AC: Alternating current: An electrical current that reverses its direction at regular intervals

Accent lighting: Lighting that focuses on a specific object or architectural feature

Ambient lighting:General lighting in a room

Amp: Measure of rate of electrical flow in a circuit

Backplate: Flat plate behind wall sconce to cover electrical box

Baffle:Waffle device used to reduce glare

Ballast: Device used to control the current and prevent overheating in a discharge lamp

Barn doors: Hinged shutters used to precisely shape the beam of a lamp

Bobeche: Decorative crystal, metal, wood, etc. “bowl” used on chandeliers and sconces, often pierced to hold crystals (originally used to catch wax dripping from candles)

Breaker box: Metal box with fuses or circuit breakers that breaks down electrical service into smaller circuits

Bus bar: Fuse box, breaker box

BX or flexible metal conduit: Bendable tubing that holds electrical lines

Candlecover: Plastic, metal, or cardboard sleeve that simulates the look of a wax candle (to conceal a socket)

Candela: Unit of light intensity (SI), roughly equivalent to 12.57 lumens

Candlepower: Luminous intensity of a light source measured in candela

Canopy: Decorative plate that goes flush to the ceiling on a chandelier or ceiling light that conceals electrical box

Chimney: Open-ended glass surround used on an oil lamp to hold lampshade

Circuit: Path of electrical flow (wiring)

Circuit breaker: Switch that interrupts electricity in case of a short or overload

Check ring: Metal disk that holds candlecover or neck on a light fixture

Clip adapter: Metal bulb clip that attaches to a lampshade converting it to a shade that clips onto the bulb

Collar: Threaded ring that holds the canopy to the ceiling on a chandelier

Color rendition index: A measure of the effect of a particular kind of light bulb on a colored surface (the larger the number, the truer to the color in real sunlight; measured between 1 and 100)

Common: Dark-colored screw on an electrical switch

Conductor: Wire that carries electricity

Conduit: Rigid or flexible tubing that holds electrical wires inside

Contacts: Connection point for electrical wires

Continuity Tester: Test device for electrical circuit

Cord switch: On-off switch for a portable lamp that attaches along the cord

Current: Flow of electricity through a wire, measured in amps

DC (direct current): Electrical current that flows in only one direction, not a complete circuit

Diffuser: Translucent “shield” designed to reduce glare and filter light more evenly

Dimmer: Switch that allows you to vary the intensity of a light fixture

Discharge lamp: Light bulb which incorporates an electronic discharge through a gas or vapor

Duplex receptacle: Outlet with 2 plug-in connections

Efficacy: Lumens per watt measure of the efficiency of a light source

Electrical box: Box in the wall where electrical connections are made to fixtures and that supports fixtures

Electric meter: device that measures amount of electricity consumed

Electronic transformer:

Faceplate: Switch box or outlet cover plate

Filament: Thin tungsten wire that emits light when heated by an electrical current

Finial: Decorative item with threaded base used to secure a lampshade to a harp and “finish” the look of a table or floor lamp

Fish tape: Extending metal tape with a hook on the end used to pull wires through a wall

Fitter: Decorative rim that holds glass shades on place on a light fixture

Fixture: Any decorative electrical item that permanently affixes to a wall or ceiling

Flush mount: Light fixture that hangs flush on the ceiling

Foot switch: Device for turning a floor lamp on and off that sits on the floor and is joined to the cord

Framing projector: device that allows you to accurately control the size of the light beam

Fuse: Screw-in, plug-in, or snap-in device that interrupts electricity in case of a short or overload

Ganging: 2 or more electrical lines ending in the same switch box or receptacle

Ground wire: Wire (that carries no current) that runs from the fixture to metal attached to nonmetal material to ground the current in case of a short (Ground wire is usually bare copper or green).

GFI: Ground-fault interrupter: A sensing device that shuts down the electricity in the case of a shock hazard

Harp: Metal “U” that supports lampshade over bulb and lamp base

Harp holder: Metal “U” that connects harp to lamp base

Hot wire (live wire): Wire that carries the current to a receptacle and fixture (usually black)

Hurricane: Decorative glass surround for candle-like sockets

Illuminance: Amount of light that falls on a surface (measured in lumens per square foot)

Indirect lighting: Lighting that is reflected off a wall, ceiling, shade, etc.

Insulation: Nonconductive coating that protects electrical wires

Junction box: Connection point for wires from fixture to fixture and switch box to fixture

Kelvin (color temperature): Measure of redness or blueness of a light source (the higher the number, the warmer the color)

Kilowatt: 1000 watts (measure of electrical consumption)

Knockouts: Tabs that can be removed from electrical box or fixture to make wiring connections

Lamp: Technical name for light bulb

Loop: Threaded U-joint that attaches chain to the canopy on a chandelier

Locknut: Threaded nut used to tighten parts inside a light fixture

Louvers: Parallel slats on a lighting fixture used to prevent glare and direct light

Low-voltage: Reduction of regular household current (120 volts) to a lower voltage (usually 12-volt) using a transformer

Lumen (measured in footcandles): Measure of amount of light emitted (one lumen is the amount of light from one candle one foot away)

Magnetic transformer:

Medium base: Socket size for a regular household bulb

NEC code: National Fire Protection Association codes for wiring

Neck: Brass or decorative rod used to add space between a lamp base and the socket

Neutral wire: Wire that carries current from receptacle or fixture back to the fuse box to complete the circuit (usually white)

Outlet: Point at which electrical wire attach to fixtures, receptacles, or switches

Pendant: Light fixture that hangs from the ceiling

Polarized plug: Plug on portable lighting item with different shaped prongs to ensure that the hot and neutral wires can’t be reversed

Raceway: Exterior channel that allows wires to be run on the surface of a wall or ceiling

Rated life of bulb: Number of hours at which 50% of the bulbs will fail under standard conditions

Receptacle: Outlet that supplies power for plug-in electrical items

Reflector: Mirrored or polished surface designed to project light in a specific direction

Riser: Threaded brass rod that screws into the top of a harp to raise the lampshade

Romex cable: Romex is a common brand name for Nonmetallic (i.e. plastic) sheathing for wiring which carries hot, neutral and ground wires, both one and two circuit. It is used in dry, protected areas like stud walls, not underground. A similar cable, commonly called UF, has a heavier plastic sheathing and is suitable for underground uses, like outdoor lighting.

SAD (seasonal affective disorder): Depression that occurs in individuals due to lack of sunlight during winter months

Sconce: Light fixture that hangs on the wall

Semi-flush mount: Light fixture that hangs down from the ceiling less than 2’

Service panel: Main fuse box where electrical service enters the home

Set screw: Knurled-edge screw used to hold a glass shade tight in the fitter

Short: Spark resulting from neutral and hot wires touching each other causing a blown fuse or circuit breaker flipping to off

Silver crown bulb: Bulb with silver coating on the end to reduce glare

Single pole: Light switch in the wall where you can only cut on & off the light from that one location

Socket: Electrical component that connects to 2 electrical wires and has threads for light bulb to screw into

Socket reducer: Screw-in socket that attaches to another socket to reduce the size of the bulb base

Spider: Three top horizontal rods of a lampshade frame

Splice: Connection made by joining 2 or more wires

SPT2 wire: Technical term for lamp wiring cord

Starter: Magnetic coil that strikes an arc between electrodes when a fluorescent bulb receives electricity

Stripping: Removing insulation from electrical wires to allow a connection between wires

Three-way bulb: Bulb with 2 different wattage filaments, allowing you to turn on each separately or both together

Three-way switch: A light control switch that allows you to turn the fixture on and off from 2 different locations

Transformer: Electrical device that changes the amount of voltage in a wiring line

Magnetic Transformer: Larger & heavier transformer using copper around a steel core to step down elctricity from 120 volts to 12 volts. Requires special magnetic dimmer.

Electronic Transformer: Compact & lightweight and more efficient than magnetic transformer. Requires electronic low-voltage dimmer.

Turn knob: Brass or plastic screw-on knob used to switch a portable lamp on and off

Underwriters knot: A special kind of knot in 2 electrical wires to secure the wires from pulling out from the socket

UL: United Laboratories testing organization that issues guidelines and provides testing to ensure wiring safety

Vase cap: Brass or wood cap to cover the opening in the top of a vase when converting it to a lamp

Volt: Measure of electrical pressure in a circuit

Voltage drop: Loss of electrical current on long wiring runs

Washer: Open round disc in the center of the top horizontal rods of a lampshade

Watt: Measure of electrical power being used on a circuit (volts x amps = watts)

Wire nut: plastic-enclosed coil used to join the ends of 2 or more electrical wires

Zip cord: Electrical cord with 2 wires joined with grooved insulation between them

Lighting Techniques:

Downlighting: Light filtering downward from above casting shadows on the floor in a moonlight effect

Grazing: Positioning of a light source in a vertical direction close to a surface to highlight surface texture

Silhouetting: Light from behind to create an outlined effect of an item

Spotlighting: Highly focused beam of light

Task Lighting: Lighting that focuses light on areas where tasks are done (reading, make-up, cooking, etc.)

Uplighting: Technique of lighting an item from below, creating shadows above

Wall washing: Light up entire wall usually from at least 3’ away

Types of bulbs:

Delayed-start fluorescent tube: Type of fluorescent bulb that takes a few seconds to warm up

Fluorescent tube: A light source created by an ionization process and a coated glass tube

Halogen (quartz): Incandescent bulb filled with halogen gas to increase the intensity of the light and increase the life of the bulb

HID (high-intensity discharge): Mercury vapor, metal halide, or high-pressure sodium gases in pressurized glass container that produces light when electricity is applied

Incandescent bulb: Household bulb with a tungsten filament wire that lights when electricity flows through it

Neon: Bulb that contains an inert gas (neon) that glows when voltage is applied

Xenon: Similar to halogen but has Xenon gas and bare hands do not reduce life of the bulb

Tags: electrical, glossary, lighting

This entry was posted on Friday, January 16th, 2009 at 12:58 pm and is filed under Lighting Tips & Techniques. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.