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
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
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
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.
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
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.