| A | B |
|---|
| American Wire Gauge (AWG) | A scale of specified diameters and cross sections for wire sizing that is the standard wire-sizing scale in the United States |
| ampacity | The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating |
| antioxidant | A special compound that is applied to exposed aluminum conductors; its purpose is to inhibit oxidation |
| approved | When a piece of electrical equipment is approved, it means that it is acceptable to the authority having jurisdiction (AHJ) |
| bimetallic strip | A part of a circuit breaker that is made from two different metals with unequal thermal expansion rates; as the strip heats up, it will tend to bend |
| cabinet | An enclosure for a panelboard that is designed for either flush or surface mounting; a swinging door is provided |
| cable | A factory assembly of two or more insulated conductors that have an outer sheathing that holds everything together; the outside sheathing can be metallic or nonmetallic |
| circuit breaker | A device designed to open and close a circuit manually and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating |
| circular mils | The diameter of a conductor in mils (thousandths of inches) squared; the number of circular mils is the cross-sectional area of a conductor |
| connector | A fitting that is designed to secure a cable or length of conduit to an electrical box |
| copper-clad aluminum | An aluminum conductor with an outer coating of copper that is bonded to the aluminum core |
| device | A piece of electrical equipment that is intended to carry but not use electrical energy; examples include switches, lamp holders, and receptacles |
| device box | An electrical device that is designed to hold devices such as switches and receptacles |
| disconnecting means | A switch that is able to de-energize an electrical circuit or piece of electrical equipment; sometimes referred to as the “disconnect” |
| fitting | An electrical accessory, such as a locknut, that is used to perform a mechanical rather than an electrical function |
| fuse | An overcurrent protection device that opens a circuit when the fusible link is melted away by the extreme heat caused by an overcurrent |
| ganging | Joining two or more device boxes together for the purpose of holding more than one device |
| ground fault | An unintended low-resistance path in an electrical circuit through which some current flows to ground using a pathway other than the intended pathway; it results when an ungrounded “hot” conductor unintentionally touches a grounded surface or grounded conductor |
| handy box | A type of metal, surface-mounted device box used to hold only one device |
| insulated | A conductor that is covered by a material that is recognized by the National Electrical Code® as electrical insulation |
| plug | The device that is inserted into a receptacle to establish a connection between the conductors of the attached flexible cord and the conductors connected to the receptacle |
| pryout | Small parts of electrical boxes that can be “pried” open with a screwdriver and twisted off so that a cable can be secured to the box |
| raceway | An enclosed channel of metal or nonmetallic materials designed expressly for holding wires or cables; raceways used in residential wiring include rigid metal conduit, rigid polyvinyl chloride conduit, intermediate metal conduit, liquid tight flexible conduit, flexible metal conduit, electrical nonmetallic tubing, and electrical metallic tubing |
| Romex | A trade name for nonmetallic sheathed cable (NMSC); this is the term most electricians use to refer to NMSC |
| safety switch | A term used sometimes to refer to a disconnect switch; a safety switch may use fuses or a circuit breaker to provide overcurrent protection |
| service entrance | Consists of the conductors and equipment for delivering electric energy from the utility company to a house |
| sheath | The outer covering of a cable that is used to provide protection and to hold everything together as a single unit |
| short circuit | An unintended low-resistance path through which current flows around rather than along a circuit’s intended current path; it results when two circuit conductors come in contact with each other unintentionally |
| spliced | Connecting two or more conductors with a piece of approved equipment like a wirenut; splices must be done in approved electrical boxes |
| switch box | A name used to refer to a box that just contains switches |
| torque | The turning or twisting force applied to an object when using a torque tool; it is measured in inch-pounds or foot-pounds |
| utility box | A name used to refer to a metal, single-gang, surface-mounted device box; also called a handy box |
| wirenut | A piece of electrical equipment used to mechanically connect two or more conductors together |
