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BASICS OF BALLAST TECHNOLOGY. Created by the U.S. Department of Energy Rebuild America Business Partners and Advanced Transformer. Ballast Design. Design Basics. A Rapid Start Ballast Must Perform the Following Four Functions:. Electrode Preheat Voltage Lamp Ignition Voltage
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BASICS OF BALLAST TECHNOLOGY Created by the U.S. Department of Energy Rebuild America Business Partners and Advanced Transformer
Design Basics A Rapid Start Ballast Must Perform the Following Four Functions: • Electrode Preheat Voltage • Lamp Ignition Voltage • Regulate Lamp Current • Regulate Lamp Voltage
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 Lamp • Ignites The Lamp • Begins Lamp Current Flow • 200 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 Current • Lamp 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 Output • Maintains Correct Electrode Temperature • Too Little Will Decrease Lamp Life • Too Much Will Decrease Lamp Life
Starting Methods • Rapid Start • Rapid 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/Circuiting • Rapid 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 Hours • Lamp 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 Wattage • Ballast Efficacy Factor • Lamp Current Crest Factor • Power Factor • Harmonic Distortion • Electromagnetic/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 areDifferent! • ANSI, Open, Enclosed, ???
Input Wattage Comparison • Four Lamp F32T8 Electronic Ballast • ANSI Input wattage • 112 Watts • Open Fixture Wattage • 109 • Enclosed Fixture Wattage • 106 • Applicable to 1,2,3,4 Lamp Ballasts • Two Lamp T8 Electronic • Advance RS - 60 w ANSI • Competitor - 60 w OPEN ( equiv. to 62/63W ANSI) • Same Rated Light Output
Ballast Efficacy Factor • Ballast 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 Start • Typical Magnetic - 1.6-1.7 • Typical Electronic - 1.5-1.6
Power Factor • Determines the Relationship Between the Voltage and the Current Waveforms • Normal Power Factor is 50-60% • High Power Factor is >= 90% • Magnetic Ballasts are Typically 95%-99% PF • Electronic Ballasts are Typically 97-99% PF • No Discernible Difference • Be 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 Resistor • Magnetic Ballasts Have it • Electronic Ballasts Have it • Computers and ASD’s Have MUCH MORE!!
Effects of Harmonic Distortion • Overheating of Phase Conductors • Circuit Breaker Tripping • Transformer Overheating • Overloading of Neutral Conductor • A Properly Designed Lighting System Will Cause None of This!
Electronic Power Supply Linear & Non-Linear Loads
Distortion of the Fundamental Waveform with Harmonic Waveforms
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 B - 120 Degrees Phase A Triplen Harmonics Add on the Neutral Phase C - 240 Degrees
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 Current • Typical 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 Systems • Local RF Transmissions • Library Book Security Systems • GFI Circuits • Infrared Control Devices • EMI/RFI Sensitive Locations High Efficiency PowrKut Low Frequency Electronic Ballasts are Recommended in These Applications.
System Performance Comparisons Several Lamp and Ballast Choices • T8 vs. T10 vs. T12 • Magnetic vs. Hybrid vs. Electronic
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 Hz • Hybrid - Electrode Cutout - Operates at 60 Hz • Electronic - High Frequency - Operates >20,000 Hz
Magnetic Ballasts • Most Common • Steel • Copper • Core & Coil • 60 Hz Lamp Operation • Lamp Flicker not Noticed • Audible Noise, Sound Rated A • Lowest 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 Protection • Rectification • 60 Hz AC to DC • High Frequency Converter • DC to 20,000 Hz AC • Power Factor Correction • THD Correction • Output to Lamp
Electronic Ballast • Operates at High Frequency • 20,000 Hz to 60,000 Hz • 6-16% Lamp Efficacy Gain • Combines Electronic Components with Small Magnetic Transformers • No “Fully Electronic” Ballast • Highest Efficiency • Highest Initial Cost • No Lamp Flicker • 25-75% 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 • Daylighting • Occupancy Sensing • Lumen Maintenance • Manual Control • Time of Day Lighting Schedule • Integrated Building Management System