About > Glossary of Terms
Accessible
Box / Equipment capable of being serviced without removing finished surfaces
AFCI - Arc-Fault Circuit Interrupter
Device used to sense arcing in a circuit & if present, disconnects power from the source.
Al / Cu
Al - Aluminum Wiring or Cu - Copper Wiring
Ampacity
Amount of current in amps that wiring, devices, or equipment is rated
Bonding
Connected to establish electrical continuity and conductivity
Branch Circuit
The conductors between the last overcurrent protective device and the outlets or loads.
BX Wiring
Bundles of insulated wires sheathed in a very sturdy metallic “armor.”
Clearance
Usually refers to minimum distances required for electrical equipment
Circuit
Interconnection of components to provide an electrical path between two or more components.
Circuit Breaker
A protective device used to open a circuit when current exceeds a maximum value. In effect a reusable fuse.
C.O. Detector
Poisoning with carbon monoxide, a tasteless odorless gas that is a byproduct of combustion. Carbon monoxide acts as a poison by competing with oxygen for binding sites on hemoglobin
Cold Water Ground
Conductor from main service to water piping for service grounding
Conductor
Usually a metallic substance capable of transmitting electricity with little resistance. The best conductor at normal temperature ranges is silver. The most common is copper. Some other recently discovered substances called super conductors actually have zero resistance at extremely low temperatures.
Conduit
A plastic or metal channel used to conceal wires or cables from one point to another.
Control Wiring
Wiring not associated with providing power to an electrical device used to control its operation
Current
The flow of electricity commonly measured in amperes.
Device
A component or part. Usually referring to a switch or receptacle
Disconnecting Means
A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply
Double Tapped
When two wires are connected under one screw or terminal inside an electric panel.
Draw
Amount of current under use at circuits end.
Efficiency
The amount of power delivered to the load of an amplifier as a percentage of the power required from the power supply.
Electricity
The flow of electrons through a conductor
Enclosure
The case or housing of apparatus surrounding an installation to prevent personnel from accidentally contacting energized parts or to protect the equipment from physical damage.
Energy
The capacity for, or the ability to do, mechanical work. Electrical energy is measured in kilowatt-hours for billing purposes.
Fault
A short circuit.
Feeder
Circuit conductors between the service equipment and the last downstream branch circuit overcurrent protective device.
Footer Ground
Conductor from main service to the homes footing for service grounding
Fuse
A protective device in the current path that melts or breaks when current exceeds a predetermined maximum value
Grade
In construction, referring to a specific exterior area being at a permanent level / height
Ground Rod
A metal rod (typically 5/8 inch diameter) that is driven into the earth (typically 8 feet deep) and is mechanically connected to the grounding conductor
Ground
An intentional or accidental conducting path between an electrical system or circuit and the earth or some conducting body acting in place of the earth. A ground is often used as the common wiring point or reference in a circuit.
GFI / GFCI - Ground Fault Circuit Interrupter
A device designed to interrupt the flow of power when a minuscule imbalance is detected between the flow and return of current.
Hot Spot
Referring to an area that is warmer than ambient surroundings and / or operating at temperature hotter than recommended.
IC Rated Recess Light Fixture
IC rated recess light housing is designed for installation in areas where direct contact with building insulation is permitted.
Isolated
When a non conducting material is used to isolate conducting materials from one another.
Junction Box
A box containing splices in cables. Has a removable cover that must be accessible (cannot be buried in ceilings and walls).
KO Filler
A partially prepunched opening in a box that is removed to allow the entry of cable. A knockout that is mistakenly opened or is open because a cable is removed must be filled with a knockout seal.
KW
Unit of power equal to 1000 watts. Abbreviation for kilowatt
Listed
An electrical device or material that has been tested by a recognized organization and shown to meet appropriate standards. Many local governmental authorities require that installed electrical products be listed. A well-known listing organization is Underwriters Laboratories (UL).
Load
A device which consumes electrical power and is connected to a source of electricity.
Main Service
Electrical service equipment that provides the first means of overcurrent protection of your home
MC Wiring
Bundles of insulated wires sheathed in a very sturdy metallic “armor.” with an insulated green grounding conductor
N.E.C.
Abbreviation for the National Electrical Code.
Neutral
A conductor of an electrical system which usually operates with minimal voltage to ground. Depending on the type of system, it may carry little current or only unbalance current. Systems that have one conductor grounded use the neutral for this purpose.
Neutral Imbalance
Homes circuit breakers should be install such a manner that under normal use, an equal amount of current will be drawn from each of the two electrical phases provided by you power company. If this is not the case, the imbalance of the current of one phase will be carried by the service neutral of the service thereby generating heat and loss of efficiency which equates to higher monthly power company invoicing.
Outlet
A point on the wiring system at which current is taken to supply utilization equipment
Overcurrent
Any current beyond the continuous rated current of the conductor or equipment. This may be value slightly above the rating as in the case of an overload, or may be far above the rating as in the case of a short circuit.
Overload
Operation of electrical equipment above its normal full-load rating or of a conductor above its rated Ampacity. An overload condition will eventually cause dangerous overheating and damage.
Phase
In electrical engineering, single-phase electric power refers to the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison.
Power
The rate at which work is performed or that energy is transferred. Electric power is commonly measured in watts or kilowatts. A power of 746 watts is equivalent to 1 horsepower.
Raceway
A plastic or metal channel used to conceal wires or cables from one point to another.
Romex
A brand of nonmetallic-sheathed cable.
SEC
Cable for the point where the electrical service enters the house, becoming your responsibility instead of the electric companies.
Service
The equipment and conductors that transmit electricity from the utility supply system to the building being served.
Service Panel
Usually installed near the service entrance, this panel contains the main switch or breaker to disconnect the house system from the power source as well as circuit breakers
Short Circuit
A low resistance connection unintentionally made between points of an electrical circuit which may result in current flow far above normal levels.
Subpanel
Acts as a waypoint between the main service panel and branch circuits further down the line.
Surge Protection
A device for limiting surge voltages by discharging or bypassing surge current.
Switch
A device designed to open, close, or both, one or more electrical circuits
Tap
Point of termination made prior to the final overcurrent protection device to supply power to alternate load.
Tandem Breaker
Tandem breakers, often called split breakers or double breakers, provide two separate circuits in the space of a regular sized breaker opening.
Thermal Protector - Recess Lighting
Provides cutoff off power to fixture lamp due to overheating
Terminal
Provision a convenient means of connecting individual electrical wires.
Termination
Making final connection at the end of a wire or cable
UL
Underwriters Laboratories - a non-profit organization that was established by the insurance industry to test electrical devices for safety.
Under Load
Refers to full operation of existing circuit / s
Voltage
The voltage between two points is a short name for the electrical force that would drive an electric current between those points
Voltage Drop
A voltage reduction due to impedances between the power source and the load.
Watt
A unit of power equal to the rate of work represented by a current of one ampere under a pressure of one volt.
W.P. Weatherproof
Constructed or protected so that exposure to the weather will not interfere with successful operation