Lighting Terminology for Dummies

A

 

Accent Lighting:  Focusing light on a particular space or object.   Intended to create visual interest in an area or object.   

 

Alternating Current (AC):  Electric Current in which the flow of electric charge reverses direction at regular intervals.  

 

Amps (A): Standard Unit of  Measurement of electric current.

 

B

 

Ballast: A device used to regulate current and voltage to start and operate a lamp.   Ballasts are used with HID and Fluorescent light sources.

Ballast Factor: Indicates the percentage of rated light output and power that can be expected of a lamp.

 

C

 

Candela (cd):  Measurement of luminous intensity of a source in a given direction.

 

Center Beam Candle Power (CBCP): Luminous intensity at the center of a light source beam

 

Color Rendering Index (CRI): A Measure of a light sources ability to show colors accurately.  The Scale is from 1 to 100.  The sun is considered 100.

 

Color Temperature: Correlated Color Temperature (CCT).  A measurement of hue of the light produced by a source.  

 

D

 

Diffuser: A device used to alter light by scattering it in order to create softer light with minimal glare

 

Dimmer: A device used to control the light output of a light source.

 

Direct Current: Electrical current that flows in only one direction without cycling.  DC current is most commonly used with batteries and PV cells.

 

Direct Replacement: it's as simple as Plug-N-Play! Direct replacement LED lamps from OEO screw into your existing fixture without the need to rewire or upgrade while helping to save you up to 84% on energy costs.

 

Driver: Electrical or electronic circuit that controls other components.  In LED Lighting Systems, the driver regulates the power to the LEDs.

 

E

 

Efficacy: Lumens per Watt of a light source

 

Electromagnetic Interference: Disruption of an electronic device by an external source by electromagnetic induction, electrostatic coupling, or conduction.

 

Electronic Ballast: Ballast composed of electronic components instead of the core-and-coil transformer.  Electronic ballasts do not experience as much power loss as magnetic ballast.

 

F

 

Fluorescent Lamp: Low Pressure Mercury-Vapor-Gas-Discharge Lamp that uses fluorescence to produce visible light.   Fluorescent lamps require a ballast for current and voltage regulation.

 

G

 

Glare: Glare is a visual sensation caused by excessive brightness.  It can be discomforting or disabling.  

 

H

 

Halogen Lamp: Halogen Lamp is a type of incandescent lamp that incorporates halogen in order to increase the average life and light output of the light source.

 

Heat Sink: Device incorporated in LED Lighting Systems to disperse heat away from the LED diode.   

 

Hertz (Hz): The standard unit of measurement for frequency.  One Hz equals one cycle per second.

 

High Bay: Type of Light Fixture typically used for commercial and industrial applications with high ceilings (>20 ft).

 

High Intensity Discharge Lamp: HID Lamps.   Family of electrical gas-discharge lamps that produce light by means of electrical arc.  

 

High Pressure Sodium Lamp (HPS): Type of High Intensity Discharge Lamp.  Frequently used in street and outdoor lighting applications.  

 

I

 

Illuminance: Measured in Lux or Footcandles,  Illuminance is the total luminous flux on a surface.  

 

Initial Lumens: Total luminous flux of a light source at the beginning of its life.

 

K

 

Kelvin Temperature (K): Unit of measurement of the Correlated Color Temperature of a light source.

 

L

 

Lamp Base: The Portion of a lamp that connects to the luminaire socket and power.

 

Light Emitting Diode (LED): A semiconductor device that emits light as electrical current passes through it.  Light-emitting diodes are more efficient than other light sources and offer exceptionally long life

 

Lumen: Standard unit of measurement of luminous flux.  Used to measure the total quantity of visible light emitted by a light source.

 

Luminaire: Light Fixture.  A complete unit consisting of lamp, ballast, reflectors, lens, and other parts.   

 

M

 

Magnetic Ballast: Often Called "Core-and-Coil" ballast. Magnetic ballasts contain a magnetic core with copper windings.  Magnetic ballast typically have greater power losses than electronic ballasts.

 

Mean Lumens: Average luminous flux produced by a light source over the duration of its rated life.

 

Metal Halide Lamp: High intensity discharge lamp that generates light by passing an electric arc through a mixture of mercury and metal halide gases.

 

N

 

O

 

P

 

Photocell: Light Control that turns a light source on/off depending on daylight

 

Power Factor: The ratio of real to apparent power supplied to a circuit.   Power factor can range from 0 to 1.   

 

Q

 

R

 

Reflection: Light bouncing off a Medium.

 

Refraction: Bending of light as it passes through a medium.  The bending in light is a result of the change of speed as it passes from one medium to the next.

 

Restrike Time: The time it takes for a lamp to reach full brightness after being turned off and back on.

 

Retrofit:  Upgrading old and inefficient technology with new equipment to improve the  efficiency of a light system

 

S

 

T

 

U

 

V

 

Voltage: Potential Difference in charge between two points in an electrical field.  Measured in Volts (V).

 

Voltage Drop: Loss of voltage caused by resistance.  Voltage Drops can be created by too long or too think wire.   

 

W

 

Wall Pack: The most widely used commercial outdoor lighting fixtures used today. Wall packs are powerful light fixtures that are installed in outdoor locations of commercial buildings.

 

Watt: Standard unit of measurement for power.   One Watt Equals one Volt-Amp.  

 

X

 

Y

 

Z