BASICS OF BALLAST TECHNOLOGY

Created by the U.S. Department of Energy Rebuild America Business

Partners and

Advanced Transformer

Ballast Design

Design Basics

Electrode Preheat VoltageLamp Ignition VoltageRegulate Lamp CurrentRegulate Lamp Voltage

A Rapid Start Ballast Must Perform the Following Four Functions:

Electrode Voltage“Heater Voltage” Applied Across

The Pins of a Rapid Start Lamp Approximately 3.5 Volts For F40T12, F32T8 Not Present For Instant Start Lamps

Heats Electrode to Begin Thermal Emission of Electrons Voltage Across Pins Electrode Current Flow

Thermal Emission Lamp Ready to Start

.5 to 1 Second

Lamp Voltage Requirements

Voltage Applied Across The LampIgnites The Lamp

Begins Lamp Current Flow200 Volts For F40T12

Higher For F32T8 Higher or Lower Than 120/277 U.S. Line

Voltage Ballast Acts as a Transformer

Voltage Must Be Reduced After Lamp Ignition 98 Volts for F40T12 137 Volts for F32T8

Fluorescent Lamp CurrentLamp Will Draw Excessive Current

Unless Regulated Lamp Failure in 1/100 th of a Second Ballast Limits Current Flow

430 ma For F40T12 265 ma for F32T8

Maintains Proper Light OutputMaintains Correct Electrode

Temperature Too Little Will Decrease Lamp Life Too Much Will Decrease Lamp Life

Starting MethodsRapid StartRapid Start - Electrode Cutout (PowrKut)

Saves 1.5 Watts Per Electrode No Reduction in Lamp Life

Rapid Start - Soft Start “Ramps” Up Ignition Voltage Increases Lamp Life Exclusive - Advance Mark V/Mark VII

Instant Start No Electrode Voltage, Higher Ignition Voltage Possible Lamp Life Reduction if Heavily Cycled Highest Efficiency

Lamp Starting/CircuitingRapid Start Ballasts Generally

Have Their Lamps Wired in Series When One Lamp Burns Out, all Lamps are

Extinguished

Instant Start Lamps Generally Have Their Lamps Wired in Parallel

When One Lamp Burns Out, the Remaining Lamps Stay On

Lamp Life IES LM-40 Measurement Procedure

3 Hours On, 20 Minutes OFF Rapid Starting of a RS Lamp will Achieve a 20,000

Hour Lamp Life Instant Starting of a RS Lamp will Reduce Lamp Life

to 15,000 HoursLamp Life Equal at 12-16 Hours Per

Start 25,000 to 30,000 Hours

Occupancy Sensors Up to 50% Lamp Life Reduction Shorter Life, But in Fixture Same Amount of Time Tremendous Energy Savings Potential

Performance Characteristics

Ballast Factor Input WattageBallast Efficacy FactorLamp Current Crest FactorPower FactorHarmonic DistortionElectromagnetic/Radio Frequency

Interference

Ballast Factor - Light Output

Delivered Lumens/Rated Lumens 2700/3000 = .90 BF 2800 rated x .88 BF = 2464 delivered lumens

ANSI Standards .925 Minimum for Magnetic .85 Minimum for Electronic

Typical Values .95 Magnetic .88 - .92 Electronic

Thermal Effects Allow Difference Higher Lamp Bulb Wall Temperature When Operated in

an Enclosed Fixture Reduces Light Output (and Watts)

Electronic Ballast Factor Options

Higher Ballast Factor - Higher Watts Lower Ballast Factor - Fewer Watts Normal Light Output 85-92 % BF Reduced Light Output 75-84% BF

May Cause Lamp Life Reduction High Light Output 110-115% BF

Rated Lamp Current Very High Light Output 125- 130% BF

Will Cause Lamp Life Reduction

Efficiency Vs. Efficacy

Efficiency Power Out/Power In Ballast Efficiency

Watts Loss Magnetic - 20 W EE Mag - 10 W Low Freq. Elec. (Hybrid) - 8 W High Frequency Elec. - 5-8 W

Efficiency Vs. Efficacy

Efficacy Un-like Terms Lumens/Watt (LPW) Miles/Gallon (MPG)

LPW of the Lamp of the System

Input Wattage

Input Wattage to the Lamp/Ballast SYSTEM Separate Wattages are Meaningless Different Wattages for Same System

ANSI Open Fixture Enclosed Fixture

ANSI Standard is Only Repeatable Measurement Wattage Decrease Follows Light Output Manufacturer’s Catalogs are Different!

ANSI, Open, Enclosed, ???

Input Wattage ComparisonFour Lamp F32T8 Electronic BallastANSI Input wattage

112 WattsOpen Fixture Wattage

109Enclosed Fixture Wattage

106Applicable to 1,2,3,4 Lamp BallastsTwo Lamp T8 Electronic

Advance RS - 60 w ANSI Competitor - 60 w OPEN ( equiv. to 62/63W ANSI) Same Rated Light Output

Ballast Efficacy FactorBallast Factor/ANSI Input Watts

95BF/96W = .99 BEF Magnetic T12 90BF/72W = 1.25 BEF Electronic T12

Basis of Legislation 1.06 BEF Minimum for (2) F40T12 Lamps @120V

Measurement of Efficacy of Lamp/Ballast System

Use Lumens per Watt (LPW) to Compare DIFFERENT Lamp/Ballast SYSTEMS 60 LPW - F40T12 Magnetic System 85 LPW - F32T8 Electronic System

Lamp Current Crest Factor

Ipeak divided by Irms

Measurement of “Smoothness” of Lamp Current Waveform

Sine Wave = 1.414 ANSI Maximum = 1.7 Rapid StartTypical Magnetic - 1.6-1.7Typical Electronic - 1.5-1.6

Power FactorDetermines the Relationship Between the

Voltage and the Current WaveformsNormal Power Factor is 50-60%High Power Factor is >= 90%Magnetic Ballasts are Typically 95%-99% PFElectronic Ballasts are Typically 97-99% PFNo Discernible DifferenceBe Careful of Large Load Reductions!

Reflectors Delamping

Harmonic Distortion

Created by Non-Linear Loads Computer Power Supplies Adjustable Speed Drives Arc-Discharge Lighting

Every Device Except a ResistorMagnetic Ballasts Have itElectronic Ballasts Have itComputers and ASD’s Have MUCH

MORE!!

Effects of Harmonic Distortion

Overheating of Phase Conductors Circuit Breaker TrippingTransformer OverheatingOverloading of Neutral ConductorA Properly Designed Lighting

System Will Cause None of This!

Linear & Non-Linear Loads

Electronic Power Supply

Distortion of the Fundamental Waveform with Harmonic Waveforms

3 Phase Supply Circuit

Fundamental (60 Hz) Current Addition

Phase A Phase B - 120 Degrees

Phase C - 240 Degrees

Fundamental Current Cancels on the Neutral

Harmonic Current Addition

Phase A

-1

-0 .8

-0 .6

-0 .4

-0 .2

0

0 .2

0 .4

0 .6

0 .8

1

Phase B - 120 Degrees

-1

-0 .8

-0 .6

-0 .4

-0 .2

0

0 .2

0 .4

0 .6

0 .8

1

Phase C - 240 Degrees

-1

-0 .8

-0 .6

-0 .4

-0 .2

0

0 .2

0 .4

0 .6

0 .8

1

Triplen Harmonics Add on the Neutral

-1

-0 .8

-0 .6

-0 .4

-0 .2

0

0 .2

0 .4

0 .6

0 .8

1

Harmonic Percentages

ANSI Standard is 32%IEC Standard is 34.8%Magnetic Ballast

Typically 20-30%Electronic Ballast

Typically 10-20%Magnetic Ballasts Draw More CurrentTypical Electronic T8 has 50% Less

Harmonic Current Than Magnetic T12

Electromagnetic/ Radio Frequency Interference

Electronic Ballasts Designed to meet U.S. FCC Class A Standards

Class A Commercial/Industrial Requirements 450 - 2000 KHz 60 dB 2.0 - 30 MHz 71 dB

Class B Residential Requirements 450 KHz - 30 MHZ 48 dB

Electronic Ballasts are Class A, and Could Interfere with Residential Devices Put on Separate Circuits Place Farther Away From One Another

High Frequency Electronic Application Concerns

Power Line Carrier SystemsLocal RF TransmissionsLibrary Book Security SystemsGFI Circuits Infrared Control DevicesEMI/RFI Sensitive LocationsHigh Efficiency PowrKut Low Frequency

Electronic Ballasts are Recommended in These Applications.

System Performance Comparisons

T8 vs. T10 vs. T12Magnetic vs. Hybrid vs.

Electronic

Several Lamp and Ballast Choices

Lamp Comparisons

F40T12 3050Lm/40w = 76.3 LPW

F40T12/34w 2750Lm/34w = 80.9 LPW

F32T8 2800Lm/32w = 87.5 LPW 3050Lm/32w = 95.3 LPW

F40T10 3700Lm/40w = 92.5 LPW

Ballast Choices

Magnetic - Operates at 60 HzHybrid - Electrode Cutout -

Operates at 60 HzElectronic - High Frequency -

Operates >20,000 Hz

Magnetic Ballasts

Most CommonSteelCopperCore & Coil60 Hz Lamp OperationLamp Flicker not Noticed Audible Noise, Sound Rated ALowest Initial Cost

Hybrid Ballasts Core & Coil Electronic Circuit Provides Electrode Voltage Electrode Heat Removed After Lamp Ignition

Saves 1.5 Watts per Electrode Electronic Circuit Provides Stable Voltage

Rated Lamp Life or BETTER No Harmful Lamp Effects 1.4-1.5 Crest Factor

97-99% as Efficient as Electronic Rapid Start Lower Initial Cost Than Electronic

Electronic Power Flow Input

EMI Filter, Transient ProtectionRectification

60 Hz AC to DCHigh Frequency Converter

DC to 20,000 Hz AC Power Factor Correction THD Correction

Output to Lamp

Electronic BallastOperates at High Frequency

20,000 Hz to 60,000 Hz6-16% Lamp Efficacy GainCombines Electronic Components with

Small Magnetic Transformers No “Fully Electronic” Ballast

Highest EfficiencyHighest Initial CostNo Lamp Flicker25-75% Less Noise

Electronic Dimming Systems

Architectural 100 - 1% Dimming Expensive

Energy Management 100%-20% Dimming

Code Requirements 100%/50% Step Dimming 5 Level Step Dimming

Energy Management Dimming

DaylightingOccupancy SensingLumen MaintenanceManual ControlTime of Day Lighting

ScheduleIntegrated Building

Management System