS priority level):



• Minimum OA Damper Position = Release

• Outdoor Air Flow Setpoint = Release


AHU 7. The AHU receives the following values from the AHU object (at the VAS priority level):








Tracer SC

(Software)

Unit Controller




Troubleshooting

Optimal Stop

Optimal stop is a scheduled function, but it is also a temperature-based function of Area. Optimal stop is the process of efficiently stopping the mechanical heating or cooling in advance of the space going into an Unoccupied mode. Because this is an Occupied condition, the air handler and fan continue to run and the outdoor air damper is set to allow minimum outdoor air into the air handler.

Assumptions

This sequence of operation assumes the following settings are in place:• Area is part of an HVAC schedule and Optimal Stop/Start is enabled (check box is selected)• An Optimal window is created in the HVAC schedule.


The following steps occur in the order shown during Optimal Stop mode.


Tracer SC

(Software)

Unit Controller


Scheduling 1. Scheduling and Area are coordinating Optimal Stop.

Area 2. Area determines the actual time to control the operating mode of VAV boxes to Optimal Stop based on the space temperature sensor, the occupied cooling/heating setpoint plus/minus 2°F (1.1°C), and the associated optimal stop rate.

3. At the time determined in the previous step, Area controls the operating mode of all VAV members to Optimal Stop at the Area priority level.

4. Ventilation members are enabled.


VAV object 5. The operating mode controls the following values to the VAVs at the the Area priority level:

• Occupancy Request = Standby


VAV Box 6. The VAV box receives the following values from the VAV object (at the VAS priority level):

• Occupancy Request = Standby

• Heat Cool Mode Request = Release7. The VAV box damper modulates to maintain the standby space

temperature setpoint.8. Ventilation functions are enabled.



Troubleshooting

VAS 9. VAS detects that the operating mode of its VAV members has changed and:

• controls the operating mode of the common space VAV members to Optimal Stop at the VAS priority level.

• controls the operating mode of the VAV air handler members to Optimal Stop at the VAS priority level.

10. Ventilation functions are enabled.

AHU object 11. The AHU object sends the following values to the AHU (at the VAS priority level):











• Economizer Enable = Release13. The AHU behaves as it does when Occupied.


Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied

Assumptions

This sequence of operation assumes the following settings are in place:• An HVAC schedule is created, which defines Occupied and Unoccupied times.


The following steps occur in the order shown during Unoccupied mode.


Tracer SC

(Software)

Unit Controller


Scheduling 1. The HVAC schedule tells Area to go Unoccupied.

Area 2. Area controls the operating mode of all VAV members to Unoccupied at the Area priority level.



• Occupancy Request = Unoccupied


VAV Box 5. The VAV box receives the following values from the VAV object (at the Area priority level):


• Heat Cool Mode Request = Release6. It auto-calibrates on the transition from Occupied to Unoccupied.7. It uses its unoccupied setpoints(a).8. Ventilation functions are disabled.9. It disables local heat for all VAVs depending on the VAS settings.


• controls the operating mode of the common space VAV members to Unoccupied at the VAS priority level. (b)

• controls the operating mode of the VAV air handler members to Unoccupied at the VAS priority level.

11. Ventilation functions are enabled.12. The VAS also sends the following command to the VAV object.

• Auxiliary Heat Control Request = Enabled (value is 100) (The check box for “Allow VAVs to use auxiliary heat at night” is selected on the Tracer SC VAS Configuration page).



Troubleshooting

AHU object 13. The AHU object sends the following values to the AHU (at the VAS priority level):


• Heat Cool Mode Request = Off


• Outdoor Air Flow Setpoint = 0

• Economizer Enable = Disabled






• Economizer Enable = Disabled15. The AHU is Off.

(a) The best practice for this may vary depending on the VAV box/heat type.(b) Does not occur until the shutdown delay expires.


Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied Heating/Cooling—Cooling Mode1 The hot Sunday in Phoenix scenario #1

Assumptions

This sequence of operation assumes the following settings are in place:• The HVAC schedule is unoccupied• The VAV box unoccupied cooling setpoint should be set higher than the Area unoccupied

cooling setpoint.


The following steps occur in the order shown during Unoccupied Heating/Cooling mode when cooling.

1 The industry sometimes refers to this function as the Night Setback mode


Tracer SC

(Software)

Unit Controller


Scheduling 1. The HVAC schedule is unoccupied.

Area 2. The Area operating mode is Unoccupied3. Area compares its Space Temperature with its Unoccupied Cooling

Setpoint.

a. When the Area Space Temperature is above its Unoccupied Cooling Setpoint (typically 85°F (29.4°C)), the Area operating mode transitions to Unoccupied Heating/Cooling.

b. When the Area Space Temperature falls below the Unoccupied Cooling Setpoint minus the unoccupied differential (typically 4°F (2.2°C)), the Area operating mode transitions back to Unoccupied, so it shuts off at 81°F (27.2°C)).

4. When the Area operating mode transitions to Unoccupied Heating/Cooling, it controls the operating mode of all cooling only and heating/cooling VAV members to Unoccupied Heating/Cooling at the Area priority level.




Troubleshooting

VAV object 6. The operating mode controls the following values to the VAV boxes at the Area priority level:


• Heat Cool Mode Request = Morning Warm-up, PreCool, or Max Heat (the Heat Cool mode request is determined by comparing the space temperature of each of the Area equipment members to the Space Temperature Setpoint BAS value sent to the unit by the Tracer SC. If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.)





8. The VAV box damper modulates to maintain the active space temperature setpoint.

9. The VAV box heating or cooling minimum airflow is based on the heat or cool control action of the VAV box.




10. Reheat and parallel fans are disabled if the VAV box is in PreCool.


• controls the operating mode of the common space VAV members to Unoccupied Heating/Cooling at the VAS priority level.

• controls the operating mode of the VAV air handler members to Unoccupied Heating/Cooling at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).

• AHU Heat Cool Mode Request = Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint on the Configuration page of the VAS. If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up.



Tracer SC

(Software)

Unit Controller




Troubleshooting

AHU object 13. The operating mode controls the following values to the AHU at the VAS priority level:











• Economizer Enable = Release15. The AHU begins producing cool air(b).

(a)The length of this delay is adjustable. This is located on the Systems > VAS > Configuration page. Set the time in the Air Handler Startup Delay field.(b)There may be a time delay here depending on the AHU type.


Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied Heating/Cooling—Heating Mode with Central Heat

Typical scenarios:

• Installations with an AHU equipped with gas heat/electric heat, and with perimeter heat in the space (such as electric baseboard heaters), but with no heat in the VAV boxes.

• Installations where the AHU is equipped with hot water or a steam coil, and VAV boxes with electric heat.

Assumptions

This sequence of operation assumes the following settings are in place:• Area Heat/Cool mode status = Heating• Area is part of an HVAC schedule.• The check box for “Allow VAVs to use auxiliary heat at night” is NOT selected on the Tracer SC

VAS configuration page.


The following steps occur in the order shown during Unoccupied Heating/Cooling mode in a scenario where the system is heating with central heat and not using local heat.


Tracer SC

(Software)

Unit Controller



Area 2. The Area operating mode is Unoccupied3. Area compares its Space Temperature with its Unoccupied Heating

Setpoint.

a. When the Area Space Temperature is below its Unoccupied Heating Setpoint (typically 60°F (15.6°C)), the Area operating mode transitions to Unoccupied Heating/Cooling.

b. When the Area Space Temperature rises above the Unoccupied Heating Setpoint plus the unoccupied differential (typically 4°F (2.2°C)), the Area operating mode transitions back to Unoccupied, so it shuts off at 64°F (17.8°C)).

4. When the Area operating mode transitions to Unoccupied Heating/Cooling, it controls the operating mode of all heating only and heating/cooling VAV members to Unoccupied Heating/Cooling at the Area priority level.




Troubleshooting




– Morning Warm-up or PreCool is determined by comparing the space temperature of each of the Area equipment members to the Space Temperature Setpoint BAS of each member sent to the unit by the Tracer SC. If the space temperature is above the setpoint, the Tracer SC sends PreCool. If the space temperature is below the setpoint, the Tracer SC sends Morning Warm-up.


7. The VAS controls the Auxiliary Heat Control point to Disabled (value of 0) at the VAS priority (refer to Step 12).







• Cooling control action: If the source temperature is below the auto changeover setpoint minus 10°F (5.6°C).


• Reheat and parallel fans are disabled if the VAV box is in Precool. 11. The VAV box also receives the following value from the VAS.

• Auxiliary Heating Enabled = Disable (refer to assumption 3 on p. 219).


Tracer SC

(Software)

Unit Controller




Troubleshooting


• controls the operating mode of the common space VAV members to Unoccupied Heating/Cooling at the VAS priority level.

• controls the operating mode of the VAV air handler members to Unoccupied Heating/Cooling at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).

• AHU Heat Cool Mode Request = Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint (located on the Configuration page of the VAS). If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up).

13. The VAS also controls the auxiliary heat at all the VAV boxes, including the common space VAV boxes, by sending the following value to the VAV object:

• Auxiliary Heating Enabled = Disable (refer to assumption 3 on p. 219).14. Ventilation functions are disabled.

AHU object 15. The AHU object sends the following to the VAV AHU:


• Heat Cool Mode Request = Morning Warm-up or PreCool (If the VAS Average Space Temperature is above the VAV AHU Startup Temperature, the value is PreCool. If the VAS Average Space Temperature is below or equal to the VAV AHU Startup Temperature, the value is Morning Warm-up)(based on Step 12).





Tracer SC

(Software)

Unit Controller




Troubleshooting



• Heat Cool Mode Request = Morning Warm-up or PreCool (If the VAS Average Space Temperature is above the VAV AHU Startup Temperature, the value is PreCool. If the VAS Average Space Temperature is below or equal to the VAV AHU Startup Temperature, the value is Morning Warm-up)(based on Step 12).



• Economizer Enable = Release17. The AHU begins supplying hot or neutral air(b) based on the active space

temperature it receives from Tracer SC(c) and the VAS Startup Setpoint.

• Active space temperature is below the VAS Startup Setpoint then the air handler supplies Hot air (if the air handler is running in the constant volume mode, it will report Max Heat to the VAS. The VAS then controls the Heat/Cool Mode Request of all the VAV members to Max Heat at the VAS control priority level.)

• Active space temperature is above the VAS Startup Setpoint then the air handler supplies Cold or Neutral air

(a)The length of this delay is adjustable. This is located on the Systems > VAS > Configuration page. Set the time in the Air Handler Startup Delay field.(b)There may be a time delay here depending on the AHU type.(c)There are several choices available for this value. The first choice is probably the VAS average space temperature with the second choice being the VAS minimum

space temperature.


Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied Heating/Cooling—Heating Mode with Local Heat and a Central Fan

Typical scenarios:

Installations with an AHU equipped with a central fan but no heat, and with VAV boxes with reheat (no fans).

Assumptions

This sequence of operation assumes the following settings are in place:• Area Heat/Cool mode status = Heating• Area is part of an HVAC schedule.• The check box for “Allow VAVs to use auxiliary heat at night” is selected on the Tracer SC VAS

configuration page.


The following steps occur in the order shown during Unoccupied Heating/Cooling mode in a heating with local heat and a central fan scenario.


Tracer SC

(Software)

Unit Controller



Area 2. The Area operating mode is Unoccupied3. Area compares its Space Temperature with its Unoccupied Heating

Setpoint.

a. When the Area Space Temperature is below its Unoccupied Heating Setpoint (typically 60°F (15.6°C)), the Area operating mode transitions to Unoccupied Heating/Cooling.

b. When the Area Space Temperature rises above the Unoccupied Heating Setpoint plus the unoccupied differential (typically 4°F (2.2°C)), the Area operating mode transitions back to Unoccupied, 64°F (17.8°C).

4. When the Area operating mode transitions to Unoccupied Heating/Cooling, it controls the operating mode of all heating only and heating/cooling VAV members to Unoccupied Heating/Cooling at the Area priority level.




Troubleshooting




– Morning Warm-up or PreCool is determined by comparing the space temperature of each of the Area equipment members to the Space Temperature Setpoint BAS sent to the unit by the Tracer SC. If the space temperature is above the setpoint, the Tracer SC sends PreCool. If the space temperature is below the setpoint, the Tracer SC sends Morning Warm-up.





8. If in Max Heat mode, the VAV box opens its damper to the Maximum Heat Airflow setpoint.





• Reheat and parallel fans are disabled if the VAV box is in Precool. 10. The VAV box also receives the following value from the VAS (refer to Step

11).

• Auxiliary Heating Enabled = Enable (refer to assumption 3 on p. 223).


Tracer SC

(Software)

Unit Controller




Troubleshooting


• Controls the operating mode of the common space VAV members to Unoccupied Heating/Cooling at the VAS priority level.

• VAS sends the following to all of its VAV members: Auxiliary Heating Enabled = Enable (refer to assumption 3 on p. 223).

• Controls the operating mode of the VAV air handler members to Unoccupied Heating/Cooling at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).

• The VAS also controls the AHU Heat Cool Mode Request to Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint (located on the Configuration page of the VAS). If the space temperature is above the setpoint, the Tracer SC sends PreCool. If the space temperature is below the setpoint, the Tracer SC sends Morning Warm-up.














• Economizer Enable = Release15. The AHU begins supplying air to the space.



Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied Heating/Cooling—Heating Mode with Local Heat and No Central Fan for Night Heat

Typical scenarios: • AHU without heat and the building owner wants to use the reheat in the VAV boxes (and fans)

instead of the AHU central fan for unoccupied heating.• AHU without heat and the building owner wants to use the VAV boxes with fans and perimeter

heat without the use of the AHU central fan.• Do not use this scenario with shutoff VAV boxes with heat.

Assumptions

This sequence of operation assumes the following settings are in place:• The check box for “Allow VAVs to use auxiliary heat at night” is selected on the Tracer SC VAS

configuration page.

• The VAV box unoccupied heating setpoint is above the Area unoccupied heating setpoint.


The following steps occur in the order shown during Unoccupied Heating/Cooling mode when heating with local heat and there is no central fan for night heat.


Tracer SC

(Software)

Unit Controller


Scheduling 1. The HVAC schedule is Unoccupied.

Area 2. The Area operating mode is Unoccupied3. Area compares its Space Temperature with its Unoccupied Heating Setpoint.

Important: Set the Area Unoccupied Heating Setpoint to a very low setting (e.g., 40°F). Because the Unoccupied Heating setpoint is so low, the Area operating mode will not transition to Unoccupied Heating/Cooling.

4. Ventilation and all VAV members are Unoccupied or disabled.






Troubleshooting



• Heat Cool Mode Request = Off.7. The VAV box also receives the following value from the VAS (refer to Step 13 ).

• Auxiliary Heating Enabled = Enabled (refer to assumption 1 on p. 226).8. The VAV box uses its unoccupied setpoints (specifically, its unoccupied heating

setpoint).9. Ventilation functions are disabled.10. Local heat is enabled.11. The VAV box runs its local fan for heating.12. The VAV box enables remote heat (perimeter heat).

VAS 13. VAS detects that the operating mode of its VAV members remains Unoccupied and:

• controls the operating mode of the common space VAV members to Unoccupied at the VAS priority level.

• controls the operating mode of the VAV air handler members to Unoccupied at the VAS priority level.

• AHU Heat Cool Mode Request = Off14. The VAS also controls the auxiliary heat at all the VAV boxes, including the

common space VAV boxes, by sending the following value to the VAV object:

• Auxiliary Heating Enabled = Enable (refer to assumption 1 on p. 226).15. Ventilation functions are disabled.16. The VAV box uses its local heat.



• Heat Cool Mode Request = Off.






• Heat Cool Mode Request = Off.





Tracer SC

(Software)

Unit Controller




Troubleshooting

Night Purge

Typical scenarios: • This scenario works best and is used most in drier climates (e.g., Los Angeles, Phoenix, etc.).

Assumptions

This sequence of operation assumes the following settings are in place:• The VAV objects added as members to the Area are identified as Night Purge members.• Area operating mode is Unoccupied• Area must be in the cooling mode.• Night Purge must be enabled in the Area function page.• The Night Purge economizing decision must be true on the Area function page.• The space temperature must be warmer than the outdoor air temperature by the Outdoor/

space Temperature Differential defined on the Area function page.• The current time must fall within the time frame defined for Night Purge on the Area function

page.


The following steps occur in the order shown during Night Purge mode.


Tracer SC

(Software)

Unit Controller


Scheduling 1. The HVAC schedule is Unoccupied.

Area 2. When the Area operating mode transitions from Unoccupied to Night Purge (based on the conditions described above in Assumptions), it controls the operating mode of all VAV members to Night Purge at the Area priority level.




• Heat Cool Mode Request = Night Purge



• Heat Cool Mode Request = Night Purge6. The VAV box damper opens when the AHU goes into constant volume

mode.7. Reheat and parallel fans are disabled if the VAV box is in PreCool.



Troubleshooting

VAS 8. VAS detects the operating mode of its VAV members are in Night Purge mode and controls the following at the VAS priority level:

a. AHU object operating mode to Night Purge.

b. Common space VAV boxes to Night Purge.






• Economizer Enable = Enabled






• Economizer Enable = Enabled


Tracer SC

(Software)

Unit Controller




Troubleshooting

Unoccupied Humidify

This is not a recommended application for VAV air systems.



Troubleshooting

Unoccupied Dehumidify

Typical scenarios: This scenario works best and is used most in hot and humid climates (e.g., Miami, Houston, etc.).

Assumptions

This sequence of operation assumes the following settings are in place:• The VAV objects added as members to the Area are identified as Dehumidifying members (not

limited to VAV objects, but can also include binary output objects.)• Area operating mode is Unoccupied• Unoccupied Dehumidification must be enabled in the Area function page.• The Area space humidity must be above the Enable Dehumidification setpoint.


The following steps occur in the order shown during Unoccupied Dehumidify mode


Tracer SC

(Software)

Unit Controller



Area 2. The Area operating mode is Unoccupied3. Area compares its space humidity sensor with its Enable Dehumidification

setpoint.

a. When the Area space humidity is above its Enable Dehumidification Setpoint (typically 60%), the Area operating mode transitions to Unoccupied Dehumidify.

b. When the Area space humidity is below its Disable Dehumidification Setpoint (typically 55%), the Area operating mode transitions back to Unoccupied.

4. When the Area operating mode transitions to Unoccupied Dehumidify, it controls the operating mode of all dehumidify VAV members to Unoccupied Dehumidify at the Area priority level.

5. Ventilation and non-dehumidifying members are Unoccupied or disabled.




– Morning Warm-up or PreCool is determined by comparing the space temperature of each of the Area equipment members to the Space Temperature Setpoint BAS sent to the unit by the Tracer SC. If the space temperature is above the setpoint, the Tracer SC sends PreCool. If the space temperature is below the setpoint, the Tracer SC sends Morning Warm-up.




Troubleshooting




8. The VAV box damper modulates to maintain the active space temperature setpoint.

9. The VAV box heating or cooling minimum airflow is based on the heat or cool control action of the VAV box.


• Cooling control action: If the source temperature is below the auto changeover setpoint minus 10°F (5.6°C).


10. Reheat and parallel fans are disabled if the VAV box is in PreCool.


• controls the common space VAV members operating mode to Unoccupied Dehumidify at the VAS priority level.

• controls the operating mode of the VAV air handler members to Unoccupied Dehumidify at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open).




Tracer SC

(Software)

Unit Controller




Troubleshooting

AHU object 13. The operating mode controls the following values to the AHU at the VAS priority level:


• AHU Heat Cool Mode Request = Morning Warm-up or PreCool (the Heat Cool mode request is determined by comparing the VAS average space temperature to the VAV AHU Startup Setpoint. If the space temperature is above the setpoint, the SC sends PreCool. If the space temperature is below the setpoint, the SC sends Morning Warm-up (based on Step 11).












Tracer SC

(Software)

Unit Controller




Troubleshooting

Timed Override

Assumptions

This sequence of operation assumes the following settings are in place:• The VAV boxes, with Timed Override capability, added as members of the Area and the override

check box is selected. This can be done using the Area creation wizard, or from the Member Configuration screen (shown below).

• Timed override is enabled on the Area Configuration page (Operations section) and its duration is defined.


The following steps occur in the order shown during Timed Override mode.


Tracer SC

(Software)

Unit Controller


Scheduling 1. The HVAC schedule controls the Area to Unoccupied.

VAV Box 2. The On button on the zone sensor is pushed and held (for 5 seconds) by the tenant to initiate a timed override for the space.



Troubleshooting

Area 3. The Area monitors all of the members, designated as override, for a Timed Override request from a zone sensor. When an override is detected the following happens:

• The Area operating mode changes to Occupied

• The Area Occupancy Request is overridden to Bypass (at the Area priority level)

• Area controls the operating mode of all of its members to Occupied



• Heat Cool Mode Request = Release (at the Area priority level)



• Heat Cool Mode Request = Release (at the Area priority level)

Note: The VAV box Heat/Cool mode is determined by the priority array, where the highest level mode (lowest number) is applied when control is released.


• controls the operating mode of the common space VAV members to Occupied at the VAS priority level

• controls the operating mode of the VAV air handler members to Occupied at the VAS priority level (there is a time delay(a) in VAS to allow time for the common space VAV boxes to open)


AHU object 7. The AHU receives the following values from the VAV AHU object (at the VAS priority level):






AHU 8. The AHU receives the following values from the AHU object (at the VAS priority level):

• Occupancy Request = Occupied • Heat Cool Mode Request = Release• Minimum OA Damper Position = Release• Outdoor Air Flow Setpoint = Release• Economizer Enable = Release



Tracer SC

(Software)

Unit Controller




Troubleshooting

Communications Loss

Typical scenarios: • The SC is powered down for service (code update) and loses communications to the AHU,

VAVs, and Unit Controllers.

Assumptions

This sequence of operation assumes the following:• The send/receive heartbeat settings are not altered.• There is no space temperature sensor on the AHU• There are discharge air sensors on the VAV boxes.


The following steps occur in the order shown during Communication Loss mode.


Tracer SC

(Software)

Unit Controller


All Controllers 1. Each unit controller uses its last communicated value from the Tracer SC for 15 minutes (the receive heartbeat timer setting).

After 15 minutes

VAV Box 2. VAV boxes with LonTalk controllers revert to their local inputs and setpoints.

3. For VAV boxes with BACnet controllers, their occupancy reverts to Occupied and all communicated sensor values enter a fault state and the controller reverts to local sensor values. All setpoints within the controller remain in their last communicated state.

Note: If there is no hardwired zone sensor or no locally bound zone sensor available, the VAV box generates a space temperature fail diagnostic and puts the air valve at the cooling minimum airflow setting. All heat will be off. A series fan will be on. A parallel fan will be off.

AHU 4. AHUs with LonTalk controllers revert to their local inputs and setpoints. 5. For AHUs with BACnet controllers, their occupancy reverts to Occupied

and all communicated sensor values enter a fault state and the controller reverts to local sensor values. All setpoints within the controller remain in their last communicated state.



Troubleshooting

Isolating Problem VAV Boxes

One bad apple can sometimes spoil the whole bunch. This analogy is applicable to VAS too. Fortunately, VAS has an advanced feature that allows for manually preventing a problem VAV box from contributing to the collective. Select the Members tab in the Tracer SC VAS editor (refer to Figure 148). To remove the problem VAV box from the VAS, perform the following steps:

1. From the Tracer SC select Systems in the left-hand navigation and then select the appropriate VAS from the Variable Air Systems list.

2. Click Members.3. Select the check box for any VAV box in the member list. 4. Click actions... > edit configuration. All the VAV boxes will display in the configuration

window.5. Locate the VAV box in the VAV Members list and uncheck the check box beneath the category

where the VAV box is not functioning properly (calculations, duct opt, vent opt, and common space).

6. Click Save.7. Fix the VAV box. 8. When the VAV box is fixed, return to the VAS member configuration page and re-enable what

was just disabled.

Figure 148. Getting Rid of problem VAV boxes

Possible Duct Pressure Optimization Problems

For duct pressure optimization, the VAV box with the “most-open” air valve determines which way the requested duct pressure setpoint moves. If one VAV box is always starved for air (the bad apple), its air damper will typically be open to 100% at all times. Duct pressure optimization will increase its requested duct static pressure setpoint until it bumps up against the duct static pressure setpoint high limit. This is not a desirable behavior.

VAS will report which VAV box has the most-open air valve, but VAS does not know if this VAV box has a problem. The technician must determine that by more intuitive means. VAS can only keep track of one most-open VAV box at a time even if there are two VAV boxes with valves open to the same percentage. There will always be a most-open air damper in the VAS so removing the problem VAV box will only make another one show up (although this time it may not be a bad one).



Troubleshooting

Possible Ventilation Optimization Problems

For the ventilation optimization feature in VAS, the VAV box with the highest ventilation ratio determines which way the requested outdoor airflow setpoint moves. Using the same example as discussed previously (a VAV box that is always starved for air), the VAV box ventilation ratio is likely to be 1.0 (or whatever value the VAS point “Ventilation Optimization Maximum Percentage of Outdoor Air” is restricting the ventilation ratio to be). Consequently, ventilation optimization is going to over-ventilate the building. The indoor air quality will benefit from excessive ventilation, but the costs associated with conditioning that outdoor air will rise dramatically. (The AHU is going to have to work harder to heat or cool the extra outdoor air to 55 degrees).

Just as with duct pressure optimization, VAS reports which VAV box has the highest ventilation ratio, but it does not know if this VAV box has a problem; it keeps track of one highest ventilation ratio at a time; and as problem VAV boxes are removed, VAS continues to report the next VAV box with the highest ventilation ratio, which may or may not have a problem.

Possible Space Temperature Summary Problems

For the space temperature summary feature in VAS, each VAV space temperature contributes its value to the minimum, average, and maximum temperature calculations. One substantially high or low value is not likely to alter the average space temperature in the VAS (had it not been substantially high or low) but it is going to prevent finding out where the next warmest or coldest zone in your building is.

Again, VAS reports which box has the warmest and coldest space temperature, but it does not give a reason; it is up to the technician to determine why by some other means. There will always be a maximum and minimum space temperature in the VAS so simply getting rid of one or the other will only make another show up in its place.



Appendix A: Controller Flow Settings Worksheet

Use the worksheet shown in Table 18, p. 240 to record the settings the installing technician should use to configure the controller.

Best Practices for Determining the VV550/551 and UC400 Flow Settings

The numbers below correlate to the numbers shown in Figure 149. They provide general guidelines for determining the values to use on the worksheet. The VV550/551 name is first and the UC400 name is second.

1. Nominal Flow/Air Flow Nominal Status: This value is based on the size of the box. If using Trane VAV boxes, select VariTrane™ F in Rover and the recommended nominal flow for the size of the box should show up. For non-Trane boxes, measure the size of the box and select a VariTrane F box of similar size to get the nominal flow value.

2. Minimum Airflow/Air Flow Setpoint Minimum: This value can be set to zero, or to greater than 10% of the value used for nominal flow. It should be available from the job specs created by the Consulting Engineer.

3. Maximum Airflow/Air Flow Setpoint Maximum: This value should be available from the job specs created by the Consulting Engineer.

4. Standby Minimum Airflow/Air Flow Setpoint Minimum Standby: If this value is not specified on the job specs, use the same value as the minimum airflow.

5. Heating Standby Minimum Airflow/Air Flow Setpoint Maximum Standby Heat: If this value is not specified on the job specs, use the same value as the minimum airflow.

6. Heating Minimum Airflow/Air Flow Setpoint Minimum Heat: If this value is not specified on the job specs, use the same value as the minimum airflow.

7. Heating Maximum Airflow/Air Flow Setpoint Maximum Heat: If this value is not specified on the job specs, use the same value as the maximum airflow.

8. Local Heat Minimum Airflow/Air Flow Setpoint Minimum Local Heat: This value is usually larger than the minimum airflow setting and is dependent on the reheat configuration of the VAV box. Refer to the documentation supplied with the box to determine the minimum airflow for the reheat option installed.

Figure 149.Determining flow settings



9. Occupied Ventilation Setpoint/Ventilation Setpoint Active: This is a calculated value based on the ASHRAE standard. Refer to “Ventilation Optimization,” p. 159 for more information on how this value is calculated. If Ventilation Optimization is not used, set this value to zero.

10. Occupied Standby Ventilation Setpoint/Ventilation Standby Setpoint: This is a calculated value based on the ASHRAE standard. Refer to “Ventilation Optimization,” p. 159 for more information on how this value is calculated. If Ventilation Optimization is not used, set this value to zero.

*From Specs **If using Rover, these values are available in the Ventilation Setup group on the Setup tab.

Table 18. Controller flow settings worksheet (bold indicates UC400 values)

Location Label (e.g., VAV 01-01)

Nom

inal

Flo

w

Air

Flo

w N

om

inal

Sta

tus

Min

imum

Airflow

*

Air

Flo

w S

etp

oin

t M

inim

um

Max

imum

Air

flow

*

Air

Flo

w S

etp

oin

t M

axim

um

Sta

ndby

Min

imum

Air

flow

Air

Flo

w S

etp

oin

t M

inim

um

Sta

nd

by

Hea

ting S

tandby

Min

imum

Air

flow

Air

Flo

w S

etp

oin

t M

axim

um

Sta

nd

by

Hea

t

Hea

ting M

inim

um

Airflow

Air

Flo

w S

etp

oin

t M

inim

um

Hea

t

Heat

ing M

axim

um

Air

flow

Air

Flo

w S

etp

oin

t M

axim

um

Hea

t

Loca

l H

eat

Min

imum

Airflow

Air

Flo

w S

etp

oin

t M

inim

um

Lo

cal

Hea

t

Occ

upie

d V

entila

tion S

etpoin

t**

Ven

tila

tion

Set

po

int

Act

ive

Occ

upie

d S

tandby

Ventila

tion S

etp

oin

t**

Ven

tila

tion

Sta

ndby

Setp

oin

t



Appendix B: Tracer SC Mapping to MP580/581 Network Variable Inputs (nvi) and Profile

Appendix B: Tracer SC Mapping to MP580/581 Network

Variable Inputs (nvi) and Profile

Associations

This mapping occurs automatically when the MP580/581 is installed in the Tracer SC.

Tracer SC MP580/581

SC Name SC Point Type

SC Equipment Type LonTalk Network Variable Name

Profile NV Index

Occupancy Request Multistate Output

Constant Volume Air Handler nviOccSchedule SCC 304

Heat/Cool Request Multistate Output

Constant Volume Air Handler nviApplicMode SCC 307

Emergency Override Multistate Output

Constant Volume Air Handler nviEmergOverride SCC 310


Variable Volume Air Handler nviOccSchedule DAC 315

Heat/Cool Request Multistate Output

Variable Volume Air Handler nviApplicMode DAC 317

Emergency Override Multistate Output

Variable Volume Air Handler nviEmergOverride DAC 318


Programmable Controller nviOccSchedule MP580 330



Appendix C: Member Occupancy Response to Area and

VAS Operating Modes

Area

Table 19 details the occupancy request only of Area members for a given operating mode, Area Heating/Cooling mode, and member type. The operating mode of the Area equipment members will typically follow the Area operating mode.

Table 19. Area member occupancy in response to Area operating modes.

Area Operating Mode

AreaH/C Mode

Area Binary Member Type Area Equipment Member Type

Cool Only Heat Only Heat/Cool Ventilation Cool Only Heat Only Heat/Cool Ventilation

OccupiedHeat Off On(a) On(a) On Occupied Occupied Occupied Occupied

Cool On(a) Off On(a) On Occupied Occupied Occupied Occupied

UnoccupiedHeat Off Off Off Off Unoccupied Unoccupied Unoccupied Unoccupied

Cool Off Off Off Off Unoccupied Unoccupied Unoccupied Unoccupied


Heat Off On On Off Unoccupied Occupied Occupied Unoccupied

Cool On Off On Off Occupied Unoccupied Occupied Unoccupied

Night Purge On(b) Off On(b) Off Occupied(b) Unoccupied Occupied(b) Unoccupied

Optimal StartHeat Off On(a) On(a) Off Unoccupied Occupied(c) Occupied(c) Unoccupied

Cool On(a) Off On(a) Off Occupied(c) Unoccupied Occupied(c) Unoccupied

Optimal StopHeat On On On On Standby(d) Standby(d) Standby(d) Occupied

Cool On On On On Standby(d) Standby(d) Standby(d) Occupied

Unoccupied HumidifyHeat On(e) On(e) On(e) Off Occupied(e) Occupied(e) Occupied(e) Unoccupied

Cool On(e) On(e) On(e) Off Occupied(e) Occupied(e) Occupied(f) Unoccupied

Unoccupied DehumidifyHeat Off Off On(f) Off Occupied(f) Unoccupied Occupied(f) Unoccupied

Cool On(f) On(f) On(f) Off Occupied(f) Occupied(f) Occupied(f) Unoccupied

Humidity Pull DownHeat On(f) On(f) On(f) Off Occupied(f) Occupied(f) Occupied(f) Unoccupied

Cool On(f) On(f) On(f) Off Occupied(f) Occupied(f) Occupied(f) Unoccupied

(a) On if occupied temperature control is disabled; otherwise, it follows the occupied temperature control logic.(b) On/Occupied if Night Purge is enabled; otherwise, it is off.(c) The unit controller occupancy is Occupied, but the outdoor air damper is closed.(d) The unit controller shall be placed in standby mode. BACnet controllers shall have the occupied setpoints set to the Area standby setpoint. LonTalk

controllers will use the standby setpoints to widen the heating and cooling setpoints. Equipment will maintain outdoor air requirements.(e) On or Occupied if the member is a humidify member of Area; otherwise, the member will be Off or Unoccupied.(f) On or Occupied if the member is a dehumidify member or Area; otherwise, the member will be Off or Unoccupied.



Appendix C: Member Occupancy Response to Area and VAS Operating Modes

VAS

Table 20 details the occupancy request only of VAS members for a given operating mode. The operating mode of the air handler and common space VAV boxes will always follow the operating mode of the VAS.

Table 20. VAS member occupancy in response to VAS operating modes.

VAS Operating Mode

VAS Equipment MembersVAS Binary Members

Air HandlerCommon Space

VAV Boxes Ventilation Ventilation

Occupied Occupied Occupied Occupied On

Unoccupied Unoccupied Unoccupied Unoccupied Off


Occupied Occupied Unoccupied Off

Night Purge Occupied Occupied Unoccupied Off

Optimal Start Occupied Occupied Unoccupied Off

Optimal Stop Occupied(a)

(a) VAV air handlers do not support the Standby mode for Occupancy.

Standby Occupied On

Unoccupied Humidify Occupied Occupied Unoccupied Off

Unoccupied Dehumidify Occupied Occupied Unoccupied Off

Humidity Pull Down Occupied Occupied Unoccupied Off



Appendix D: Area and VAS Rank Arbitration for

Operating Mode

Table 21 describes how Area and VAS determines which operating mode it should be in.

Area uses this table to determine the operating mode when several Area functions are active simultaneously

Example: When the Area is Unoccupied, the Unoccupied Heating/Cooling function is active, and Unoccupied Dehumidify function is also active. The resultant operating mode is Unoccupied Heating/Cooling because it has a higher ranking in the table than Unoccuppied Dehumidify). This operating mode is then sent to the Area member VAV boxes.

VAS uses this table to determine operating mode when it is supporting more than one Area. VAS monitors the operating mode sent its member VAV boxes, the VAS responds to VAV boxes operating modes using the ranking listed in Table 21 to determine the VAS operating mode.

Example: Area 1 has an operating mode of Unoccupied Heating/Cooling, while Area 2 has an operating mode of Optimal Start. The VAV boxes in both Areas are also members of the VAS. VAS sees both operating modes and uses Table 21 to arbitrate. VAS determines its operating mode should be Optimal Start because Optimal Start is ranked higher than Unoccupied Heating/Cooling. The VAS operating mode is then passed to the air handler and common space VAV boxes.

Table 21. Area and VAS arbitration rank for operating modes.

Rank Operating Mode How Area Determines Operating Mode

1 Occupied All equipment will be occupied if the conditions for optimal stop are not true.

2 Optimal Stop

The Area can only enter the Optimal Stop mode under the following conditions:• The Area is Occupied• The optimal window is active• The Area determines there is sufficient capacity in the building to maintain

the space temperature within two degrees of the Occupied setpoints.

3 Optimal StartThe area can only enter optimal start if the area is unoccupied, the optimal window is active and the optimal start early limit has been reached.

4 Humidity Pull DownThe area can only enter humidity pull down if the area is unoccupied, the optimal window is active and the humidity pull down early limit has been reached. (only members checked as dehumidification members will respond)

5 Unoccupied Heating/CoolingThe area can only enter night heat cool if the are is unoccupied, night heat cool is enabled and the space temperature is above the unoccupied cooling setpoint or below the unoccupied heating setpoint.

6 Unoccupied DehumidifyNight Dehumidify can occur if the dehumidify function is enabled, the area space humidify rises above the unoccupied humidity setpoint. (only members checked as dehumidification members will respond)

7 Unoccupied HumidifyNight Humidity can occur if the humidify function is enabled, the area space humidity falls below the unoccupied humidity setpoint. (only members checked as humidification members will respond)

8 Night Purge

Night Purge can occur if:• The Area must be unoccupied• The Night Purge function must be enabled.• The Night Purge/Economizing decision must be true.• The space/outdoor air temperature differential must be satisfied. • The space temperature must be at least one degree above the occupied

cooling setpoint. • Only members checked as night purge members will respond.

9 Unoccupied All equipment will be unoccupied if none of the modes defined above are true.



Appendix E: Equipment Response to Operating Modes

Appendix E: Equipment Response to Operating Modes

Table 22 shows how equipment is controlled by Area and VAS for a given operating mode. Each application will control the five points at the assigned priority levels for that application (refer to Table 23, p. 246)

Table 22. Equipment response to operating modes

Property

Operating Mode

All Equipment except VAV AHUs VAV AHU

Occupancy Request

Heat Cool Mode

Request

Min OA Damper

Stpt

OA cfm Stpt

Economizer Enable

Occupancy Request

Heat Cool Mode

Request

Min OA Damper

Stpt

OA cfm Stpt

Economizer Enable

Occupied Occupied Release Release Release Release Occupied Release Release Release Release

Unoccupied Unoccupied Release 0 0 Disable Unoccupied Off(a) 0 0 Disable

Unoccupied Heat/Cool OccupiedMorning

Warm-up(b)

Precool(b)0 0 Release Occupied

Morning Warm-up(c)

Precool(c)0 0 Release

Night Purge Occupied Night purge Release Release Active Occupied Night Purge Release Release Active

Optimal Start OccupiedMorning

Warm-up(b)


Morning Warm-up(c)


Optimal Stop Standby Release Release Release Release Occupied(d) Release Release Release Release

Unoccupied Humidify OccupiedMorning

Warm-up(b)


Morning Warm-up(c)


Unoccupied Dehumidify OccupiedMorning

Warm-up(b)


Morning Warm-up(c)


Humidity Pull down OccupiedMorning

Warm-up(b)


Morning Warm-up(c)


(a) Heat Cool Mode Request is controlled to Off on VAV air handlers to prevent Unoccupied Heating/Cooling operations.(b)Heat Cool Mode Request calculations are calculated using properties from the equipment:

• Heating Cooling Mode Request is Morning Warm-up if the Space Temperature Active is below the Space Temperature Setpoint BAS or if either value is invalid.

• Heating Cooling Mode Request is PreCool if the Space Temperature Active is above or equal to the Space Temperature Setpoint BAS

(c)Heat Cool Mode Request Calculations are calculated by the VAS based on the following:

• Heating Cooling Mode Request is Morning Warm-up if the VAS Average Space Temperature is below the VAV AHU Startup Setpoint or if either value is invalid.

• Heating Cooling Mode Request is PreCool if the VAS Average Space Temperature is above or equal to the VAV AHU Startup Setpoint(d) Occupancy Request is controlled to Occupied as VAV air handlers do not support the Standby mode.



Appendix F: Tracer SC Priority Levels and Assigned

Applications

Table 23 shows the Tracer SC default priority levels along with the applications assigned to those priority levels. Applications will perform all control at the application’s assigned priority level. The priority level names are editable (with the exception of Life Safety - Manual, Life Safety - Auto, Critical Equipment, Minimum On/Off, and Manual Override High).

Table 23. Tracer SC default priority levels and assigned applications

Control Class Priority Level Name Assigned Applications

1 Life Safety-Manual Emergency Override for Users

2 Life Safety-Auto Emergency Override for System Applications

3 Miscellaneous ---

4 Miscellaneous ---

5 Critical Equipment Factory Safety TGP2

6 Minimum On/Off Minimum On/Off

7 Miscellaneous ---

8 Manual Override High User High

9 Programming High TGP2 High

10 Application High VAS

11 Manual Override Medium User Medium

12 Application Medium Area (TOV)

13 Manual Override Low User Low

14 Programming Low Programming Low

15 Application Low Scheduling

16 Miscellaneous ---



Appendix G: Trane Equipment Response to Optimal Start Heating

Appendix G: Trane Equipment Response to Optimal

Start Heating

Table 24 describes how Trane VAV air handlers respond to an Optimal Start heating request based on the unit type.

Note: Some units enter a constant volume mode when placed in an Optimal Start heating mode.

Note: Not all IntelliPak I air handlers report Max Heat during Optimal Start heating mode. To ensure that the VAV box air valves are driven to max cfm setpoint, an additional TGP2 program is necessary. Refer to Figure 150, p. 248.

Table 24. Trane equipment response to Optimal Start Heating.

Equipment/Controller type Equipment Response

IntelliPak (LCI-I) determines whether it should do Morning Warm-up

RTU

Staged heat• Constant volume heat• Reports Max Heat• No ventilation

Modulating heat• Constant volume heat• Reports Max Heat• No ventilation

CSC Any heat• VAV heat• Reports Morning Warm-up• No ventilation

Voyager Commercial (LCI-R)• Constant volume heat• Reports Max Heat• No ventilation

AH540/541 Hydronic heat• VAV heat• Reports Morning Warm-up• No ventilation

AH540/541 Electric heat• VAV heat• Reports Morning Warm-up• No ventilation

MP580/581 Completely programmable – will run as programmed



Figure 150.Excerpt from VAV_Constant_Volume_Drive_max TGP2 program



Appendix H: Common Tracer SC Enumerations


Table 25 lists the common enumerations within Tracer SC. These enumerations are used for both equipment and applications. False and True values are used for binary points, and numeric values show the text and corresponding value used in multi-state point definitions.

Table 25. Tracer SC Enumerations

Key/Point names Enumerations

Air Flow Min Setpoint Source 1 = None (no minimum enforced)2 = Cooling Minimum3 = Heating Minimum4 = Local Heating Minimum5 = Standby Cooling Minimum6 = Standby Heating Minimum7 = Derived from Ventilation Requirements8 = Pressure Dependent Mode Min

Air Flow Override 1 = Air Valves Auto Control2 = Not Used3 = Not Used4 = Not Used5 = Air Valves Full Open6 = Air Valves Full Closed7 = Air Valves Minimum Setpoint8 = Air Valves Maximum Setpoint

Air Valve Position Control Status false (0) = pressure independent controltrue (1) = position control/pressure dependent

Auto Commission Start Request false (0)= Canceltrue (1) = Start

Auto Comm State 1 = Waiting2 = Calibrating3 = Flow Test4 = Fan Test5 = Reheat Test6 = Finished7 = Canceled

Base Loading Active false (0)= Inactivetrue (1) = Active

Baseboard Heat Status 1 = Off2 = On3 = Not Present

Binary Input Status XNote: X = 01 through 04

false (0)= Offtrue (1) = On

Binary Output Override XNote: X = 01 through 04


Binary Output Request XNote: X = 01 through 04


Binary Output Status XNote: X = 01 through 04


Communication Status 1 = Not Communicating2 = No Logical Device Connected3 = Communicating4 = Startup



Condensate Overflow Alarm false (0)= Normaltrue (1) = In Alarm

Condenser Type 1 = None2 = Air Cooled Condenser3 = Water Cooled Condenser4 = Evaporative Condenser

Condenser Water Flow BAS 1 = Flow2 = No Flow3 = Auto

Condenser Water Flow Status false (0)= No Flowtrue (1) = Flow

Condenser Water Pump Request false (0)= Offtrue (1) = On

Condenser Water Pump Status false (0)= Offtrue (1) = On

Cooling Fan Default Cycling false (0)= Cyclingtrue (1) = Continuous

Cooling Fan Default Status 1 = No Default2 = Off3 = Low4 = Undefined5 = Medium6 = Not Used7 = Not Used8 = Not Used9 = High10 = Not Used11 = Not Used12 = Not Used13 = Not Used14 = Not Used15 = Not Used16 = Not Used17 = Auto

Cool Stage X StatusNote: X = 1–8

1 = Off2 = On3 = Not Present

Defrost Status 1 = Off2 = On3 = Not Present

Dehumidification Control Status 1 = Off2 = On3 = Not Present

Dehumid System Enable BAS false (0)= Disabletrue (1) = Auto

Dirty Filter Alarm false (0)= Normaltrue (1) = In Alarm

ECM Fan Output Status false (0)= Offtrue (1) = On

Table 25. Tracer SC Enumerations (continued)





Economizer Enable Type 1 = Absolute Temperature2 = Relative Temperature3 = Absolute Enthalpy4 = Comparative Enthalpy

Economizer Enable BAS 1 = Disabled2 = Enabled3 = Auto

Economizer Enable Water BAS 1 = Disabled2 = Enabled3 = Auto

Economizer Status 1 = At or Below Minimum Position2 = Above Minimum Position3 = Not Present

Economizer System Status 1 = Disabled2 = Enabled3 = Not Present

Economizer Type 1 = None2 = 2 Position Ventilation3 = Modulation Economizer4 = 2 Position Ventilation/Waterside Economizer5 = Waterside Economizer6 = Airside/Waterside Economizer7 = TRAQ Damper8 = Airside Economizer and TRAQ Damper/Sensor9 = Waterside Economizer and TRAQ Damper/Sensor10 = Airside/Waterside Economizer and TRAQ Damper/Sensor

Emergency Override BAS 1 = Normal2 = Pressurize3 = Depressurize4 = Purge5 = Shutdown6 = Fire

EngyWheelPreheatStatus 1 = Inactive2 = Active

Engy Wheel Frost Avoid Status false (0)= Offtrue (1) = On

Engy Wheel Status 1 = Inactive2 = Active

Enthalpy Mode

1 = Disabled 2 = Differential 3 = Fixed 4 = Differential Dry Bulb 5 = Fixed Dry Bulb

Evaporator Water Flow Status false (0)= No Flowtrue (1) = Flow

Evaporator Water Pump Request false (0)= Offtrue (1) = On

Exhaust Fan Failure false (0)= Normaltrue (1) = In Alarm

Exhaust Fan Failure Reset false (0)= Normaltrue (1) = Reset





Exhaust Fan On Off Control 1 = Off2 = On3 = Not Present

Fan Output Status false (0)= Offtrue (1) = On

Fan Speed Cooling 1 = Off2 = Low3 = Medium4 = High5 = Auto

Fan Speed Heating 1 = Off2 = Low3 = Medium4 = High5 = Auto

FinalFilterStatus 1 = Clean2 = Dirty3 = Not Present

Filter Timer Reset Request false (0)= Normaltrue (1) = Reset

Generic BI1 Status 1 = Off2 = On3 = Not Present

Generic Binary Input Status false (0)= Offtrue (1) = On

Generic BO1 Request false (0)= Offtrue (1) = On

Generic BO1 Status 1 = Off2 = On3 = Not Present

Generic Loop Enable BAS false (0)= Offtrue (1) = On

Generic Relay Status false (0)= Offtrue (1) = On

Generic Stage 1 Status false (0)= Offtrue (1) = On

Generic Stage 2 Status false (0)= Offtrue (1) = On






Heat Cool Mode Request 1 = Auto2 = Heat3 = Morning Warm-up4 = Cool5 = Night Purge6 = Pre Cool7 = Off8 = Test9 = Emergency Heat10 = Fan Only11 = Free Cool12 = Ice-Making13 = Max Heat14 = Economy Mode15 = Dehumidifying16 = Calibrate

Heat Cool Mode Status 1 = Auto2 = Heat3 = Morning Warm-up4 = Cool5 = Night Purge6 = Pre Cool7 = Off8 = Test9 = Emergency Heat10 = Fan Only11 = Free Cool12 = Ice-Making13 = Max Heat14 = Economy Mode15 = Dehumidifying16 = Calibrate

Heat Output x StatusNote: X = 1–3


Heat Stage X StatusNote: X = 1–8

1 = Off2 = On3 = Not Present

Heating Fan Default Cycling false (0)= Cyclingtrue (1) = Continuous

Heating Fan Default Status 1 = No Default2 = Off3 = Low4 = Undefined5 = Medium6 = Not Used7 = Not Used8 = Not Used9 = High10 = Not Used11 = Not Used12 = Not Used13 = Not Used14 = Not Used15 = Not Used16 = Not Used17 = Auto

High Static Alarm false (0)= Normaltrue (1) = In Alarm





Hot Gas Bypass Active false (0)= Inactivetrue (1) = Active

Humidification Enable BAS false (0)= Disabletrue (1) = Auto

IsoVlvStatus1 1 = Closed2 = Open3 = Not Present

IsoVlvStatus2 1 = Closed2 = Open3 = Not Present

Local Economizer Status 1 = Disabled2 = Enabled3 = Not Present

Local or Remote Control Command false (0) = Stand Alone Controltrue (1) = BAS Control

Low Temperature Alarm false (0) = Normaltrue (1) = In Alarm

Maintenance Ping 1 = Off2 = On3 = Not Present

Number of Fan Speeds 1 = Zero2 = One3 = Two4 = Three5 = Variable Speed

Occupancy Input false (0) = Occupiedtrue (1) = Unoccupied

Occupancy Request 1 = Occupied2 = Unoccupied3 = Occupied Bypass4 = Occupied Standby

Occupancy Status 1 = Occupied2 = Unoccupied3 = Occupied Bypass4 = Occupied Standby

Occupant Call 1 = Off2 = On3 = Not Present

Operating Mode Status 1 = Occupied2 = Unoccupied3 = Optimal Start4 = Humidity Pulldown5 = Optimal Stop6 = Unoccupied Heating/Cooling7 = Night Purge8 = Unoccupied Humidify9 = Unoccupied Dehumidify10 = Unknown Mode

PreFilter Status 1 = Clean2 = Dirty3 = Not Present






Primary Filter Status 1 = Clean2 = Dirty3 = Not Present

Primary Heat Reheat Enable Cmd false (0) = Enabletrue (1) = Disable

Remote Fan Command false (0) = Cyclingtrue (1) = Continuous

Remote Minimum Position Enabled Cmd false (0) = Enabletrue (1) = Disable

Reset Diagnostic Request false (0) = Normaltrue (1) = Reset

Return Fan Failure false (0) = Normaltrue (1) = In Alarm

Return Fan Failure Reset false (0) = Normaltrue (1) = Reset

Return Fan On Off Control 1 = Off2 = On3 = Not Present

Return Fan Proving Status 1 = Off2 = On3 = Not Present

Reversing Valve Status 1 = Heating2 = Cooling3 = Not Present

Space Temp Local Spt Enable false (0) = Disabletrue (1) = Enable

Supply Fan Failure false (0) = Normaltrue (1) = In Alarm

Supply Fan Failure Reset false (0) = Normaltrue (1) = Reset

Supply Fan On Off Control 1 = Off2 = On3 = Not Present

Supply Fan Switch Control Local false (0) = Disabletrue (1) = Enable

Supply Fan Proving Status 1 = Off2 = On3 = Not Present

Timed Override Status 1 = Idle2 = On3 = Cancel

UCM Diagnostic Present false (0) = Normaltrue (1) = In Alarm





Unit Type Trane 1 = 1 Heat/1 Cool2 = Heat Pump3 = Blower Coil4 = Unit Ventilator5 = Fan Coil6 = Rooftop7 = Air Handler8 = Vertical Self Contained9 = Unitary10 = VAV Box11 = Fan Coil

Water Valve Control Request 1 = Off2 = Not Valid3 = Not Valid4 = Not Valid5 = Open6 = Close





Glossary

Purpose

This glossary defines acronyms, abbreviations, and technical terms used in this document.

Abbreviations and acronyms

AHU air-handling unit

AIP analog input point

AOP analog output point

ASHRAE American Society of Heating, Refrigerating, and Air-conditioning Engineers

AWG American wire gauge

BACnet building automation and control network

BAS building automation system

BIP binary input point

BOP binary output point

cfm cubic feet/minute

CPL custom programming language

CPU central processing unit

CSC commercial self-contained unit

DAC Discharge Air Controller profile

DAT discharge-air temperature

DDC direct digital control

EA exhaust air

EAT exhaust-air temperature

HVAC heating, ventilation, and air-conditioning

I/O input/output

IAQ indoor air quality

ICS Integrated Comfort system

IP Internet Protocol

IPAK IntelliPak rooftop unit

LAN local area network

LCI LonTalk communication interface

LED light emitting diode

L/s Liters per second

MA mixed air

MAT mixed-air temperature

MWU morning warm-up

nvi network variable input

nvo network variable output

OA outdoor air

OAT outdoor-air temperature

OSS Optimal Start/Stop



Glossary

PDF Portable Document Format file extension (*.pdf)

PID proportional, integral, derivative

PSI pounds per square inch

RA return air

RAT return-air temperature

RCF Rover configuration file extension (*.rcf)

RTU rooftop unit

SA supply air

SAT supply-air temperature

SCC Space Comfort Controller profile

SNVT standard network variable type

STD standard file format extension (*.std)

TGP Tracer graphical programming

TOD time-of-day scheduling

TOV Timed Override

UI user interface

UTP unshielded twisted pair

Vac volts-alternating current

Vdc volts-direct current

VAS VAV air system

VAV variable-air-volume

VFC ventilation flow control

VFD variable frequency drive

VSD variable speed drive

Technical terms

Acronyms are listed according to the most common way to refer to them. In some cases, the acronyms are the main entry, and in other cases, the full phrase is the main entry.

A

active mode. See Rover operating modes.

AH540/541 air-handler controller. See Tracer AH540/541 air-handler controller.

AIP. See analog input point.

air and water balance. A task usually performed by contractors to measure, calibrate, and modulate the air and water flow through the system. Trane uses the Air and Water Balancing tool, which is part of the Rover suite of software tools.

air valve. Sometimes also referred to as an air damper.

alarm. An audible or visual signal from a building automation system or controller that warns of an abnormal, critical operating condition.

analog. Pertaining to a device or signal that constantly varies in strength or quantity. For example, temperature, humidity, and flow rate have analog values.



Glossary

analog input. A varying voltage, current, or resistive signal that can be converted to units of temperature, pressure, humidity, and so on.

analog input point (AIP). 1. A location on a controller where the wiring for an analog input is terminated.

analog output. A varying voltage or current signal used to change the position of an external device, such as a valve damper, or temperature setpoint.

analog output point (AOP). 1. A location on a controller where the wiring for an analog output is terminated.

AOP. See analog output point.

ASHRAE. American Society of Heating, Refrigerating, and Air-Conditioning Engineers. An international organization that advances the science of heating, ventilation, air-conditioning, and refrigeration (HVAC). It conducts research, writes standards, and promotes continuing education in the HVAC industry.

auto-commissioning. The Tracer VV550/551 controller includes a special operating sequence designed to validate the proper operation of all outputs and the ability to measure all inputs. The purpose of this auto-commissioning sequence is to minimize the labor required to commission the unit in the field.

B

BACnet Protocol. BACnet is a Data Communications Protocol for Building Automation and Control Networks. It is an ASHRAE, ANSI, and ISO standard protocol.

BACnet attempts to encompass the full range of control devices by modeling them as objects, each of which may have an assortment of properties. For example, a temperature sensor may be considered an object of type Analog Input. Such an object will have many properties, such as Present Value, Units, Resolution, and Status.

BAS. Building automation system. A combination of controllers and software products that communicate with and control mechanical systems to manage buildings. The managed systems can include HVAC systems, lighting systems, access control, and other systems. Also called building management system (BMS).

binary. 1. A number system with only two digits, 0 and 1, in which each symbol represents a decimal power of two. 2. Any system that has only two possible states or levels, such as a switch that is either on or off. (On is 1 and off is 0.) 3. Represented in a computer circuit by the presence of voltage (1) or absence of voltage (0).

binary input. A two-position signal indicating on/off status. Examples include flow switches, limit switches, and other contacts.

binary input point (BIP). 1. A location on a controller where the wiring for a binary input is terminated.

binary output. An on/off control from a microprocessor. Examples include controls to fans, pumps, dampers, and other controlled outputs.

binary output point (BOP). 1. A location on a controller where the wiring for a binary output is terminated.

binding. On LonTalk communication links, bindings allow two or more devices to share common information, such as the same setpoint or zone temperature sensor. Bindings link a network variable in one device with a network variable in another device. See also network variable.

BIP. See binary input point.



Glossary

BOP. See binary output point.

building automation system (BAS). See BAS.

C

calibration. The process of standardizing a measuring instrument by determining the deviation from a known value to find the proper correction factor. The Rover service tool can be used to calibrate the space temperature and hard-wired setpoint from a zone sensor.

Climate Changer air handler. Trane’s brand of air handling units. Climate Changer air handlers control the airflow and air temperature for an applied air handling system. Trane’s Modular Climate Changer allows every air handler to be custom tailored to the specific requirements of a job. Modular Climate Changers are currently available in sizes ranging from 3,000 to 100,000 cfm.

comm link. See communications link.

commissioning. The process of starting up and verifying correct operation of a building automation system or device.

common space VAV. Common space VAVs are unique to the Tracer SC VAS. They are VAV boxes that are not assigned to a specific Area and are controlled by the VAS application. They allow the air handler to supply air to individual spaces without having to provide supply air to all spaces. Common space VAVs do this by creating an outlet for excess airflow when the air handler is operating at minimum flow settings, which would still provide too much airflow for the space making the request.

communications link. The connection between devices that allows data transfer. Trane communications links typically use twisted-pair wire.

constant-volume system. An air distribution system that supplies a constant volume of air while varying temperature to maintain comfort.

control loop. The process that manages HVAC equipment. Control loops measure data using sensors, and process the data at a controller to determine a control response, which results in an action at the controlled equipment. See also DDC, PID loop.

controller. A microelectronic device that manages the operation of HVAC equipment. Controllers that manage only one piece of equipment are called unit controllers or unit control modules (UCMs). See also Tracer controllers.

D

DAC profile. Discharge Air Controller profile. A LonMark® functional profile for HVAC controllers that provide variable airflow, such as air handlers and VAV rooftop units. The controlled element is the discharge-air temperature rather than the space temperature. Compare SCC profile.

daisy-chain configuration. A wiring configuration used for LonTalk communications. All devices are wired as shown below. Refer to “Installation,” p. 26 for more information on LonTalk communication wiring.

UC UC UC

SC



Glossary

Daytime Warm-up. Daytime Warm-up occurs during occupied periods. When the air handler’s space temperature is colder than its “Daytime Warm-up Setpoint”, the air handler supplies hot air to the system.

DDC. Direct digital control. A microprocessor-based control methodology that relies on software to perform control logic. DDC is more flexible, easier to integrate with other systems, and more effective than other control methodologies, such as pneumatic control. At Trane, DDC is often used as synonym for PID control. Compare PID control.

DDC/VAV. A variable-air-volume (VAV) system that uses a controller on each VAV box to provide temperature control and to interface with a building automation system.

demand controlled ventilation. A method of maintaining indoor air quality through intelligent ventilation based on occupancy. The quantity of ventilation is controlled based on indoor CO2 levels, which correlate to occupancy levels. Demand controlled ventilation saves money by reducing ventilation during periods of low occupancy.

depressurize. A control request sent to UCMs during smoke control. Used to coordinate supply air and exhaust air to create a negative pressure in a space.

direct digital control (DDC). See DDC.

Discharge Air Controller (DAC) profile. See DAC profile.

E

economizer control. Opening an outdoor-air damper to cool a building with outdoor air, usually when the outdoor air temperature is 40°F to 65°F (5°C to 18°C).

exhaust fan. A fan that removes excess air from a building to prevent over-pressurization and to discharge unwanted air.

F

factory commissioning. The process of connecting and testing controllers in a factory. Controllers are connected to the equipment and operated to verify their operating functionality in detail. This reduces installation costs and helps ensure efficient, quiet, and accurate operation from the first day through the life of the system. Factory mounting provides additional points not available in field installations.

flow tracking. Flow tracking is a special application for controlling pressurization in a space. Flow tracking uses two VAV boxes, one at the supply air inlet and one at the exhaust air outlet, set to different cfm flow settings in order to maintain either a negative or positive airflow in the space.

G

graphical programming. A method of programming based on the assembly of graphically-represented logical blocks. See also TGP.

graphical programming block. See TGP block.

H

heating, ventilation, and air-conditioning (HVAC). See HVAC.

human interface. See user interface.

HVAC. Heating, ventilation, and air-conditioning. Mechanical equipment, such as air handlers and VAV boxes, that provides environmental comfort to building occupants.



Glossary

I

IntelliPak rooftop unit (IPAK). A heating and cooling rooftop unit. The IntelliPak rooftop unit can be configured to meet the requirements of most unitary system jobs and is currently available in 20–130 ton sizes.

Internet Protocol (IP). See IP.

IP. Internet Protocol. The protocol within TCP/IP that governs the transmission of messages. It has been adopted by ASHRAE as a means to communicate BACnet over a network. It allows BACnet to pass through IP devices, such as IP system routers and over the Internet.

IP address. The 32-bit address defined by the Internet Protocol. The IP address is the unique numerical code that is used by each device on a network. It is usually represented in dotted decimal notation (for example, 159.112.138.173). Each of the four values can range from 0 through 255.

L

LCD. Liquid crystal display. A display screen used on some Trane products.

LCI. See Tracer LCI.

Level 4 wire. Used to specify a particular performance of communication wire (normally associated with LonTalk). Trane recommends Level 4 wire for use with LonTalk installations.

liquid crystal display (LCD). See LCD.

LonMark® functional profiles. LonMark® standards that define standard network variable types (SNVTs), standard configuration parameter types (SCPTs), and default and power-up behaviors for compliant HVAC controllers. Many of the latest Tracer controllers use LonMark® profiles, including the Space Comfort Controller (SCC) profile and the Discharge Air Controller (DAC) profile. Compliance with LonMark® profiles is a part of Trane’s commitment to systems integration. See also DAC profile, SCC profile, SCPT, SNVT.

LonMark® Interoperability Association. An association of organizations and individuals who are committed to the development, manufacture, and use of interoperable LonWorks products and networks. Products that conform to LonMark® guidelines can display the LonMark® logo.

LonTalk protocol. An interoperable protocol developed by the Echelon Corporation and named as a standard by the Electronics Industries Alliance (EIA-709.1). It is packaged on a Neuron chip.

low-voltage. Common term for National Electrical Code Article 725 Class 2 wiring. Generally 24 Vac, 100 Vac, or less.

M

mode. See Rover operating modes.

morning warm-up. This functions the same as Daytime Warm-up, except it occurs during a transition from Unoccupied to Occupied or Optimal Start.

N

network variable. An input or output data item from a controller. Network variables enable a controller to exchange data with other devices on the network. Network variables are defined by standard network variable types (SNVTs). See also SNVT.



Glossary

Neuron ID. A unique identifying number assigned to each LonWorks controller. Neuron IDs eliminate the need to set addresses with DIP switches.

Night Purge. Exchanging cool, dry outdoor air with warm inside air in preparation for an Occupied condition.

night setback. Refer to Unoccupied Heating/Cooling.

noise. Electrical interference that creates abnormal characteristics and behaviors on an electrical signal.

O

Optimal Start. The process of efficiently starting HVAC equipment so that the occupied setpoints are achieved at the appropriate time. The equipment uses recirculated air to PreCool or pre-heat a space as quickly as possible before it is Occupied. For example, the Tracer Summit system may be programmed for Occupied temperature at 6:00 AM. With Optimal Start, the system may start at 5:15 AM to reach the setpoint by 6:00 AM.

Optimal Stop. Optimal stop is a scheduled event, but it is also a temperature-based function of Area Control. Optimal stop is the process of efficiently stopping the mechanical heating or cooling in advance of the space going into an Unoccupied mode. Because this is an occupied condition, the air handler and fan continue to run and the outdoor air damper is set to allow minimum outdoor air into the air handler.

output. See analog output, binary output.

P

passive mode. See Rover operating modes.

pressurize. A control request sent to UCMs during smoke control. Used to coordinate supply air and exhaust air to create a positive pressure in a space.

profile. See LonMark® functional profile.

purge. In the HVAC industry, the act of bringing in outdoor air to cool a building. Purging during Unoccupied hours allows the mechanical cooling equipment to operate less during Occupied hours.

R

referencer. In Tracer SC software, allows the value of one property to be set equal to the value of another property.

repeater. An electronic device used to regenerate, at full strength, signals that have weakened. It is used with digital signals and ignores invalid voltages, such as noise.

resistor. An electronic circuit component which offers resistance to the flow of electric current for the purpose of operation, protection, or control. The resistance is measured in ohms.

RJ-11 connector. A connector that attaches computers to LANs. It looks like a telephone connector, but is larger.

rooftop unit (RTU). Roof-mounted packaged cooling and heating unit. Trane offers Voyager, Precedent, and IntelliPak rooftops units in a range of sizes.

room sensor. See zone sensor.



Glossary

Rover operating modes. The Rover LonTalk service tool can operate in one of three modes. In the passive mode, Rover cannot manage networks. This is the safest (and default) mode of operation. In this mode, Rover can configure controllers, but cannot create bindings or perform flash downloads. On third-party networks, only the passive mode should be used. In the server-connected mode, Rover can work on networks where another server, such as a SC or Tracker controller, is on the link. In this mode, Rover can create bindings and perform flash downloads. In the active mode, Rover can configure controllers on a Trane peer-to-peer network (a network without a server). In this mode, Rover can create bindings, perform flash downloads, and clean up communications links.

Rover LonTalk service tool . A software application for monitoring, configuring, and testing Tracer controllers on LonTalk links. Rover is compatible with the EIA/CEA-860 standard for software plug-ins for LonTalk devices. See also EIA/CEA-860 standard, plug-in.

S

SCC profile. Space Comfort Controller profile. A LonMark® functional profile for HVAC terminal devices, such as WSHP, unit vents, blower coils, VAV boxes, and fan coils. SCC controllers control to a space temperature setpoint. Many Tracer controllers use the SCC profile to support systems integration. See also functional profile. Compare DAC profile.

schedules . Times assigned for defined actions to occur for components of the building automation system. These include on/off commands.

sensor. A device used to read or monitor a physical property, such as temperature, pressure, or humidity, for use by a controller or building automation system. See also zone sensor.

server-connected mode. See Rover operating modes.

service pin. A button on a Tracer controller that allows the installer to locate and identify it on the network based on its Neuron ID. When pressed, the service pin sends its Neuron ID to Rover. See also Neuron ID.

setpoint. A desired outcome, such as a room temperature, to be achieved and maintained by an HVAC system. Setpoints can be communicated from a building automation system or set at a zone sensor or touch screen.

smoke control. There are several forms of smoke control ranging from a simple shutdown in response to a fire alarm up to zoned smoke control in a high-rise building. Smoke control is used to keep smoke out of populated areas of a building and ventilate it to the outdoor.

SNVT. Standard network variable type. A definition of data objects in the LonTalk protocol. SNVTs are organized into LonMark® functional profiles for specific applications. The acronym is pronounced snivit.

Space Comfort Controller (SCC) profile. See SCC profile.

standard network variable type (SNVT). See SNVT.

start-up temperature . The start-up temperature is used during a transition from Unoccupied to either Optimal Start or Unoccupied Heating/Cooling. It is used by the AHU when not referencing the heat/cool input property. The AHU compares the space temperature to the start-up temperature defined in the DAC editor. If the space temperature is below the start-up temperature, the system will start heating. If the space temperature is above the start-up temperature, the system will start cooling.

supply fan. A fan that moves air through an HVAC system to provide hot or cold air to an area.



Glossary

T

terminal unit. HVAC equipment that provides comfort directly to a space. For example, fan coils and unit ventilators. Air-handlers are not normally terminal units, but the VAV boxes that provide conditioned air to a space are.

TGP. Tracer graphical programming. A programming language for HVAC applications that are controlled by Tracer MP580/581 programmable controllers. TGP programs consist of logical blocks assembled into a picture that describes the sequence of operation.

TGP2 block. A programming unit, such as OR and ON, used to assemble TGP2 programs. Examples include input and output blocks, constant blocks, function blocks, logic blocks, and variable blocks.

Tracer AH540/541 air-handler controllers. Controllers that support air-handling product configurations with analog modulating valves, economizer dampers, and face and bypass dampers. Tracer AH540/541 controllers also support constant-volume or variable-air volume supply fans. The Tracer AH540 is factory-mounted and the Tracer AH541 is field-installed.

Tracer graphical programming. See TGP.

Tracer LCI. Tracer LonTalk communication interface. A device that allows a certain type of controller to communicate using LonTalk. There are four LCIs. The Tracer LCI-V is for Voyager rooftop controllers. The Tracer LCI-R is for ReliaTel controllers on Precedent rooftop units. The Tracer LCI-I is for IntelliPak controllers. The Tracer LCI-C is for chiller controllers.

Tracer MP580/581 programmable controller. Programmable LonTalk controllers for a variety of HVAC applications. The Tracer MP580/581 may be factory-mounted on Trane Modular and T-Series Climate Changer air handlers. The Tracer MP581 is available for field installation. Tracer MP580/581 controllers use the Tracer graphical programming (TGP) language. See also TGP.

U

UCM. Unit control module. A Trane term for a microelectronic circuit board that is used to control HVAC equipment and link to an Integrated Comfort system.

unit control module (UCM). See UCM.

unit controller. A control device residing on a single piece of equipment. Unit controllers can be attached to a system-level controller, such as a SC. Trane advocates use of the LonTalk protocol at the unit level. Also called unit control module (UCM).

user interface (UI). A means for a user to interact with a computer. For example, a touch screen or the part of a software program with which the user interacts.

V

variable air volume (VAV). See VAV.

VariTrane air terminal devices. Trane’s pressure-independent VAV terminal units. The VariTrane product line is comprised of single-duct (cooling), dual-duct (cooling and heating), or fan-



Glossary

powered (parallel or series) units. Units may have electric or hydronic reheat. The VariTrane product line offers an optional DDC/VAV UCM for greater control, accuracy, and integration into the Trane Integrated Comfort system.

VAV. Variable air volume. An air distribution system that varies the volume of air supplied to a space to maintain acceptable comfort conditions.

VFC box. Dedicated ventilation systems use single-duct VAV boxes for ventilation flow control (called VFC boxes). These boxes are configured with either electric reheat or no reheat (shutoff boxes).

Voyager rooftop air conditioner. Trane’s light commercial unitary rooftop air conditioner that is available in sizes ranging from 3–50 tons of nominal cooling capacity. The Voyager rooftop comes standard with microelectronic DDC unit controller that makes the unit an integral part of the Trane Integrated Comfort system.

W

wink. In Rover Comm5 service tool, a procedure that matches a controller shown in the Rover main window with the actual controller. When the wink command is initiated in Rover, the LED on the controller winks for approximately 10 seconds.

XYZ

zone. The smallest area of control in an HVAC system. A zone is characterized by having a single thermostat or zone temperature sensor. A room served by a single VAV box is a zone. Several rooms served by the same VAV box also constitute a zone.

zone sensor. A device that measures the temperature in a space and sends it to a controller by means of a variable resistance signal.

BAS-APG007-EN, 12/15/2009 267

Index

Numerics24 Vac power

and LonTalk wiring, 38grounding, 38

Aadding VAV boxes to VAS after initial

setup, 108AH540/541

controller setup, 50–52AHU controllers, 11air and water balance, 152air handling unit (AHU), 6, 10

commissioning, 142configuration, 47connections, 44create a DAC object, 98pre-configuration checkout, 48

airflowmeasurement stations, 12recalculating total, 174setpoints, 15

appendixA, Controller flow settings

worksheet, 257B, MP580/581 network variable

inputs and profile associations, 260

C, level 4 wire specifications, 261applications, special, 181area

assign VAV members, 110reference temperature sensors,

112setup, 109

assignAreas as schedule members, 114LonTalk devices to Tracer

Summit objects, 115neuron IDs, 117VAVs as area members, 110

assumptions, 212, 215, 217, 220, 223, 226, 229, 231, 233, 235, 237

AHU, 214DAC, 214installation, 31SCC, 213scheduling, 212sequence of operation, 212

VAS, 214VV550/551, 214

Auto Changeover Setpoint, 58auto-commissioning, 14, 36, 141, 148,

165, 207, 208interpretation, 151open existing report, 150results, 149sequence, 148things to consider, 145using Rover service tool, 145using Tracer Summit, 147verify air valve operation, 151verify fan operation, 151verify reheat operation, 152VV550/551, 145

auxiliary temperature sensor, 13

BBACnet, creating objects, 116SC sizing, 16best practices, 58, 223, 243

24 Vac power supply, 15add VV550/551s as Area heating/

cooling members, 111AHU startup delay time, 109allow Area to use OA

temperature compensation, 130

Areaspace temperature input, 139unoccupied heating/cooling

setpoints, 124associating the CO2 sensor with

the XIF file, 102aux temp sensor for

commissioning, 145cold air and hot water for auto-

commissioning, 146commissioning, 141configure points before

modifying TGP, 63custom graphics, 119default ventilation value, 175determining common space

VAVs, 87disable duct static pressure

optimization for auto-commissioning, 147

discharge air temperature

sensor, 36duct static pressure optimization,

156sensor location, 44enable DAC profile for MP580/

581, 62for ventilation optimization

measure and control outdoor airflow, 164

install duct static pressure sensor at discharge of fan, 153

installing zone sensors, 32LCI-I controller setup, 54location labels during

commissioning, 117min and max Air Flow setpoints,

186monitoring CO2 levels, 14naming the VAS, 105night econ. and TOV initiator

check boxes for Area members, 111

no common space VAVs in dedicated ventilation, 185

outdoor airflow setpoint, 79power considerations for VV551

retrofit, 16scaling values, 80scheduled calibration, 121scheduling night economize, 134space temperature input for

Area, 112supply 50%-60% outdoor air to

the critical zone, 171templates for MP580/581

configuration, 63use default forArea setup, 113night cool unoccupied

differential, 127night heat unoccupied

differential, 125ventilation ratio limit of the AHU,

170Use Rover to enable DAC profile

on MP580/581, 99variable setpoint based on

dampers, 10VAS devices in the same SC, 16VAV air valve position high and

low limits, 156

268 BAS-APG007-EN, 12/15/2009

VAV aux heat check box, 108VAV calibration, 121VAV naming conventions, 101ventilation optimization system

level action, 164ventilation ratio limit of each VAV

setting, 176VFC boxes and multiple Areas,

187BMTX LonTalk wiring terminations,

42building automation system (BAS), 8building control unit, 8

Ccalibration, VAV, 121Changeover Setpoint, 58charts

DAC present value, 253SCC present value, 250

climate changer, 12CO2 levels, 14CO2-based demand controlled

ventilation, 159commissioning, 1, 8, 42, 97, 117, 122,

141, 210air handler, 142communications link, 142

common spaceVAV shutdown delay, 109VAVs, 106

communicating Present Value, 65communication

failure modes, 244networks, LonTalk, 9stub, 33

communicationsBACnet to LonTalk, 64linkcheckout without power, 42LonTalk termination resistors, 40open circuits, 144preliminary checkout, 142resistance measurements, 143short circuits, 144troubleshooting, 143Tracer Summit to MP580/581, 64

configuration, 5single-duct, 5

configureinputs, 63outputs, 63

variables, 63connections

air handler, 44control

smoke, 5, 191–205controller and equipment pairings,

11, 48controller setup

AH540541, 50–52LCI-I, 50–52LCI-I IntelliPak, 54–55LCI-R DAC, 53MP580/581, 53, 54, 61VFC box, 185

controllersnon-Trane functional capability,

17cooling and heating setpoints, 112CPL program

VAV_Alarm.cpl, 201creating BACnet objects, 116critical inputs

wiring, 12CSC, 12custom graphics, VAS, 118

DDAC

object, 47present value chart, 253profile, 10, 62

daisy-chain configurationLonTalk, 41, 42UCM wiring, 39

dampersTraq, 12

dedicated ventilation system, 12, 14, 181

setup, 184VFC box, 183

defaultvalues, verify in area, 112ventilation setpoint, 175

depressurize, 192diagnostic, 209

freeze protection, 209low air flow, 209ventilation flow control, 209

digital zone sensorterminations, 34, 35

discharge aircontrol, 28, 49sensor, VAV, 36temperature, 10

duct configurations, 5duct pressure setpoint optimization,

29duct static pressure, 10

optimization, 153best practices, 156DAC setup instructions, 154MP580/581 setup instructions,

154ductwork, 6

Eeffective ventilation setpoint, 164emergency override

request, 191, 195enable a DAC profile, 62energy consumption, minimizing,

171equipment and controller pairings,

11, 48EX2 expansion modules, 12exhaust fan, 6

Ffailure modes, communications, 244fan

exhaust, 6fire control panel, 191flow settings worksheet, 257flow tracking, 13, 58, 181, 188

negative pressure, 188positive pressure, 188setup, 189

Ggraphics, VAS

custom and standard, 118guidelines

for LonTalk wiring, 38

Hheating and cooling setpoints, 112heating/ventilation

operation for specific equipment/controllers, 225

hot water valvelocal heat, 37remote heat, 37terminations, 37

BAS-APG007-EN, 12/15/2009 269

howsmoke control works, 196the air handler works, 28the system works, 29the VAV boxes work, 20to use auto-commissioning, 207

Iimportant information

AHU and common space VAVs controlled by the VAS, 111

auto-commissioning, 208common space VAVs, 90configure as VAV check box, 101controlling common space VAVs,

91daytime warm-up, 131dedicated ventilation and night

economizing, 182determining the DAC object’s

present value, 95disabling reheat in VAV boxes,

125discharge air temperature sensor

and auto-commissioning, 146flow tracking boxes and VAS, 190further setup for optimization,

108how VAS determines AHU mode,

92Tracer SC VAS profile

requirements, 97manual output test and safeties,

210smoke control example, 191TGP and damper control, 80using Trane controllers, 9VAS responds to Area actions,

123VFC boxes and hot water reheat,

182VFC boxes with electric heat, 182

inputs, 63installing

LonTalk links, 38IntelliPak, 12isolating problem VAV boxes, 248

LLCI-I

controller setup, 50–52LCI-I IntelliPak

controller setup, 54–55LCI-R DAC

controller setup, 53LED

status, 209level 4 wire specifications, 261levels

CO2, 14library programs for Tracer Graphical

Programming (TGP)DischargeAirControl.tgp, 73FanControl.tgp, 68OA Damper Control with OA

CFM.tgp, 76setpoints.tgp, 71

line voltage power, 11locations, network variables for

MP580/581, 64LonMark DAC profile (8610), 10LonMark™, 18LonTalk, 8

and 24 Vac power wires, 38choose an AHU that

communicates using, 10comm linkdigital zone sensor terminations,

34communication link topology, 39communication networks, 9daisy-chain configuration, 41, 42DDC controller on VAV box, 13DDC controller on VAV box

(Tracer VV550/551, 13network variable associations, 64polarity sensitivity, 38termination resistors, 38, 40VAV air system, 16VV550/551 terminations, 33wiring guidelines, 16, 38zone sensor terminations, 33

Mmaintenance, 207manual output test, 207, 209

initiate, 210maximum air flow, 186measured primary airflow, 164measurement

airflow, 12members

VAS, 105minimum

air flow, 186outdoor air control, 29

modesstandard operating, 124

modulesEX2 expansion, 12

monitoringCO2 levels, 14

MP580/581configure inputs, outputs,

variables, 62controller setup, 53, 54, 61network variable locations, 64programming, 61

Nnaming devices, 51National Electrical Code, 38network variable

inputs, MP580/581, 260network variable locations, 64networks

termination resistors, 38wiring, 38

neuron ID, assigning, 117night

cool, 127, 128economize, 134, 241heat, 125, 127heat/cool

cooling, 233heating, 235, 237, 239

setback, 124non-Trane controllers

DAC, 17, 18functional capability, 17SCC, 17

normal start, 223nviApplicMode, 65nviOccSchedule, 65

Oobject definitions, 97

AHU, 98assign LonTalk devices, 115BACnet, 116DAC profiles for MP580/581, 62MP580/581, 99SCC for VAV boxes, 100

objectsDAC, 47

occupancy sensor, 14occupied standby ventilation, 186open circuit, comm link, 144

270 BAS-APG007-EN, 12/15/2009

optimal startcooling, 215heating (central heat with no

local heat), 217heating (local heat with central

fan), 220optimal stop, 229optimization

duct pressure setpoint, 29duct pressure, possible

problems, 248duct static pressure, 153ventilation, 5, 157ventilation enhancement, 176ventilation, possible problems,

249outdoor air, 6, 58, 72, 73, 80, 112, 181,

249output testing, manual, 207, 209outputs, 63

Ppairings

equipment and controllers, 11, 48parallel fan powered VAV, 6, 7polarity sensitivity, 38power

considerations, 43line voltage, 11

pre-configuration checkout for air handlers, 48

Present Value, 65chart

DAC, 253SCC, 250

pressureduct static, 10, 153negative flow tracking, 188positive flow tracking, 188possible duct pressure

optimization problems, 248static

sensor control, 49pressurize, 192primary airflow, measured, 164problems

space temperature summary, 249

VAV boxes, isolating, 248profile associations, MP580/581, 260profile, DAC, 62programming, MP580/581, 61purge, 193

Rratio

limits, ventilation, 170ventilation, 164

recalculating total airflow, 174referencers

setup, 106temperature sensors to the area,

112requirements

LonTalk wiring, 38National Electrical Code, 38polarity, 38

resistors, LonTalk link termination, 40retrofit kit for VV551, 15RJ-11 jack, 32, 50, 56Rover service tool, 8, 51, 55, 61, 67,

99, 142, 144, 145, 158, 183, 209, 210auto-commissioning VAVs, 145

SSCC

objects, 100present value chart, 250

scenariossequence of operation, 211

schedules, 114sensors

occupancy, 14reference temperature to area,

112space temperature, 12static pressure, 153zone, 13, 32

sequence of operationcommunication loss, 243for standard applications, 212general assumptions, 212night economize, 241night heat/cool cooling, 233night heat/cool heating

(with central heat), 235(with local heat and central

fan), 237(with local heat and no central

fan), 239normal start, 223optimal start cooling, 215optimal start heating

(central heat used and local heat not used), 217

(local heat with a central fan),

220optimal stop, 229parallel fan powered terminal

units, 23–25scenarios, 211series fan powered terminal

units, 25–27single duct VAV terminal units,

20–23summary table, 245timed override, 226unoccupied, 231

series fan powered VAV, 7setpoint

auto changeover, 58default ventilation, 175

setpointsairflow, 15effective ventilation, 164heating and cooling, 112

setupAH540/541 controller, 50–52areas, 109flow tracking, 189LCI-I controller, 50–52LCI-I IntelliPak controller, 54–55LCI-R DAC controller, 53MP580/581 controller, 53, 54, 61referencers, 106VAS, 105VFC box controller, 185

short circuit, communication link, 144shutdown, 193shutdown delay, common space

VAV, 109single-duct configurations, 5sizing the SC, 16smoke control, 5, 181, 191–205

equipment and controller behavior, 194

smoke control modedepressurize, 192pressurize, 192purge, 193shutdown, 193

space temperaturesensor, 12summary problems, 249

special applications, 181standard graphics, VAS, 118

BAS-APG007-EN, 12/15/2009 271

standard operating modesnight cool, 127night economize, 134night heat, 125, 127night setback, 124operating modes

standard, 124static pressure sensor

control, 49location, 44, 153

status LED, 209system energy consumption curve,

171

Ttemperature

auxiliary sensor, 13discharge air, 10sensors

reference to area, 112space sensor, 12

termination resistors for LonTalk links, 38, 40

testing, manual output, 207, 209timed override, 226topology

alternate daisy chain, 39daisy chain, 39

total airflow, recalculating, 174Tracer Graphical Programming

(TGP), 67Tracer Summit

auto-commissioning, 147object definitions, 97workstation, 8

Traq dampers, 12troubleshooting, 211

Uuniversal inputs, 191unoccupied sequence of operation,

231

Vvariables, 63VAS

adding VAV boxes after initial setup, 108

assign common space VAVs, 106custom graphics, 118referencer setup, 106setup, 105standard graphics, 118

VAVadding to VAS, 108assign to areas, 110boxes, 6calibration, 121Commercial Voyager, 12common space, 106common space shutdown delay,

109discharge air sensor, 36isolating problems, 248parallel fan powered, 6, 7reheat, 7series fan powered, 7shut off, 6

VAV_Alarm.cpl, 201VCCF, 15VCWF, 15ventilation, 8, 12, 14, 20, 58

dedicated, 14dedicated systems, 181flow, 13flow control, 20heating

operation for specific equipment/controllers, 225

occupied standby, 186optimization, 5, 153, 157

CO2-based demand controlled ventilation, 159

enhancement, 176fixed ventilation, 157occupancy based ventilation,

158sending min flow to an MP580/

581 controlled AHU, 169sending min flow to the DAC

AHU, 168system level action, 164, 173,

175zone level action, 157

possible optimization problems, 249

ratio, 164limit for each VAV, 171limit of the AHU, 170

referencer for VFC box, 186setpoint, effective, 164

ventilation optimizationscheduled ventilation, 160

ventilation ratio limits, 170

ventilation systemdedicated, 12

VFC box, 14, 183controller setup, 185hot water use, 14

voltageline, 11

VV551 retrofit kit, 15

Wwire specifications, level 4, 261wiring

critical inputs, 12daisy-chain configuration for

LonTalk, 42distance

digital zone sensor, 34discharge air temperature

sensor, 36wireless receiver, 35zone sensor, 33

LonTalk links, 38LonTalk wiring guidelines, 38UCM communications

daisy chain configuration, 39termination resistors for

LonTalk links, 40

Zzone sensors, 13

hard-wired, 32terminations, 33with communication stub, 33with digital display, 33

272 BAS-APG007-EN, 12/15/2009

www.trane.com

For more information, contact your local Trane office or e-mail us at [email protected]

Literature Order Number BAS-APG007-EN

Date December 2009

Supersedes New

Trane has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice.

Trane and the Trane logo are trademarks of Trane in the United States and other countries. All trademarks referenced in this document are the trademarks of their respective owners.

Bas-Apg007-En 12012009 Air Systems

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