Ladder Cable Tray - see definition for Cable Tray.

Lampholder - A device constructed for the mechanical support of lamps and for connecting them to circuit conductors.

Lighting Fixture (luminaire) - special terminology and types:

Cabinet lighting System - a complete, extra-low-voltage lighting assembly consisting of a plug-in power supply having a Class 2 output, luminaires, wiring harness, and connectors, intended for surface or recessed mounting under a shelf or similar structure or in an open or closed cabinet.

Cable Lighting System - a permanently connected extra-low-voltage lighting system that comprises an isolating-type transformer with bare secondary conductors for connection to one or more luminaire heads.

Landscape Lighting System - an extra-low-voltage outdoor lighting system.

Recessed Luminaire - a luminaire that is designed to be either wholly or partially recessed in a mounting surface.

Recessed luminaire, Type IC (intended for insulation contact) - a recessed luminaire designed for installation in a cavity filled with thermal insulation and permitted to be in direct contact with combustible materials and insulation.

Recessed luminaire, Type IC, inherently protected (intended for insulation contact) - a recessed luminaire that does not require a thermal protective device and cannot exceed the maximum allowable temperatures under all conceivable operating conditions.

Recessed luminaire, Type Non-IC (not intended for insulation contact) - a recessed luminaire designed for installation in a cavity with minimum dimensions and spacings to thermal insulation and combustible material.

Recessed luminaire, Type Non-IC, marked spacings (not intended for insulation contact) - a recessed luminaire designed for installation in a cavity where the clearances to combustible building members and thermal insulation are specified by the manufacturer.

Undercabinet Lighting System - a complete, extra-low-voltage lighting assembly consisting of a plug-in power supply having a Class 2 output, luminaires, wiring harness, and connectors, intended for surface mounting only under a shelf or similar structure or in an open or closed cabinet.

Lightning - An atmospheric electrical phenomenon associated with thunderstorms; a surge on a system that results from energy being impressed on the system.

Liquid-Filled Transformer - A transformer in which the core and coil are immersed in a liquid which acts as both a cooling and insulating medium.

Liquid-Tight Flexible Conduit - see definition for Conduit.

Limit Switch - A switch that is operated by some part or motion of a power-driven machine or equipment to alter the electric circuit associated with the machine or equipment.

Livefront - Apparatus with bus work and connections exposed to the operator.

Load - The load of a transformer is the power, in kVA or volt-amperes, supplied by the transformer. Lagging Load: inductive type load. Leading Load: capacitive load.

Load Curve - A curve showing instantaneous demand (kVA or MVA) versus time. Curves are usually plotted for one day or one week. Integrating the load curve will provide the amount of energy consumed.

Load Factor - Represents how efficiently the electrical system capacity is being used. The higher the load factor the higher the efficiency.

Load Switching - Transferring the load from one source to another.

Loadbreak - The ability of a switching device to disconnect a load current without damage.

Loadmake - The ability of a switching device to connect to a specific load current without damage.

Location:

Damp Location - An exterior or interior location that is normally or periodically subject to condensation of moisture in, on, or adjacent to electrical equipment and includes partially protected locations under canopies, marquees, roofed open porches, and similar locations.

Dry Location - A location not normally subject to dampness, but may include a location subject to temporary dampness as in the case of a building under construction, provided ventilation is adequate to prevent an accumulation of moisture.

Wet Location - A location in which uncontrolled liquids may drip, splash, or flow on or against electrical equipment.

Hazardous Location - see definition for Hazardous Location.

Ordinary Location - A dry location in which at normal atmospheric pressure and under normal conditions or use, electrical equipment is not unduly exposed to damage from mechanical causes, excessive dust, moisture or extreme temperatures, and in which electrical equipment is entirely free from the possibility of damage through corrosive, flammable, or explosive atmospheres.

Low-Energy Power Circuit - A circuit other than a remote control or signal circuit that has the power supply limited in accordance with the requirements for Class 2 remote control circuits.

Low-Voltage - see definition for Voltage.

Low-Voltage Protection - A device that operates on the reduction or failure of voltage to cause and maintain the interruption of power to the main circuit.

Low-Voltage Release - A device that operates on the reduction or failure of voltage to cause interruption of power to the main circuit, but not to prevent its re-establishment on the return of voltage to a safe operating value.

Luminaire - A complete lighting unit designed to accommodate the lamp(s) and to connect the lamp(s) to a power supply (see definition for Lighting Fixture).

LV - Low Voltage, see definition for Voltage.