Plain definitions of 37 terms we use on the job in Victoria.
Term Index
Open any term below for a dedicated definition page.
AFCI is an Arc-Fault Circuit Interrupter, a circuit-protection device that detects electrical arcing and interrupts power before an arc can damage wiring or ignite nearby materials. An AFCI monitors the electrical pattern on a circuit and responds to irregular changes linked with damaged insulation, loose connections, or other arc-producing conditions.
Also called: Arc-Fault Circuit Interrupter
Ampacity is the maximum electrical current a conductor can carry under stated conditions without exceeding its permitted temperature. The rating depends on the wire material, size, insulation, installation method, and surrounding conditions. Electricians use ampacity to match conductors with circuit loads and protective devices during electrical wiring installation.
Also called: Current-Carrying Capacity
A ballast is an electrical component that regulates current in certain light fixtures, especially fluorescent fixtures. It helps the lamp start and keeps the current within a controlled range during operation. Without a compatible ballast, a fluorescent lamp may flicker, fail to start, overheat, or produce unstable light.
Also called: Light Ballast
Busbar is a conductive metal bar inside electrical equipment that distributes power to multiple circuits. In a residential panel, the busbar connects with circuit breakers so electricity can move from the service conductors to branch circuits. Its condition affects reliable power distribution, breaker seating, and the panel’s overall electrical performance.
Also called: Bus Bar
A circuit is a complete path that allows electrical current to move from a power source through connected equipment and back to its source. Conductors, protective devices, switches, and loads may form part of the path. A circuit can supply lighting, receptacles, appliances, or other electrical equipment within a defined system.
Also called: Electrical Circuit
Conduit is a protective channel that routes and shields electrical wires and cables. It may be made from metal or nonmetallic material and may run through walls, ceilings, floors, or exposed areas. Electricians select conduit based on the wiring location, physical conditions, connection method, and space available for the conductors.
Also called: Electrical Conduit
Copper Wire is a conductive material used to carry electrical current through circuits, equipment, and building wiring. Copper conducts electricity efficiently and bends easily during installation. Insulation surrounds the metal conductor in most building applications, helping separate energized parts from nearby conductors, enclosures, and people while supporting organized electrical connections.
Also called: Copper Wiring
A Dimmer Switch is a control device that adjusts the electrical power delivered to a compatible light fixture. The adjustment changes the fixture’s brightness without requiring a different lamp. Dimmer switches replace standard light switches in suitable circuits, but the switch, lamp, and fixture must work together for proper operation.
Also called: Dimmer
Electrical Load is the total demand that connected devices place on an electrical system at a given time. The demand depends on the equipment operating together, the power each device needs, and how that demand reaches the circuits, panel, and service equipment. Electricians assess load when planning safe capacity for a property.
Also called: Load
An electrical meter is a utility-installed device that measures the electricity a property receives from the power system. The meter records energy use and sends or displays that information for billing and system monitoring. It connects the utility supply to the building’s service equipment, but it is not the same as a breaker panel.
Also called: Electric Meter
An electrical short is an unintended low-resistance path that lets current bypass the normal circuit route. The fault can connect energized conductors, connect a conductor to grounded metal, or damage insulation. Excess current may trip a breaker, open a fuse, heat wiring, or create visible damage until the fault is corrected.
Also called: Short Circuit
An Electrical Splice is a connection that joins two or more electrical conductors within a wiring system. The connection may extend an existing wire, repair damaged wiring, or route power through a junction point. A proper splice uses a listed connector or approved joining method and remains protected inside an accessible enclosure.
Also called: Wire Splice
An electrical subpanel is a secondary panel that receives power from a main electrical panel and distributes it to designated branch circuits. The subpanel contains circuit breakers, busbars, and connections for grounded conductors. It expands circuit organization in a building while remaining supplied and protected by the main panel.
Also called: Subpanel, Sub Panel
A generator inlet is a fixed connection point that transfers electricity from a portable generator to a building’s transfer switch. The inlet is mounted outside or in another accessible location and connects to the generator with a heavy-duty cord. The transfer switch then directs selected generator power to approved building circuits.
Also called: Generator Inlet Box
A ground fault is an unintended electrical connection between an energized conductor and a grounded surface or conductor. The fault redirects some current away from its planned circuit path. This condition can create shock and fire hazards, so ground-fault protection can interrupt power when the circuit becomes unbalanced.
Also called: Ground-Fault Condition
A grounding electrode is a conductive connection between an electrical system and the earth. Common examples include metal water piping, structural metal, and grounding electrodes installed in soil. The electrode helps direct electrical fault energy and lightning-related surges away from equipment, while supporting a stable grounding path for the service.
Also called: Ground Rod
A ground wire is a conductive path that connects electrical equipment and enclosures to the grounding system. The path helps carry fault current away from exposed metal and toward the electrical source, allowing protective devices to respond. Ground wires usually connect with grounding terminals, metal boxes, panels, and grounding electrodes.
Also called: Grounding Conductor
Hot Wire is an energized conductor that carries electrical potential from a source toward a load, such as a receptacle, light, or appliance. The hot wire commonly works with a neutral wire to complete a circuit, while a grounding path supports fault protection. Its condition affects whether connected equipment receives power.
Also called: Live Wire
A Junction Box is an enclosure that protects and contains wire connections where electrical conductors join, split, or change direction. The enclosure keeps splices accessible for inspection and helps shield connections from contact, damage, and debris. Junction boxes support organized wiring in homes, commercial spaces, and other electrical installations.
Also called: Electrical Junction Box
An LED Driver is an electronic device that converts incoming electrical power into the controlled voltage or current an LED light needs. The driver helps regulate power so the light operates properly. Some drivers are built into the fixture, while others are installed separately near the light or in an accessible electrical enclosure.
Also called: LED Power Supply
Line Voltage is the electrical potential supplied to a building’s wiring system for operating equipment and fixtures. In indoor lighting, line voltage usually reaches a fixture through a branch circuit and connects directly to compatible lamps, switches, or drivers. The term distinguishes building supply power from lower-voltage control or signaling power.
Also called: Mains Voltage
A Load Center is a panel assembly that receives electrical power and distributes it through branch circuits in a building. It houses circuit breakers, a busbar, and connection points for grounded and grounding conductors. The load center gives each circuit overcurrent protection and provides an organized location for switching and servicing electrical circuits.
Also called: Breaker Box
A motion sensor is an electrical device that detects movement within a selected area and sends a signal to control connected equipment. In security lighting, the signal can switch a light on when a person, vehicle, or other moving object enters the detection zone. Common sensor types include passive infrared and microwave devices.
Also called: Occupancy Sensor
Neutral Wire is the grounded circuit conductor that carries current back from a connected load toward the electrical panel. It completes the normal path for electricity in many branch circuits. The neutral wire connects to the neutral bar in the panel and may serve receptacles, lighting, appliances, and other electrical equipment.
Also called: Neutral Conductor
Photocell is a light-sensitive electrical control that turns an outdoor lighting circuit on when surrounding light falls and turns it off when daylight returns. A photocell responds to ambient brightness, so landscape lights can follow the natural day and night cycle without manual switching. The device is commonly installed where it can sense open-sky conditions.
Also called: Dusk-to-Dawn Sensor, Photoelectric Cell
A receptacle is a wiring device that provides connection points for electrical plugs. Common household receptacles have slots for energized and neutral conductors, plus a grounding connection. The device transfers power from a branch circuit to a cord-connected appliance or tool. Receptacles may be standard, tamper-resistant, weather-resistant, or designed for special protection.
Also called: Electrical Outlet
A service entrance is the part of an electrical system that connects utility power to a building’s main electrical equipment. It includes the incoming conductors, connection point, and related equipment that deliver power to the main disconnect or service panel. The service entrance marks the boundary between the utility supply and the building wiring.
Also called: Electrical Service Entrance
A surge protector is an electrical device that limits brief voltage spikes and redirects excess energy away from connected equipment. A surge protector may serve one receptacle or an entire electrical system. Whole-home models connect at the electrical panel, where they help reduce damage from disturbances caused by utility switching, lightning, or nearby electrical faults.
Also called: Surge Suppressor
Terminal Block is a modular electrical connection point that joins and secures wires through clamping terminals inside an insulating body. Terminal blocks organize conductors, support branch connections, and allow circuits to be disconnected for testing or service. They appear in control panels, equipment enclosures, and other fixed wiring assemblies.
Also called: Terminal Strip
Thermal Overload is a protective condition in which excessive current or heat causes a motor circuit’s overload device to open. The device interrupts power before sustained overheating damages motor windings, conductors, or connected equipment. Thermal overload usually develops from prolonged overloading, restricted cooling, mechanical strain, or an electrical fault that raises operating current.
Also called: Overload Protection
A transfer switch is an electrical switching device that moves selected circuits between utility power and a generator source. The device helps keep the two power sources separated during generator operation. A transfer switch may operate manually or automatically, depending on its design and the connected generator system.
Also called: Generator Transfer Switch
A tripped breaker is a circuit breaker that has opened a circuit after sensing excessive current or a fault. The interruption stops power from reaching connected wiring and devices. A breaker may trip because of an overload, short circuit, or repeated heat buildup. Resetting the handle does not remove the underlying electrical problem.
Also called: Breaker Trip
Voltage Drop is the reduction in electrical pressure that occurs as current travels through a conductor or connection. The reduction can leave less voltage available at the connected equipment than the electrical system supplies. Conductor length, wire size, current demand, connection condition, and material resistance all affect the amount of drop.
Also called: Voltage Loss
Weatherhead is a weatherproof service-entrance fitting that covers the point where overhead electrical conductors enter a building. The fitting directs rain away from the service mast and helps protect the conductors and connection area. A Weatherhead usually sits above the roofline and forms part of an overhead electrical service entrance.
Also called: Masthead, Service Head
Wire Gauge is a measurement system that identifies a conductor's size and helps determine how much electrical current the conductor can carry. The gauge describes the conductor itself, not the insulation color or cable covering. Electricians use wire gauge with circuit requirements, conductor material, and installation conditions when selecting wiring.
Also called: Wire Size
Wire Nut is a twist-on connector that joins stripped electrical conductors inside an electrical box or enclosure. The connector uses an insulated, threaded shell to grip compatible wires together. Wire nuts come in different sizes and materials, so the connector must match the wire type, conductor count, and connection conditions.
Also called: Twist-On Wire Connector
A Wire Stripper is a hand tool that removes insulation from electrical conductors without cutting the metal wire. Its shaped notches match common wire sizes and help expose a clean section for a terminal, connector, or splice. Some models also cut wire, crimp terminals, or include cutters for small fasteners.
Also called: Wire Stripping Tool
