Definitions

AFCI
Arc Fault Circuit Interrupter- A device that de-energizes the circuit when an arc fault is detected.
Ampacity
In the electrical code, refers to the current, measured in amperes, or amps, that a conductor (a wire) can carry continuously under the conditions of use without exceeding its temperature rating - in other words, the ampacity of a #14 gauge copper wire intended for residential electrical wiring is 15 Amps because that's the amount of current that the wire can carry without getting too hot. "Too hot" means a temperature that could damage the wire insulation and thus reduce its safety.
Amp
Amps, ampere - The unit expressing the rate of flow of an electric current. Basically, this is how much power something uses. We use this to determine the size of services, conductors (wires), and over current devices (circuit breakers and fuses).
Appliance
Utilization equipment that is normally built in standardized sizes or types and isinstalled or connected as a unit to perform one or more functions.Examples would be a clothes dryer, microwave, water heater, range/oven etc.
Branch Circuit
The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
Conductor
1)A wire or combination of wires suitable for carrying an electrical current. Conductors may be insulated or bare. 2) Any material that allows electricity to flow through it.
Feeder
All circuit conductors between a power supply source and the final branch-circuit overcurrent device.
GFCI
Ground fault circuit interrupter- a device that de-energizes the circuit within a specified period of time when a current-to-ground condition is sensed.
GRC
Galvanized Rigid Conduit- Heavy duty steel conduit, in a house it's used mainly just for the service riser.
Line (side)
The side or direction from which the power is feeding from or coming in, usually the top or left.
Load (side)
The side or direction to which power is feeding to or going out, usually the right or bottom.
NEC
The National Electrical Code, also known as NFPA 70. This is the book that contains the rules we must follow when performing electrical installations. Can be amended by local codes.
Ohm
A unit of electrical resistance defined as the resistance of a circuit with a voltage of one volt and a current flow of one ampere.
Overcurrent
Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit or ground fault.
Overcurrent Device
The device, usually a circuit breaker or fuse, protecting an item from an overcurrent condition.
PVC
Rigid nonmetallic conduit. A plastic style raceway glued together with appropriate fittings, used for protecting conductors.
Pigtail
A short (6-12 inches) piece of conductor connected to other conductors for the purpose of connecting a device.
SE Cable
Service entrance cable, a cable with an outer sheath, usually grey, enclosing two insulated power conductors and one un-insulated neutral conductor.
SER Cable
Service entrance cable round, similar to SE cable, but has 3 insulated conductors (two power, one neutral), and one un-insulated ground conductor.
Service
The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premise served. The service includes the electrical meter, main panel and associated wiring.
Standard Breaker Size
The size or sizes that are standard for a breaker to be designated as. As listed in the NEC: 15, 20, 25, 30, 35, 40, 45, 50,60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300.
VA
Electrical capacity or electrical load, expressed as Volts * Amps.
Volt
A unit of electromotive force. The electrical potential needed to produce one ampere of current with a resistance of one ohm.
Watt
Measure of the amount of electricity being used - a rate of electrical power consumption. For calculation purposes, essentially the same as VA.