AC (Alternating Current)
Current that passes from the generator in one direction and then the other, alternately.
Ambient sound levels
Background noise generated by electrical and mechanical equipment operating in a building. Low ambient sound levels are desirable for hospitals, libraries and similar applications where high noise levels are unacceptable.
Ambient Temperature
The temperature of the atmosphere of surrounding environment.
Amperes ("Amps")
A measure of electrical current.
ANSI (American National Standards Institute)
Group that generates product performance standards for many U.S. industries.
ANSI Watts
Measurement of electrical power used by the ballast and lamps when tested per ANSI standards.
Anti-Arc Circuit
Circuitry used to restart the lamps without resetting the power to the ballast.
Anti-Striation Circuit
Circuitry used to prevent striations or spiraling in energy saving lamps due to low temperature or low current operation
Arc (Lamp)
Intense luminous discharge formed by the passage of electric current across a space between electrodes.
Arcing of output leads
Generation of an electrical arc between output leads of a ballast or output leads to ground.
Asphalt silica sand mixture
A mixture of asphalt and silica sand used to fill the cases of electromagnetic and electronic ballasts to dampen sound, protect from moisture, improve heat removal and increase reliability.
Auto-Restrike
Circuitry used to restart the lamps without resetting the power to the ballast.
Autotransformer
A tapped winding transformer that changes the voltage available locally to the voltage required by a particular load.
5-Tap
An HID ballast that allows for a choice of five different input voltages.
AllnGaP
The preferred LED (Light Emitting Diode) chip technology containing Aluminum, Indium, Gallium, and Phosphorous to produce red, orange and amber-colors.
Ballast
Device for starting and regulating fluorescent and high intensity discharge lamps.
Ballast Cycling
Undesirable condition under which the ballast turns lamps on and off (cycles) due to the overheating of the thermal switch inside the ballast. This may be due to incorrect lamps, improper voltage being supplied, high ambient temperature around the fixture, or the early stage of ballast failure.
Ballast Efficacy Factor (BEF)
Measure used to compare various lighting systems based upon light output and power input. Higher BEF is favorable. BEF = Ballast Factor x 100 / Input Watts
Ballast Factor (BF)
Measure of light output from lamp operated by commercial ballast, as compared to a laboratory standard reference ballast.
Ballast Losses
Power that is supplied to the ballast but is not converted into light energy.
Ballast Noise "Hum"
Sound made by operating Core & Coil assemblies in both electromagnetic and electronic ballasts, generated by the vibration of laminations in the electromagnetic field that transforms the voltage and current used by discharge lamps. The sound made by high frequency electronic ballasts is lower and any noise made by models with electronic power factor correction circuits is inaudible.
Ballast Performance Factors
Measurements that allow the comparison of various ballasts in terms of their power efficiency and ability to produce light.
Ballast Regulation
The ability of a ballast to control lamp wattage (and therefore light output) when subject to changes in line voltage.
Bottom Exit
A configuration with leads or a wire-trap on the bottom or base of the ballast. This type of Configuration is usually used when the ballast is mounted on to a junction box plate.
Burn-in test
Test performed on electronic product that simulates conditions encountered in actual operation to weed out initial failures.
Bin
In LED's, the systematic dividing of distribution of performance parameters (Flux, Color or CCT, and Vf) in to smaller groups that meet aesthetic requirements of the assembly.
Binning
In LED's, the subdivision of the manufactured "distribution" into bins common operating parts (color, flux, forward voltage).
Canadian Energy Standards
Indicates that ballast complies with Canadian Energy Standards and meets the requirements of CAN/CSA-C654-M91.
Canadian Standards Association (CSA)
Association that generates product performance and safety standards for many Canadian industries.
Capacitor
Device in ballast that stores electrical energy.
Centigrade (C)
Celsius temperature scale where 0°C = 32°F and 100°C = 212°F.
Circle-E
Marking on ballast that shows compliance with Federal Ballast Energy Law (Public Law 100-357).
Circuit Ballast
Reactor, high reactance CWTA, CWE, Reg
Coil
Windings of copper or aluminum wire around the core in electromagnetic ballast that transforms the voltage from input to output.
Color Rendering Index (CRI)
An international system used to rate a lamp's ability to render object color. The higher the CR, the better colors appear.
Conformal Coating
Material that surrounds and adheres to components and protects them.
Constant Wattage Autotransformer (CWA)
An HID ballast in which the primary and secondary coils are electrically connected.
Core
Component of electromagnetic ballast that is surrounded by the coil and comprised of steel laminations or solid ferrite material.
Core & Coil Ballast
Another term for electromagnetic ballast.
Correlated Color Temperature
A specification of the color appearance of a lamp relating its color to that of a reference source heated to a particular temperature, measured in degrees Kelvin (K).
Crest factor
Ratio of peak lamp current to RMS (average) lamp current.
CSA-E
Marking on ballast that shows compliance with Canadian Ballast Energy Law.
Cycling
See 'Ballast Cycling'.
Chip
A very small square of semi-conducting material. Also known as a die, it is the active light-emitting component of an LED.
Decibel (dB)
Unit of measurement of the volume of sounds.
Design Lumens
The amount of light that the lamp produces after it has operated for approximately 40 percent of its rated life.
Direct Current (DC)
An electrical current flowing steadily in one direction only.
Discharge Lamp
A light producing device that depends on an electric arc, rather than a filament, to create illumination.
DALI (Digitally Addressable Lighting Interface)
An industry standard system protocol that allows components from different manufacturers (ballasts, controls systems, sensors, controllers, switches, etc) to be mixed together seamlessly into complete systems.
DC forward current
Continuous direct current applied which is constant over time.
Die
Chip: heart of the LED.
Diode
A two-electrode device with an anode and a cathode that passes current in only one direction. It may be designed as an electron tube or as a semiconductor device.
Driver
Electronics used to power illumination sources. Ballast.
Electromagnetic Ballast
A ballast that, with the aid of electronic components converts 60 Hz. input voltage and current to high frequency (20 kHz to 60 kHz.) to operate fluorescent and high intensity discharge (HID) lamps.
Electromagnetic Radiation
Radiation originating in a varying electromagnetic field, such as visible light, radio waves, x-rays, and gamma rays.
Electronic Ballast
A ballast that, with the aid of electronic components converts 50 - 60 Hz. input voltage and current to high frequency (> 20,000 Hz.) to operate fluorescent and high-intensity discharge (HID) lamps.
Electromagnetic Interference (EMI)
Electrical interference (noise) generated by electrical and electronic devices. Levels generated by high frequency electronic devices are subject to regulation by the Federal Communications Commission (FCC). Two classifications exist Non-Consumer (also referred to as Class A or Commercial) and Consumer (also referred to as Class B or Residential).
Emitter
The electrode in a transistor where electrons originate
Energy
Work done by an electrical system measured in watts.
ESCO
Energy Saving Service Company
Excessive Neutral Current
Current overload created in the neutral wire of 4-wire, three phase Wye systems by load unbalance or high "third harmonic" current.
Electronic Component
A device or part employed in an electronic circuit to obtain some desired electronic action.
EOL Protection Circuit
For all T5 and smaller lamps, operating parameters within the ballast that, when exceeded, will shutdown the ballast.
ETL
Independent electrical testing laboratory, which performs ballast testing.
FCC (Federal Communications Commission)
The U.S. federal agency that is charged with regulating electrical interference emissions of the electromagnetic spectrum. The regulation entitled, "Part 18" deals with electromagnetic interference (EMI) from all lighting devices operating at frequencies higher than 9 kilohertz (kHz).
Filament
Coated coil of special wire that emits electrons or light when heated.
Filament Voltage
Voltage applied to heat the lamp filament coil. Also called electrode or filament heating.
Filter
Functional grouping that limits interference feedback into the power source and protests internal ballast components.
5-Tap (Five-Tap)
Feature within a ballast which gives you a choice of 5 different input voltages.
Fluorescence
Emission of visible light by the absorption of energy from another source.
Fluorescent Lamp
Gas filled lamp in which light is produced by the interaction of an arc with phosphors lining the lamp's glass tube.
Footcandles (fc)
Measure of light level on a surface that is being illuminated.
Frequency
Rate of alteration in an AC current. Expressed in cycles per second or Hertz (Hz).
Feedback Signal
A feedback signal, or control signal, regulates power through the LED driver to produce various effects in LEDs.
Forward Current
Current through a diode in the direction of its greatest conduction.
Forward Voltage (VF)
The voltage across a diode for a given forward current.
Fundamental Frequency
Lowest frequency in a complex waveform. Also known as first harmonic.
Harmonic Distortion
A measurement of the magnitude of voltage and current harmonics as compared with the amplitude of the fundamental frequency. Harmonic distortion can be generated by a load and fed back into the AC mains, causing distortion of the sinusoidal waveform.
Harmonics
Refers to components of the overall frequency, an integral multiple of the fundamental sinewave frequency.
Hertz (Hz)
Unit used to measure frequency (cycles per second) of alternating current or voltage.
High Intensity Discharge (HID) Lamp
A discharge lamp containing an arc tube in which the active elements within (mercury, sodium, etc.) becomes vaporized (a gaseous state) within the electric arc stream to produce light.
High Frequency Electronic Ballast
In this book, refers to the operation of electronic ballasts as frequencies > 20,000 Hertz (20 kHz).
High Power Factor Ballast (HPF)
A ballast in which the power factor is greater than 0.9 (90%). These ballasts require less line current than normal power factor ballast.
High Pressure Sodium (HPS) Lamp
High Intensity Discharge light source which produce light by an electrical discharge sodium vapor operating at relatively high pressures and temperatures.
High Reactance AutoTransformer Ballast (HX)
HID ballast used when the input voltage does not meet the starting voltage requirement for a lamp. The ballast will transform the input voltage to the required level.
High Flux
LEDs that are approximately 1.0 watts or more and provide a significantly high light intensity. Operate at 350mA.
Hot Restart Time
The time it takes a HID lamp to restart and reach 90% of its light output after going from on to off to on. Typical restart times are 1 to 2 minutes for HPS and 5 to 20 minutes for Metal Halide.
High Light Output
Ballast with a nominal ballast factor of 1.18.
IEEE (Institute of Electrical and Electronics Engineers)
Organization of engineers that establishes standards for electrical and electronics industries.
IES (Illuminating Engineering Society)
Recognized technical authority on the advancement of the art and science of illumination and its dissemination.
Incandescence
Emission of visible light by a heated material
Incandescent Lamp
Lamp in which light is produced by a filament heated by an electric current.
Infrared Radiation
Electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves
Ignitor (Starter)
A device used within the ballast circuit to generate high voltage electrical pulses needed to start high pressure sodium and some metal halide lamps.
Initial Lumens
The measure of the amount of light a lamp produces after it has been operating 100 hours.
Input Voltage
Voltage, provided by a power line or power supply, to the ballast or driver.
Input Watts
Total power input to the ballast that includes lamp watts and ballast losses.
Inrush Current
Initial surge of current when an electrical device is turned on.
Instant Start Ballast
Electromagnetic or electronic lighting circuit without lamp filament heating that produces instant light.
IntelliVolt
Multi-voltage feature of Advance electronic ballasts that allow the ballast to operate from a nominal input voltage range of 120 – 277V at nominal frequencies of 50 or 60 Hz.
IEC (International Electrotechnical Commission)
Organization made up of national committees from over 60 countries that sets international electrical and electronics standards.
InGaN
The preferred LED (Light Emitting Diode) semiconductor technology containing Indium, Gallium, and Nitrogen to produce green, blue and white-colored LED light sources.
Laminations
Layers of steel, making up the ballast "core" that is surrounded by the coils in a core & coil ballast.
Lamp Current
The current delivered to the lamp by the ballast to generate light.
Lamp Current Crest Factor
See "Crest Factor"
Lamp Efficacy
Lamp efficacy is lamp light output divided by lamp power (lumens/watt).
Lamp Filament
See "Filament"
Lamp Flicker
Rapid visible light change occurring in fluorescent lighting systems
Lamp Watts
The power consumed by the lamp to generate light.
Lead-lag Slimline ballast
Ballast that operate fluorescent lamps independently of one another. Can start lamps at 0°F.
Light
Radiant energy which can be sensed or seen by the human eye. Visible light is measured in lumens.
Light Emitting Diodes (LED)
A solid-state semiconductor device that converts electrical energy directly into light. On its most basic level, the semiconductor is comprised of two regions. The p-region contains positive electrical charges while the n-region contains negative electrical charges. When voltage is applied and current begins to flow, the electrons move across the n region into the p region. The process of an electron moving through the p-n junction releases energy. The dispersion of this energy produces photons with visible wavelengths.
Life (Average Rated) or Lamp Life
The median time it takes for a lamp to burn out.
Line-interrupt
A brief stoppage in the flow of current supplied by the electrical distribution system.
Low Flux
LEDs that are typically .1 to .4 watts each, and are arranged in clusters or arrays to create a collective light source. These systems operate a 12vdc or 24 vdc.
Low Power Factor Ballast (LPF)
Ballast with a power factor of 0.79 or less - also called normal power factor (NPF) ballast. LPF ballast requires about twice the line current of HPF ballast so fewer LPF ballasts can be installed on a circuit, which increases installation cost.
Lumen Depreciation
The decrease in lumen output of a light source over time. Also called Lumen Maintenance.
Lumen Maintenance
The rate at which light output declines over time.
Lumens
Measurement of light emitted by a lighted lamp.
Lumens per watt
Units of light produced per unit of power.
Luminaire
A complete lighting fixture consisting of a lamp (or lamps), ballast(or ballasts) as required together with the parts designed to distribute the light, position and protect the lamp, and connect them to the incoming power.
Luminous Efficacy
The light output of a light source divided by the total power input to that source. Expressed in lumens per watt.
Lamp
The lighting industry term for light bulb. It refers to the complete assembly including the internal parts as well as the outer bulb or tube and base(s).
LED Driver
See 'Driver'.
Line Current
See 'Ampere'.
Low Power Factor
See 'Normal Power Factor'.
Low Voltage Control
DC voltage used for signaling purposes
Low Watt
Ballast with a nominal ballast factor of 0.78 or less.
Mean Lumens
Average light produced when lamp has been operating about 40 percent of rated life.
Mercury Lamp
A High Intensity Discharge (HID) light source in which the light is produced by radiation from mercury, plus halides of metals such as sodium, scandium, indium and dysprosium.
National Electric Code (NEC)
A nationally accepted electrical installation code developed by the National Fire Protection Association to reduce the risk of fire.
National Energy Standards for Fluorescent Ballasts
A federal law enacted in 1988 that sets energy standards for ballasts consistent throughout the United States.
Non-PCB Capacitor
Capacitor used in ballasts to help provide power factor correction.
Normal Power Factor
Ballast in which the power factor is less than 0.80 (80%). These ballasts require about twice the line current of high power factor ballasts.
National Electrical Manufacturers Association (NEMA)
U.S. based association that sets many common standards used in electrical products
NOM (Normas Oficial Mexicana)
Laboratory that sets safety standards for building materials, electrical appliances and other products for Mexico.
Normal Light Output
Ballast with a nominal ballast factor of 0.88 for most T8 ballasts, and 1.00 for most T5 and dimming ballasts.
Open Circuit Voltage [OCV]
Voltage, as measured at the lamp socket (HID or CFL) or across the lamp holders (fluorescent) when the lamp is not present, generated by the ballast needed to start a lamp when power is turned on.
Operating Position or Burn Position
The orientation of an HID lamp in a lighting fixture such as base up, base down, horizontal, or universal.
Parallel Circuit
Ballast circuit in which the lamps connected to one ballast operate independently of one another – if one lamp fails, the rest remain lit.
PCB (Polychlorinated Biphenyls)
Chemical pollutant used in capacitors outlawed by the EPA in 1978. Ballast industry transitioned to non-PCB capacitors during 1979. See the FAQs on our 'Environmental' page for more details on Advance ballasts and PCBs.
Phosphor
Material lining the interior of a fluorescent lamp, which emits light.
Potting
See "Asphalt silica sand mixture".
Power
The amount of energy consumed or needed by a device (ballast, lamp, or ballast plus lamp) to perform its function. Power is measured in watts.
Power Factor (PF)
A measurement of how efficiently an electrical device uses power supplied by the power line. PF = Watts / (Volts x Amps).
Power Factor Corrected Ballast (PFC)
Ballast with a power factor from 0.80 to 0.89
Preheat Ballast
Electromagnetic ballast that requires separate starter in order to ignite the lamp.
Preheat Lamp
A fluorescent lamp in which the filaments must be heated before the lamp ignites.
Programmed Start Ballast
An electronic lighting circuit similar to rapid start that provides precise heating of the lamp filaments and tightly controlling the preheat duration before applying starting voltage to ignite the lamp.
Packaged LED
Consists of the die, a lead frame, which houses the die, the encapsulation epoxy that protectively surrounds the die, and also disperses the light.
Parallel (LED)
Electrical condition where LEDs operate under the same voltage being provided by a driver.
Potting
Compound used to completely surround and cover components of some magnetic and electronic ballasts in order to protect components, dampen sound, and dissipate heat.
Powerline Control
Method of dimming control where the phase of the sine wave is ?chopped' to dim the lamps.
Probe Start
Method of starting mercury vapor and specific metal halide lamps in which an additional electrode at one end of the arc tube assists in lamp starting.
Pulse Start
Method of starting high pressure sodium and specific metal halide lamps in which a high voltage starting pulse starts the lamps.
Quality Assurance
Term used in modern industry to describe procedures applied to design and manufacturing operations in order to obtain products of the highest possible quality, formerly called "Quality Control".
Quadri-Volt (Quad-Tap)
Feature within a ballast which gives you a choice of 4 different input voltages.
Rapid Start Ballast
Electromagnetic or electronic ballast that provides both filament heating and starting voltage to the lamp at the same time in order to ignite the lamp.
Rapid Start Lamp
Fluorescent lamp that requires filament heating before igniting and producing light.
Reference Ballast (standard reactor)
Laboratory device used to provide ANSI specified measurements of initial and mean lamp lumens.
RFI - (Radio Frequency Interference)
Form of electromagnetic interference.
Rank
See 'Bin'.
Regulation, Lamp Wattage
The measure of the ability of a ballast or ballast circuit type to control (regulate) a lamp's operating wattage as the input voltage varies from nominal. It is the ratio of the percent change in line voltage (input voltage) and the resultant percent change in lamp wattage.
Reverse Current
Current flowing through a diode in the direction opposite to the direction of maximum conduction.
Reverse Voltage
Volatge across the diode for a given reverse current.
Series Circuit
Ballast circuit in which the lamps connected to one ballast operate as a group. If one lamp fails or is removed, then all lamps in the circuit turn off.
Series-Parallel Circuit
Ballast circuit in which the lamps connected to one ballast operate both as a group and independently. If one lamp fails or is removed in the series connected section, then all lamps in that section will turn off, but the lamps in the parallel circuit remain on.
Series-Sequence Slimline Ballast
Electromagnetic ballast that operates slimline lamps in series, with the lamps starting in sequence.
Sine Wave
A mathematical function used to represent AC voltage and current.
Slimline Instant Start Circuit
Circuit that produces light instantly in slimline, instant start fluorescent lamps.
Slimline Lamp
Fluorescent lamp, which has single pin contacts, that requires no filament heating to ignite.
Standard Reactor
See reference ballast.
Starting Temperature
The minimum ambient temperature at which the lamp will start. Light output may be affected due to lamp characteristics.
Striation
Spiraling or swirling of fluorescent lamps at initial turn on or energy-saving lamps at low temperature or low current.
System efficacy
Overall efficiency of the lamp/ballast system. System efficacy = total lamp lumens / system wattage.
Series (LED)
Electrical condition where LEDS operate under the same current being provided by a driver.
Series-Sequence Slimline Ballast
Ballasts that operate with lamps starting in sequence.
Sound Rating
Classification given to a ballast based upon ballast noise.
T12, T10, T8, T5
Industry standard naming for a fluorescent lamp. (T= Tubular and the numbers that follow represent the diameter in 1/8 inch increments.)
Thermal Protector
A self resetting switch that disconnects power to the ballast if internal temperatures rise above the trip point- typically 105C.
Third Harmonic
Third multiple of the fundamental frequency that will add in the neutral wire of a three phase, 4 wire, Wye system and will cause over heating of the neutral wire should it exceed 33 1/3 percent.
Three Phase Current
Current delivered through three wires with each wire serving as the return for the other two.
Total Harmonic Current (THC)
The combined effect of all of the harmonic distortion on the AC waveform produced by a ballast or other device. Excessive levels of THC can create large currents on the neutral line of a 3 phase 4 wire wye power system. See Harmonic Distortion.
Three-Phase 4-wire Wye
Most popular electrical wiring system for building wiring in use today.
Total Harmonic Distortion
Total Harmonic Current (THC) expressed as a percentage.
Transients
High voltage and resultant high current surges through an electrical system caused by lightning strikes to nearby transformers, overhead lines or the ground. May also be caused by switching of large motors or other electrical loads, as well as by short circuits or utility system switching. Can lead to premature failure of ballasts or other electrical devices.
Trigger Start Ballast
Electromagnetic ballast that starts and operates preheat lamps similar to a Rapid Start lamp. No separate starter is needed to ignite the lamp.
UL (Underwriters' Laboratories, Inc.)
A not for profit organization in the US that generates product performance and safety standards for electrical equipment, building materials, and other products. End use products such as lighting fixtures, fully encased ballasts, and home appliances are examples of UL Listed products and bear the UL logo. Components such as HID open core & coil ballasts, electrical insulating materials are UL Component Recognized products and bear the UL Component Recognition logo.
UR (UL Recognized)
A part or subassembly covered under UL's Recognition Service and intended for factory installation in UL certified products. They are intended for use as components of complete equipment submitted for investigation by UL.
Voltage (V)
A measurement of the electromotive force (electrical pressure) in an electrical circuit or device expressed in volts. Voltage can be thought of as being analogous to the pressure in a plumbing system.
Voltage Sag
Drop in voltage levels of electrical distribution system that interferes with the operation of electrical and electronic equipment. Commonly called "Brownout". Results when demand for electricity exceeds capacity of the distribution system.
