Alternator: An electric generator that produces alternating current.
American Wire Gauge (AWG) : A standard measure representing the size of a wire (a larger number represents a smaller wire).
Analog: A unit of measure that utilizes varying physical restrictions.
Arc Tube: A tube enclosed by a glass made of clear quartz that contains an arc stream.
Ballast: An electrical device used with fluorescent lamps to supply sufficient voltage to operate the lamp but also then limits the current during operation.
Branch Circuit: Conductors that protect circuits and outlets.
BTU (British Thermal Unit) : The standard unit for measuring heat quantities.
Capacitor: A device that stores electrical charge.
Circuit Breaker: A device designed to open and close a circuit without causing damage to itself.
Code Corrections: Procedures used to correct wiring that does not meet proper safety conditions.
Continuous Load: A load whos maximum current is expected to continue for 3 hours or more.
Controller: A device that serves to regulate the electric power delivered to a connected apparatus.
Current: The flow of electricity measured in amperes.
Daylight Compensation: An energy-saving dimming system that reduces lamp output when in the presence of natural light.
Dimmer: A device used to vary the brightness of lamps.
Electric Resistance Heating: A type of heating system that generates heat by passing current through a conductor, often used in baseboard heating systems.
Energy Efficiency Ratio (EER) : The ratio of the cooling capacity of the air conditioner to the total electrical input in watts.
Energy-saving Ballast: A magnetic ballast designed to operate more efficiently than "standard magnetic" ballasts.
Fault: A short circuit in an electrical system.
Four-Way Switch: A wall switch allowing three switches to control one lighting system.
Ground: A connection between an electrical circuit and the earth.
Hard Wired: A light fixture permanently connected to an electrical source with a cord.
High Output (HO) : A lamp or ballast designed to operate at higher currents in order to produce more lumens.
High-Tech Troubleshooting: A procedure used to identify any electrical problems.
Kilowatt (kW) : Real power delivered to a load.
LED: Light Emitting Diode: a small, energy-efficient electronic light that has a very long life.
Limit Switch: A switch used to alter the electric circuit.
Load Switching: Transferring a load from one source to another.
Low Voltage: A wiring system that provides power to an electronic device operating on a voltage level lower than the standard 110 volts.
National Electrical Code (NEC) : A guideline used for safeguarding people/property from electrical hazards.
Rated Life: The time at which half of a certain kind of lamp will burn out.
Relay: A device that switches a load on or off due to small changes in its current.
Tap: A connection made from outside the wiring system.
Three-Way Switch: A wall switch allowing two switches to control one lighting system.
Transfer Switch: An electronic device that can disconnect from one power source in order to connect to another.
Transformer: A device wherein electromagnetic induction transfers electrical energy from one circuit to another.
Transient: A high amplitude, short duration pulse overlaid onto the normal voltage.
UL: Underwriters Laboratories, Inc: a not-for-profit safety organization.