lighting terms
- 2-TAP-HID ballast that operates at two input voltages: 120, 277.
- 4-Tap-HID ballast that operates at four input voltages: 120, 208, 240, 277.
- 5-Tap-HID ballast that operates at five input voltages: 120, 208, 240, 277, 480.
- Accent Lighting-Localized and directional lighting used to highlight, focus attention, or dramatize a room or outdoor space. This is also known to highlight the texture of a wall, drapery or outside landscaping. Accent lighting requires at least three times as much light on the focal point as the general lighting around it.
- Alternating Current-Flow of electricity which cycles or alternates direction many times per second. The number of cycles is referred to as frequency. Most common frequency used in this country is 60 Hertz, which is the cycles per second.
- Amperes (amps)-The unit of measurement of an electrical current.
- Architectural Lighting-This generally refers to built-in fixtures, such as downlighting, valance lighting or luminous ceiling. Some also include functional lighting, such as track or simple fluorescent lighting.
- Average Rated Life-An average rating, in hours, indicating 50% of a large group of lamps have failed, when operated at nominal lamp voltage and current. Manufacturers use 3 hours per start for fluorescent lamps and 10 hours per start for HID lamps when performing lamp life testing procedures. Every lamp type has a unique mortality curve that depicts its average rated life.
- Ballast-Electrical or electronic component required for fluorescent and HID lamps. Ballasts provide enough voltage to start the lamp and then limit the current for continuing operation.
- Base-The end of the lamp that inserts into a lamp socket. The end or ends of a lamp that makes electrical and mounting connections.
- Built-in Lighting-Built-in lighting generally refers to lighting equipment mounted into coves and cornices, behind valances, or integrated into furniture and bookcases.
- Bulb-This is the term used on a daily basis for an incandescent lamp. Also refers to the outer glass envelope of the lamp.
- Cable-Multiple wires arranged in a common covering of insulating plastic or other materials, used as an electrical conductor.
- Circuit-Wiring path for electricity, including conductors, load and circuit protection
- Circuit Breaker-Resettable safety device to prevent current flow or prevent excess current flow.
- Color Rendering Index (CRI)-A measurement to rate a lamp’s ability to render an object’s color on a scale of 0-100, the higher the CRI, the more true to life colors appear, as they would in natural daylight.
- Color Temperature-The actual color of a light source, also referred to as Correlated Color Temperature (CCT), measured in degrees Kelvin (K). Typical color temperature is:
2700K Incandescent /Fluorescent – Warm White
3000K Halogen/Fluorescent – Soft White
3500K Fluorescent – White
4100K Fluorescent – Cool White
5000K Fluorescent – Natural White
6500K Fluorescent – Daylight
- Compact Fluorescent Lamp-A small, fluorescent lamp, often used as an alternative to incandescent lighting, that utilizes small diameter tubes that are bent so that they begin and end in a single base. The lamp life is about 10 times longer than incandescent lamps and is 3-4 times more efficacious
- Core and Coil Ballast-Another term for an electromagnetic ballast.
- Cove Lighting-Light built into a cove, a shelf or ledge at the upper part of a wall, to illuminate the ceiling. Typically fluorescent, cold cathode or low voltage strip.
- Damp Location-UL listing for fixtures used in moist unexposed area, such as a bathroom or porch area.
- Diffuser-Light control device that spreads light by scattering it. Opal glass and plastic, etched glass, fabric and paper shades act as diffusers.
- Dimmer-Control that varies the output of the light source by reducing the voltage or current to the lamp.
- Direct Lighting-Lighting that casts all, or at least 90%, of its light downward. The term can also refer to the distribution of light or the fixtures that produce this type of lighting. With intense beams, direct lighting is very dramatic, rendering forms and textures well. Typical fixtures include recessed lights, track lights, some pendant lights and task lights.
- Electromagnetic Ballast-A low-frequency ballast that operates through the use of current carrying coils assembled on a magnetic core.
- Electronic Ballast-A ballast that uses semiconductor components to increase the frequency of fluorescent lamp operation (typically in the 20-40 kHz range). Smaller inductive components provide the lamp current control. Fluorescent system efficiency is increased due to high frequency lap operation. Results are increased lamp efficacy, reduced ballast losses and lighter, smaller ballasts compared to electromagnetic ballasts. Electronic ballasts may also be used with HID (high intensity discharge) lamps.
- Energy-A measure of work done by an electrical system over a given period of time; measured in kilowatt-hours (kWh).
- Energy Policy Act (EPACT)-Energy legislation originally passed by Congress in 1992, and updated periodically, mandating labeling and minimum energy efficiency requirements for many commonly used incandescent and fluorescent lamps.
- Energy Survey-Systematic cost comparison of an existing system to a proposed system, accounting for electrical, material, maintenance and labor costs.
- Extended Life Lamp-Incandescent lamp with 2500+ hours rated average life and reduced output; uses a stronger filament.
- Filament-The tightly coiled tungsten wire of an incandescent lamp; glows to produce light when electricity flows through it.
- Fill Gas-In incandescent lamps, usually argon or krypton with trace nitrogen. In fluorescent lamps may be argon. Halogen is used in halogen incandescent lamps.
- Floodlight-A reflector lamp designed to produce a broad, relatively diffused beam of light.
- Fluorescent Lamps-Lamps which operate by creating an electric arc inside a gas-filled tube. The color of light is determined by the type of phosphor coating used in the lamp.
- Footcandles-Unit of illuminance (light falling on a surface). One lumen falling on one square foot equals one-foot candle. Also, a measurement of the amount of light reaching a subject.
- Frequency-A measurement of the number of cycles per second; the SI base unit is Hertz (Hz).
- G Lamp-Globe-shaped incandescent, generally for exposed use.
- General Lighting-Also known as ambient lighting, general lighting provides an area with overall, non-specific illumination. General lighting radiates a comfortable level of brightness, enabling one to see and walk about safely. It can be accomplished with chandeliers, ceiling or wall-mounted fixtures, recessed or track lighting or with outdoor fixtures. A basic form of lighting that replaces sunlight.
- Glare-Bright lighting that causes discomfort and impairs good visibility. Possible causes may be light sources that are too bright for the application, or fixtures that may not conceal bulbs sufficiently, among many others.
- Grazing Light-Directional light at an acute angle, which emphasized texture. The sources of grazing light must be close to the surface.
- Grounding-Connecting electrical components to earth for safety.
- Halogen Lamp-Incandescent lamp with halogen gas fill and a quartz glass capsule. The quartz capsule requires a separate glass shield or enclosure. Due to the halogen cycle, halogen lamps operate at higher internal temperatures, producing more lumens per watt and brighter light than ordinary incandescent; lamp life is also extended. Halogen lamps include A, MB, T, PAR and MR types.
- Heat Ratings-Like recessed downlights, surface mounted fixtures must pass heat tests to assure they do not affect combustible ceiling materials. This limits the maximum wattage in these fixtures, and sometimes necessitates the installation of high-temperature wiring. Always follow the labeled lamping; never use higher wattages or different lamps.
- High Intensity Discharge (HID) Lamp-Metal Halide, High Pressure Sodium, and Mercury Vapor lamp types.
- High Output Fluorescent (HO)-Fluorescent lamps designed to be used with an 800 milliampere ballast. Able to operate at low temperatures (down to zero degrees Fahrenheit) and still produce high light levels.
- High Pressure Sodium (HPS) Lamp-High intensity discharge light sources which produce light by an electrical discharge through sodium vapor operating at relatively high pressures and temperatures.
- Incandescence-Light produced by heating material so it glows. Incandescent filament lamps, candle flames and glowing coals are all examples.
- Incandescent Lamp-Produces light with a wire filament, which create light as it is heated by electric current.
- Inches to Millimeters Conversion-To calculate the metric equivalent of inches in millimeters (mm), multiply inches by 25.4.
- Indirect Lighting-Lighting that directs all or most light upward or general illumination; comfortable illumination with few shadows. Typical fixtures include uplight cans, fluorescent lighting aimed up, track lights aimed up and torchieres.
- Induction Lighting-A means of lighting, which uses RF induction of radio waves or microwaves to produce luminescence. Induction lamps have no electrodes inside the chamber and generally, therefore, have no longer life than standard incandescent lamps.
- Input Voltage-Voltage required from a power supply for proper operation of a ballast.
- Jack-Plug-in stem used in low voltage fixtures.
- Junction Box-Enclosure that protects spliced wire and supports surface fixtures, such as wall fixtures or ceiling fans. Also called an outlet box.
- Kelvin-Scientific unit of temperature. Color temperature is measured on the Kelvin scale.
- Kilowatt Hour-KWH. A unit of measurement for electrical energy. One kilowatt hour equals 1000 watts of energy used for one hour.
- Lamp-Lighting industry tern used for a light bulb
- Lamp Dimensions-Bulb designations consist of a letter(s) to indicate shape and a number to indicate the diameter in eights of an inch.
- Lamp Holder-Socket on a cable, which holds the lamp in place and connects it to the electrical source.
- Lamping-Equipping a fixture with a lamp.
- LED-Light Emitting Diode. A small, solid state device used to indicate dimmer or control status; also used in signs and control units.
- Lighting Controls-Devices which give you flexibility, decorative effects and multiple uses from your lighting sources. Today’s sophisticated dimming systems enable you to lower the light level to conserve energy and increase bulb life; vary the mood of a room; alter light source intensity; create lighting scene in each room. Types of controls include integrated dimming systems, touch dimmers, slide dimmers and rotary dimmers.
- Light Distribution-Pattern of light produced by a fixture, or created in a room.
- Light Sources-The performance of any light fixture depends on the light source, or bulb, that’s used. Different sources produce different effects.
- Low Voltage Fixtures-Task, linear or accent lighting products for low voltage lamps. A transformer is required for these fixtures and may be integrated, local or remote.
- Low Voltage Lamps-Incandescent lamps that operate at 6, 12, or 24 volts. Low voltage lamps require a stepdown transformer to reduce the voltage from the normal household 120 volts.
- Low Voltage Lighting System-A type of lighting that operates on 12-volt or 24-volt current rather than the standard 120 volts. Power is supplied by a transformer, which is itself connected to 120-volt power.
- Lumens-The amount of light that a bulb produces. Unit of output; technically “Luminous flux.”
- Luminaire-
A complete lighting unit including lamps, housing, lens and ballast if required. All the necessary components to make what we commonly refer to as a “fixture”.
- Metal Halide Lamp-A high intensity light source in which the light is produced by the radiation from mercury, plus halides or metals such as sodium, scandium, indium, and dysprosium. Some lamp types may also utilize phosphor coatings.
- Motion Detector-Control that uses passive infrared or ultrasonic detection to sense whether someone is present or not, and to turn a light on or off appropriately. Commonly used in outdoor flood or spot fixtures. “Automatic On” sensors turn lights on when presence; “Manual On” sensors require you to press a switch. Both types turn lights off automatically when they no longer sense a presence.
- MR Lamp-Multi-facet reflector lamp, of which the most popular is MR16. MR lamps surround a halogen capsule with a computer-designed glass, or metal reflector with many surfaces or facets. These compact lamps require a glass cover, either integral or with the fixture.
- Highbay & Lowbay Lights
- Multi-Volt-A fluorescent electronic ballast that has a universal input voltage; typically these ballasts have an acceptable input voltage range 108V to 305V.
- National Electrical Code-Sets out standards for wiring and electrical devices. The NEC requirements are widely followed by local jurisdictions.
- NEMA-National Electrical Manufacturers Association. Includes lamp, electrical device and larger fixture manufacturers. NEMA develops consensus ratings and designations for various products.
- Nominal Length-A measurement for Fluorescent lamp length based on the length of the lamp plus an allowance for the luminaire’s lamp holders.
- Nominal Watts-The power rating of lamps, as published by lamp manufacturers
- Operating Position-Lamps may be operated in any position unless otherwise noted.
- Outdoor Lighting-Any hard wired, low-voltage or solar powered lighting system that is used in an exterior space. Outdoor lighting can enhance the beauty of your business, making it safer and more secure. Outdoor lighting typically is an investment that pays off in the value it adds to a business.
- Outlet Box-Also known as a junction box, is an enclosure that protects spliced wires and supports surface fixtures.
- Over Voltage-Incandescent lamps experience shortened lamp life when operated above their rated voltage.
- Photocell-Light-sensitive device used to operate fixtures according to available daylight. They are used in solar lighting and to turn outdoor or security lights on and off at dusk and dawn.
- Power Feed-The connection point that brings electricity to track and other lighting systems. Power feed may be at the end, floating or at a wiring intersection.
- Probe Start-A starting method for HID lamps that involves the use of a probe to start the lamp. A large surge of voltage is applied to the probe in order to assist in starting the lamp.
- Programmed Start-A fluorescent lap-ballast circuit that uses a custom integrated circuit (IC), which monitors lamp and ballast conditions to ensure optimal system lighting performance. PS ballasts heat the lamp cathodes to 700 degrees Celsius prior to ignition. This puts the least amount of stress on the lamp electrodes, resulting in maximum lamp life regardless of the number of lamp starts. Programmed-start ballasts are typically wired in series.
- Pulse Start-A fluorescent lap-ballast circuit that is designed with an ignitor to ignite the arc tube. Due to this, bulbs have no need for the started electrode. Pulse start lamps are typically more efficient than standard counterparts.
- Quartz Lamp-Also known as quartz halogen, this term derives from the quartz glass that encloses the filament and halogen gas. Quartz glass can withstand the high pressure of the halogen lamp, but it transmits more UV radiation than ordinary hard glass. Touching the quartz glass with bare hands leaves an oily residue that greatly reduces lamp life.
- Rapid Start-A fluorescent lamp-ballast circuit which utilizes continuous cathode heating, while the system is energized, to start and maintain lamp light output at efficient levels. Rapid start ballasts may be either electromagnetic, electronic or of hybrid designs. Full-range fluorescent lamp dimming is only possible with rapid start systems.
- Rated Lamp Life-The point in hours where 50% of a lamp type initially started will still be functioning
- Reflector-A piece of material with a reflective surface that directs light in a desired direction. Reflectors are frequently specular, but may also be glossy, diffuse, or matte.
- Re-lamping-A project where the existing lighting fixtures in a business setting are cleaned and new lamps installed.
- Retrofit-Upgrading a fixture, room or building by installing new lighting fixtures, parts or equipment.
- Romex-A cable comprised of flexible plastic sheathing inside of which are two or more insulated wires for carrying electricity
- Silhouetting-Accent lighting technique that creates a dramatic outline by back lighting. Also used in landscape lighting
- Soffit-In architecture, the underside of an overhead component, such as an arch, cornice, beam or balcony. Often used to describe an area of the ceiling that drops below the primary surface.
- Solid State-Electronics that use semi-conductor chips and circuitry
- Specialty Lighting-A term referring to everything from line and low voltage strip lights to special display or controlled lighting as seen in retail and commercial applications
- Specular Finish-Highly polished and mirror-like. Semi-specular finish is generally bright, but without a well-defined mirror image.
- Spiral Lamp-A helical-shaped long life compact fluorescent lamp.
- Stainless Steel-Stainless steel resists corrosion and has a rich, deep luster. It is particularly used in bathroom and kitchen settings for a clean, contemporary look.
- Starter (Ignitor)-A device used in conjunction with a ballast to start preheat fluorescent lamps.
- Step Lights-Step Lights are recessed into walls and stairs so they illuminate the treads of stairs or pathways. An eye shield is often used to block direct view of the light source
- Switch Leg-Wiring that connects the switch or dimmer output to the fixture or load being controlled
- T-Lamp-Tubular Lamp; may be incandescent, halogen or fluorescent.
- Task Lighting-Lighting directed to a specific area or surface that provides illumination for visual tasks. It can be provided by recessed and track lighting, portable lighting or pendant lamps. Task lighting should be free of distracting glare and should be bright enough to prevent eyestrain.
- Thermal Protector-A device used in a ballast to detect when the maximum temperature of the ballast has been exceeded and when to remove input power. Thermally protected ballasts that meet UL certifications are classified as “Class P”.
- Timer-Device that turns lights on and off at pre-programmed times.
- Toggle-Lever used for control as in the common toggle switch or toggle dimmer
- Torchiere-Indirect floor lamp that sends all, or most, of its light upward.
- Transformer-A device used to raise (step up) or lower (step down) the electric voltage. For example, many halogen ceiling fixtures require a transformer to function properly. Step down transformers reduce voltage (120 volts) to low voltage used in accent and landscape lighting. Larger transformers reduce high voltage used for efficient power distribution to safe and flexible voltage. Input voltage is on the primary tap; output voltage on the secondary tap.
- Trim-Sometimes the edge or visible part of a recessed downlight; as in “white trim”. Sometimes the finishing section of the recessed fixture.
- Troffer-Recessed fluorescent fixture for use in a suspended ceiling; derived from the words “trough” and “coffer”.
- Tungsten-Halogen Lamp-A gas filled tungsten incandescent lamp containing a certain amount of halogens that intensifies the light source. More commonly referred to as “Halogen” lighting.
- Undercabinet Fixtures-Fixtures which are placed under a cabinet or room recess to provide task and accent lighting. They can light a countertop with task lighting. In a display cabinet they can be used to illuminate a prized collection. They include slim, energy-efficient fluorescents, miniature track lighting and strips of low-voltage mini-lights.
- UL-Underwriters Laboratory.-Commonly referred to as “UL”. An independent organization whose responsibilities include rigorous testing of electrical products. When products pass these tests, they can be labeled and advertised as “UL Listed”. UL tests for product safety only.
- Ultraviolet Light (UV)-Light that is shorter in wavelength and higher in frequency than visible violet light.
- Valance Lighting-A fixture installed behind a horizontal shielding over a window or along a wall. Light is distributed up and down, usually from a fluorescent source.
- Very High Output (VHO)-Fluorescent lamps designed to be used with a 1500 milliampere ballast.
- Volt-Unit of electromotive force (emf). The difference in electrical potential that will cause a current of one ampere to flow through a resistance of one ohm.
- Voltage Drop-Difference in voltage along a circuit. Voltage drop becomes a problem with low voltage wiring and small cable, reducing the intensity of the lights at the far end of the cable.
- Voltage Rating-The recommended operating voltage for a lamp.
- Watt-A unit of electrical power
- Wattage-The amount of electricity consumed by a bulb.
- Wire Nut-Also called a solderless connector. Small plastic devices that can be fastened over the bare joined ends of several wires to protect and insulate the connection.
- Xenon-A heavy, colorless, and relatively inert gaseous element that occurs in air as about one part in 20 million by volume and is used especially in thyratrons and specialized flashtubes.
