16-SAMSS-521

Materials System Specification

16-SAMSS-521 12 November 2008 Indoor Automatic Transfer Switch - Low Voltage

Electrical Substations Equipment Standards Committee Members Ishwait, Basel A., Chairman Ghamdi, Mohammed Ahmed, Vice Chairman Nazzawi, Abdullah Omar Fayez, Hamad Abdullah Gopal, Uarutharaja Ojan, Jawad Ali Helfrich, Cory Allan Refai, Jobran Ali Sheef, Jaafar Abdullah Ramadhan, Mohammad Jafar Maghrabi, Ibrahim Mohammad Hartman, Ralph August

Saudi Aramco DeskTop Standards Table of Contents 1 Scope............................................................ 2 2 Conflicts and Deviations............................... 2 3 References.................................................... 2 4 Definitions..................................................... 3 5 General......................................................... 4 6 Rating............................................................ 5 7 Service Conditions........................................ 5 8 Enclosures.................................................... 5 9 Conductors.................................................... 6 10 Switching Devices......................................... 6 11 Metering........................................................ 6 12 Nameplates................................................... 7 Data Schedule 1.................................................. 8

Previous Issue: 14 October 2008 Next Planned Update: 14 October 2013 Revised paragraphs are indicated in the right margin of 8 Primary contact: Ishwait, Basel A. on 966-3-8760288

Copyright©Saudi Aramco 2008. All rights reserved.

Document Responsibility: Electrical Substations Equipment 16-SAMSS-521 Issue Date: 12 November 2008 Next Planned Update: 14 October 2013 Indoor Automatic Transfer Switch - Low Voltage

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1 Scope

This Specification defines the mandatory requirements for indoor, low voltage automatic and non-automatic transfer switches rated a maximum of 600 V and built to either the International Electrotechnical Commission (IEC) or North American (NA) based Standards. This specification covers completely enclosed transfer switches and also open types intended for use in other equipment such as controlgear and switchboards.

2 Conflicts and Deviations

2.1 If there are any conflicts between this Specification and associated purchasing, project or engineering documents, this specification shall take precedence.

2.2 Direct all requests to deviate from this Specification in writing to the Company or Buyer Representative, who shall follow internal company waiver procedure.

2.3 The designation "Commentary" is used to label a sub-paragraph that contains comments that are explanatory or advisory. These comments are not mandatory, except to the extent that they explain mandatory requirements contained in this SAMSS.

3 References

Material or equipment supplied to this specification shall comply with the latest edition of the references listed below, unless otherwise noted.

3.1 Saudi Aramco References

Saudi Aramco Materials System Specifications

16-SAMSS-503 Low Voltage Controlgear

16-SAMSS-519 Indoor Switchboard – Low Voltage

3.2 Industry Codes and Standards

National Electrical Manufacturers Association

NEMA PB 2 Deadfront Distribution Switchboards

NEMA ICS 10 AC Transfer Switch Equipment

NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum)

http://standards/docs/SAMSS/PDF/16-SAMSS-503.pdf



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International Electrotechnical Commission

IEC 60947-6-1 Low-Voltage Switchgear and Controlgear, Part 6-1: Multiple Function Equipment – Automatic Transfer Switching Equipment

Underwriters Laboratories, Inc.

UL 1008 Transfer Switch Equipment

4 Definitions

Closed-Transition: Main circuit contacts overlap providing a make-before-break operation between the emergency and normal power sources.

Conductor: All material, devices and parts which are expected to carry current as part of their normal function (e.g., cable, bus, relay contacts, terminal block studs, etc.).

Controlgear: Equipment manufactured to either 16-SAMSS-503 (Low Voltage Controlgear).

Deadfront: As per the NEMA PB 2 definition, a switchboard which has no exposed live parts on the front.

Delayed-Transition: Same as the Open-Transition except with an adjustable time delay between the break-before-make operation.

Front Accessible: As per the NEMA PB 2 definition, a switchboard in which all bus and device connections are accessible from the front. If necessary, a limited number of devices shall be permitted to be removed to achieve this accessibility.

Line: The terminal of the switching device to which the source of voltage/power is connected.

Load: The terminal of the switching device to which the equipment receiving the voltage/power is connected.

Low Voltage: Means a voltage level of less than 1000 volts.

Commentary Note:

For this equipment in the intended application "low voltage" is essentially limited to 600 V.

Main Circuit: All the conductive parts of an assembly included in a circuit which is intended to transmit electrical energy to the connected loads.

Open-Transition: Main circuit contacts do not overlap providing a break-before-make operation between the normal and emergency power sources.



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PEM: Parent Equipment Manufacturer. The manufacturer who designed the equipment and who confirmed the design performance through certified design/type tests. This manufacturer (1) has the legal authority to license the assembly of this equipment to others (2) is responsible for the technical performance of the equipment and (3) will be able to provide after-sales support and parts for the equipment.

Switchboard: Equipment manufactured per 16-SAMSS-519.

Switching Device: A device designed to make or break current.

Transfer Switch or TS: The assembly of switching devices and associated control and auxiliary equipment which controls and distributes power to the output of the transfer switch.

5 General

5.1 Terms in bold font are defined within Section 3.

5.2 The transfer switch shall also fully comply with either the "NA Supplement" or the "IEC Supplement" as specified within Data Schedule 1. Transfer switches built utilizing a mixture of Standards (e.g., devices only tested and rated by IEC within a NEMA tested and rated controlgear assembly) is unacceptable

5.3 The TS shall be equipped with all necessary supplementary protective/interrupting devices (e.g. fuses) necessary to ensure the short circuit rating of the TS is compatible with the equipment to which it is connected.

5.4 Refer to Section 2 for direction on conflict resolution between documents. For example, if there are any conflicts between this Specification and associated project or engineering documents, this specification shall take precedence.

5.5 All requirements of this specification must be implemented using standard designs which have been approved, have been fully tested and are fully supported by the PEM.

5.6 Whenever this specification requires compliance to a third party document (e.g., ANSI, UL, etc.), this document shall be the edition which was in effect on the date of the Quotation Request.

5.7 This specification shall take precedence over any referenced third party document.

5.8 All temperatures expressed within this specification are in Celsius units



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(NA Supplement)

5.NA1 Transfer switch shall be manufactured per NEMA ICS 10 and comply with UL 1008.

(IEC Supplement)

5.IEC1 Transfer switch shall be manufactured per IEC 60947-6-1.

6 Rating

6.1 Rated Duty: Continuous

6.2 Short Circuit rating (minimum): 10 kA rms

6.3 The transfer switch shall be designed and rated for connection to the type of interrupting devices indicated within Data Schedule 1.

7 Service Conditions

Transfer switch shall be suitable for continuous operation under the following service conditions:

7.1 Ambient air temperature:

a) A maximum of 40 degrees.

b) A minimum of 0 degrees.

c) Average temperature, measured over a period of 1 month, is a maximum of 30 degrees.

7.2 Relative humidity (average value):

a) For a period of 24 hours, does not exceed 95%.

b) For a period of 1 month, does not exceed 90%.

7.3 Altitude is less than 1000 meters, unless a higher altitude is specified within Data Schedule 1.

8 Enclosures

8.1 Shall be front accessible, deadfront, completely enclosed, and free standing.

8.2 Space heaters shall not be installed within the transfer switch enclosure.


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9 Conductors

9.1 All conductors shall be copper, silver or alloys of these materials, with the following exceptions:

9.1.1 Parts which are internal to a pre-manufactured device (e.g., internals of circuit breaker).

9.1.2 Connectors supplied as integral parts or components of manufactured equipment such as molded case circuit breakers provided the connectors are approved for copper conductors.

9.1.3 Plating of the copper, silver or copper/silver alloy base conductor material is acceptable.

9.2 Bus bar mating surfaces shall be either silver or tin plated.

9.3 If a neutral has been specified, a neutral conductor system shall be provided which can continuously carry the same current as the phase conductors without exceeding the temperature rise limitations.

10 Switching Devices

When a bypass switch has been specified in Data Schedule 1, it shall function as follows:

10.1 Shunt the service around the transfer switch without interrupting power to the load

10.2 Allow the TS to be electrically tested and operated without interrupting power to the load.

10.3 Electrically isolate the TS from both sources of power and the load conductors to permit inspections and maintenance. Under this condition, the TS should be able to be worked on at a detailed level with no danger of contacting electrically energized parts.

10.4 While the TS is electrically isolated as described above, the TS shall be operable manually.

11 Metering

11.1 The transfer switch shall be equipped with voltage indication meeting the following requirements:


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11.1.1 Shall give an indication on all three phases of the line side of both the primary and alternate power source.

11.1.2 Metering device shall operate at a maximum voltage of 120 VAC.

11.2 The transfer switch shall be equipped with amperage indication meeting the following requirements:

11.2.1 Shall give an indication on at least one phase of the main circuit of the load side of the TS.

11.2.2 Metering devices shall operate at a maximum current of 25 A.

12 Nameplates

12.1 White nameplates with black lettering shall be provided to identify the panelboard with the tag number indicated within Data Schedule 1.

12.2 The Manufacturer's shop order number, date, and catalog designation should be indicated on the controlgear nameplate in addition to the nameplate information required by the Standards indicated within the Supplement.

Revision Summary 14 October 2008 Editorial revision to replace Electrical Substations Equipment Standards Committee

Chairman and Vice Chairman. Revised the "Next Planned Update. 12 November 2008 Editorial revision.


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Data Schedule 1 16-SAMSS-521: Indoor Transfer Switch – Low Voltage

(Information to be supplied to Supplier) Line #

1 Buyer's Quotation Request/ Purchase Order No.

______________________________________________________

2 Buyer's B.I./J.O. No.________, Line Item No.___________

3 Tag No.__________________________

Service information:

20 As indicated on the attached reference documents ___ or the following:

25 System frequency: 60 Hz _____, 50 Hz _____

27 Number of Phases/Wires 1/2___, 1/3___, 3/3 ____, 3/4 ___

29 Rated Current: _______ A

31 System Grounding Method: Solid_____, Resistance______

33 Manufacturer & model of interrupting/protective devices feeding transfer switch:

35 Primary Source: _____________________________________________

37 Short Circuit level: _______kA.

39 Secondary Source: ___________________________________________

41 Short Circuit level: _______kA.

43 Rated voltage: _________ (600V maximum)

45 Site altitude (if greater than 1000 meters) _________ meters

47 Operation Type(1): Automatic ____, Non-Automatic _____

49 Open-Transition ____, Delayed-Transition ____, Closed-Transition(2) ____

51 Maintenance Bypass Switch Required(1): YES ____, NO _____

53 Switched or overlapping neutral contacts Required(1): YES ____, NO _____

56 Main circuit supply conductor connectors (if applicable):

57 Supplied by Supplier: YES ( ), NO ( )

58 If YES: No./phase and size of main circuit supply conductors:

59 _____ /ph., ______ AWG, MCM, mm² Notes to Buyer: (1) Refer to SAES-P-116 for criteria. (2) Use of Closed-Transition requires approval per SAES-P-116.

16-SAMSS-521

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