Electrical trades vocabulary

Amp / Ampere (A)

A measurement of how much electrical current is flowing.

Circuit

A complete path that electricity can flow through.

Current

The flow of electricity through a conductor or circuit. Current is measured in amps.

Load

Anything that uses electrical power, such as a light, motor, heater, or appliance.

Ohm (Ω)

The unit used to measure electrical resistance.

Power

The rate at which electrical energy is being used or delivered. Electrical power is usually measured in watts.

Resistance

Anything that opposes or limits the flow of electrical current.

Voltage / Volts (V)

The electrical force or potential that can cause current to flow through a circuit.

Watt (W)

A unit used to measure electrical power.

Cable

A group of conductors assembled together, usually inside a protective outer covering.

Conductor

A material that electricity can easily flow through. Electrical conductors are commonly made from copper or aluminum.

Equipment Grounding Conductor (EGC)

A conductor that provides a safe path for fault current from electrical equipment. It is commonly a bare, green, or green-with-yellow-stripe conductor (remember the professional term is conductor, not wire).

NEC: Article 100; Article 250

Hot

A common jobsite term for a conductor that carries voltage. The more accurate term is usually ungrounded conductor.

Insulation

Material around a conductor that helps keep electricity from going where it should not go.

Neutral

A conductor that provides a return path for current in many electrical circuits. You may also hear it referred to as the grounded conductor, although these terms are not always interchangeable.

NEC: Article 100; Article 200

Romex / Type NM Cable

“Romex” is a commonly used trade name for a type of nonmetallic-sheathed cable used in residential construction. Type NM cable is the more accurate electrical term.

NEC: Article 334

Splice

A connection where two or more conductors are joined together.

NEC: 110.14

Wire

A common jobsite term often used for an individual electrical conductor. Conductor is the preferred professional term when referring to the material that carries electrical current.

Conduit

A tube or pipe-like raceway used to route and protect electrical conductors.

Coupling

A fitting used to connect two pieces of conduit or raceway together.

EMT

Electrical Metallic Tubing. A lightweight metal raceway commonly used in commercial electrical work.

NEC: Article 358

Flex

A general jobsite name for flexible raceway. Several different types of flexible raceway exist.

Raceway

An enclosed pathway designed to hold and protect electrical conductors or cables.

NEC: Article 100

Breaker / Circuit Breaker

A protective device that automatically opens a circuit when too much current flows. It can also be used to manually turn a circuit on or off.

NEC: Article 100; Article 240

Breaker Box

An informal name for the electrical panel containing circuit breakers. Panelboard or panel is the preferred professional term.

Dead Front

A cover or construction that keeps a person from accidentally touching energized parts during normal operation.

NEC: Article 100

Junction Box / J-box

A box where electrical conductors can be connected, spliced, or routed.

NEC: Article 314

Outlet

A point in an electrical system where power is supplied to equipment. An outlet is not necessarily a receptacle.

NEC: Article 100

Panel / Panelboard

Equipment that distributes electrical power to different circuits and usually contains circuit breakers.

NEC: Article 100; Article 408

Receptacle

The device that a cord-and-plug piece of equipment plugs into. It is what people often mean when they say “outlet.”

NEC: Article 100; Article 406

Switch

A device used to open, close, or control an electrical circuit.

NEC: Article 404

Branch Circuit

The conductors between the final circuit breaker or fuse and the outlets or equipment they supply.

NEC: Article 100; Article 210

Disconnect / Disconnecting Means

A device or other means used to disconnect electrical equipment or a circuit from its power source. Disconnecting means is the terminology students will encounter in the NEC.

NEC: Article 100

Feeder

Conductors that carry power from service or other distribution equipment to downstream distribution equipment.

NEC: Article 100; Article 215

Ground Fault

An unintended electrical path between an energized conductor and ground or grounded metal.

NEC: Article 100

Overcurrent

More current flowing through a conductor or device than it is designed to safely handle.

NEC: Article 100; Article 240

Service

The conductors and equipment that bring electrical power from the serving utility into a building or property.

NEC: Article 100; Article 230

Short Circuit

An unintended electrical connection that allows a large amount of current to flow along the wrong path.

Bonding

Connecting conductive parts together electrically so they can safely carry fault current.

NEC: Article 100; Article 250

Ground

A connection to the earth or to a conductive object that serves as a connection to earth.

NEC: Article 100; Article 250

Ground Rod

A metal rod driven into the earth and used as part of a grounding electrode system.

NEC: 250.52(A)(5); 250.53

Grounding

Connecting an electrical system or equipment to earth.

NEC: Article 100; Article 250

Fish Tape

A long, flexible tool used to pull electrical conductors through conduit or enclosed spaces.

Land

Jobsite language meaning to connect a conductor to its proper terminal.

Make Up

Jobsite language for connecting and arranging conductors in a box, panel, or piece of equipment.

Rough-In

The stage of construction when boxes, cables, conduit, and other electrical components are installed before walls and ceilings are finished.

Terminate

To make the final connection between a conductor and a device, terminal, or piece of equipment.

Arc Flash

A dangerous release of heat and energy caused by an electrical arc. An arc flash can cause severe burns and other serious injuries.

NEC: 110.16; see NFPA 70E for workplace electrical safety practices

De-energized

Disconnected from electrical power. Workers still need to verify that voltage is absent before treating electrical equipment as safe.

Energized / Live

Connected to an electrical power source or having voltage present.

NEC: Article 100

GFCI

Ground-Fault Circuit Interrupter. A protective device that quickly shuts off power when it detects certain current leaving its intended path, helping protect people from electric shock.

NEC: Article 100; 210.8

LOTO / Lockout-Tagout

A safety process used to control hazardous energy and help prevent equipment from being unexpectedly energized while someone is working on it.

PPE

Personal Protective Equipment. Safety equipment worn to help protect workers from workplace hazards.

High Pot / Hipot

Jobsite shorthand for a high-voltage test used to check electrical insulation. The more formal term is a dielectric withstand test.

Juice

Slang for electricity or electrical power. More specific terms such as voltage, current, power, or energized should be used when appropriate.

Snake

Jobsite slang for a fish tape or for using one to route or pull conductors through a pathway.