Plain definitions of 37 terms we use on the job in Victoria.
Term Index
Open any term below for a dedicated definition page.
An Arc-Fault Circuit Interrupter is a protective device that detects electrical arcing and disconnects power before arcing can damage wiring or start a fire. An AFCI monitors the electrical pattern on a circuit and responds to unwanted arcs that ordinary overcurrent protection may not detect. AFCIs commonly protect branch circuits serving living areas.
Also called: AFCI
An arc fault is an unintended electrical discharge across a gap or damaged connection, producing heat that can damage wiring and nearby materials. The discharge may occur when conductors loosen, insulation wears away, or connections become compromised. Arc faults differ from ordinary overloads because current can remain below a standard breaker’s trip level.
Also called: Arc Flash
An Automatic Transfer Switch is a control device that moves selected electrical loads between a utility supply and a backup generator. It monitors the normal power source, signals the generator when needed, and transfers connected circuits after backup power becomes available. When utility power returns, the switch moves those circuits back.
Also called: ATS
A backstab connection is an electrical wiring method that secures a solid conductor in a spring-loaded opening on the rear of a receptacle or switch. The spring clip holds the wire without a visible terminal screw. This connection appears in branch-circuit wiring and can develop contact problems if the wire or device becomes loose.
Also called: Back Wiring
Ballast is an electrical component used with certain lighting systems to control current and help a lamp start and operate correctly. Traditional fluorescent fixtures use magnetic or electronic ballasts. Some LED retrofit lamps require a compatible ballast, while other LED systems bypass or remove the ballast and connect to an LED driver or line voltage.
Also called: Light Ballast
Battery Inverter is a power conversion device that changes the direct-current electricity stored in a home battery into alternating-current electricity for household circuits. The device can also convert alternating-current power into direct-current power during charging. In backup systems, controls within the inverter help supply selected loads when normal utility power is unavailable.
Also called: Inverter Charger
Busbar is a conductive metal strip or assembly inside electrical equipment that distributes power to connected circuits. A busbar provides a common connection point for breakers, feeders, or other conductors. Panels may contain separate busbars for energized conductors and neutral connections, depending on the equipment design and electrical system.
Also called: Bus Bar
Cable Clamp is a fitting that secures an electrical cable where the cable enters an enclosure, box, panel, or device. The clamp holds the cable in place, protects the cable jacket from abrasion, and helps prevent pulling force from reaching internal wire connections. Cable clamps may attach with threads, screws, or pressure.
Also called: Cable Connector
Circuit Load is the electrical demand placed on a branch circuit by connected devices and equipment. The demand depends on the power each device needs while operating. A circuit load helps determine whether existing conductors, connections, and protective devices can serve the equipment without excessive heating, nuisance tripping, or unstable operation.
Also called: Electrical Load
Conduit is a protective pathway for electrical conductors. It consists of tubing or raceway that routes wires through walls, ceilings, exposed areas, or underground spaces. Conduit may be rigid or flexible and can be made from metal or nonmetallic material. Its size, fittings, and routing must suit the wiring installation.
Also called: Electrical Conduit
Critical Loads are selected electrical circuits or devices that receive priority power during an outage. A backup system supplies these loads while leaving nonessential circuits disconnected or inactive. Common examples include refrigeration, medical equipment, communications equipment, lighting, and selected receptacles. The list depends on household needs, backup capacity, and the design of the electrical system.
Also called: Essential Loads
A Dimmer Switch is a wall control that adjusts the brightness of a connected light fixture. It changes the electrical power delivered to compatible lighting, allowing you to select a softer or brighter setting. Dimmer switches may serve a single light, several fixtures, or a lighting zone, depending on circuit design and device compatibility.
Also called: Dimmer
Electrical Bonding is the practice of connecting conductive metal parts so they share the same electrical potential and provide a controlled path for fault current. The connections may join equipment enclosures, metal raceways, service components, and grounding conductors. Bonding supports coordinated operation between the electrical system and its grounding paths.
Also called: Bonding
Electrical Grounding is a planned connection between an electrical system and the earth or another conductive path that can carry fault current safely away from energized parts. Grounding helps stabilize voltage, supports protective device operation, and reduces the chance that exposed metal parts remain energized during a wiring fault.
Also called: Grounding
An enclosure is a protective case that surrounds electrical equipment, wiring, or connections. It helps shield energized parts from accidental contact, dust, moisture, and physical damage. Electrical enclosures may be made from metal or nonmetal materials and can contain a panelboard, junction point, control device, or other equipment.
Also called: Electrical Enclosure
A fan capacitor is an electrical component that stores and releases energy to help a ceiling fan motor start, run, and change speed. The capacitor creates a phase shift in the motor windings, which supports the rotating magnetic field. A damaged capacitor can cause weak airflow, humming, slow operation, or limited speed control.
Also called: Ceiling Fan Capacitor
A ground rod is a metal electrode installed in the earth and connected to a building’s electrical grounding system. The rod provides a path for electrical energy to dissipate into the soil during certain fault or surge conditions. Its effectiveness depends on proper placement, connection, soil conditions, and coordination with the entire grounding system.
Also called: Grounding Electrode
Hot Conductor is an energized wire that carries electrical potential from a source toward a load. The conductor may feed a receptacle, switch, light, appliance, or panel circuit. Its voltage is measured relative to a neutral or grounding reference, and its condition affects whether equipment receives power as intended.
Also called: Hot Wire, Live Wire
Inverter Islanding is a condition in which an inverter keeps supplying power to a section of an electrical system after the utility grid has lost power. Detection and disconnection controls separate the inverter from the grid, helping protect utility workers and prevent unstable voltage or frequency on the isolated circuit.
Also called: Islanding
Junction Box is an enclosed electrical housing where conductors are joined, routed, or divided. The enclosure protects wire connections from contact and helps keep wiring organized. Junction boxes may serve lighting, receptacle, switch, or circuit connections. They remain accessible for inspection, testing, repair, and future wiring changes.
Also called: Electrical Box
An LED Driver is an electrical device that converts incoming power into the controlled current or voltage an LED light needs. The driver helps the light operate safely and consistently. Depending on the fixture, the driver may be built into the light or installed as a separate component nearby.
Also called: LED Power Supply
Line voltage is the electrical potential supplied directly by a building’s branch circuit to power equipment and fixtures. In indoor lighting, line voltage commonly feeds luminaires, switches, and dimmers through the building wiring. The term distinguishes full circuit voltage from low-voltage power supplied through a transformer or driver.
Also called: Mains Voltage
Load Calculation is the process of estimating the electrical demand that a building and its circuits may place on a service. The calculation considers existing equipment, planned additions, and how electrical loads operate together. Electricians use the result to assess whether a service, panel, or feeder can support an upgrade safely.
Also called: Electrical Load Calculation
MC Cable is an electrical wiring assembly that combines insulated conductors with a flexible metal armor jacket. The armor protects the conductors from physical damage and provides a grounding path when properly connected. Electricians use MC Cable for exposed or concealed wiring where its factory-assembled construction suits the building layout and installation method.
Also called: Armored Cable, Metal-Clad Cable
A neutral wire is a current-carrying conductor that completes the return path from an electrical load to the source. In common branch circuits, the neutral connects with the grounded conductor system at the service equipment. The neutral normally remains near ground potential, but it can carry current and should not be treated as harmless.
Also called: Neutral Conductor
An ohm is the unit used to express electrical resistance, which describes how strongly a material or component opposes current. Resistance affects the relationship between voltage and current in a circuit. Electricians use ohm readings to assess wires, heating elements, motor windings, switches, and other parts during electrical troubleshooting.
Also called: Ohms
Photocell is a light-sensitive electrical control that switches a connected lighting circuit according to surrounding brightness. It commonly turns outdoor lights on at dusk and off at dawn. A photocell helps automate security lighting without a manual switch, timer, or daily adjustment. Its operation depends on light reaching the sensor.
Also called: Dusk-to-Dawn Sensor, Photoelectric Sensor
Power Factor is a measure of how effectively an electrical load converts supplied power into useful work. The measure compares working power with the total power drawn from the electrical system. Motors, transformers, and other inductive equipment can draw reactive power, which supports operation but does not directly produce useful output.
Also called: PF
Recessed Housing is the enclosure installed above a ceiling or inside a wall to hold a recessed light fixture. The housing supports the trim, protects wiring connections, and helps separate the fixture from nearby building materials. Its design must match the ceiling location, light type, insulation conditions, and approved installation method.
Also called: Can Housing, Recessed Light Housing
A service entrance is the point where electrical power enters a building from the utility system and connects to the building’s main electrical equipment. It includes the service conductors, meter connection, main disconnect, and related enclosure. This equipment establishes the boundary between utility-supplied power and the wiring that distributes electricity throughout the property.
Also called: Electrical Service Entrance
Short Circuit is an unintended electrical path with very low resistance that lets current bypass part of the normal circuit. The sudden current rise can trip a circuit breaker, damage wiring, or create heat at a weak connection. A short circuit may occur between energized conductors or between an energized conductor and ground.
Also called: Electrical Short
A standby generator is a permanently installed backup power system that starts automatically when utility power fails. It uses an engine to produce electricity and connects to selected building circuits through a transfer switch. Standby generators can support essential equipment, appliances, or broader electrical loads, depending on system design and available capacity.
Also called: Backup Generator
A Terminal Block is an electrical connection device that joins wires to equipment or other circuits through separate conductive terminals. An insulating body holds the terminals in place and helps keep each connection organized. Terminal blocks support orderly wiring in control panels, distribution equipment, machinery, and other fixed electrical installations.
Also called: Terminal Strip
Thermal Imaging is a noncontact inspection method that uses an infrared camera to show heat patterns across surfaces. Electrical professionals read these patterns to identify unusual warmth at panels, connections, conductors, and equipment. The method helps locate areas that deserve closer testing, but an image alone does not prove the exact cause of a fault.
Also called: Infrared Inspection, IR Inspection
Voltage drop is the reduction in electrical pressure that occurs as current travels through a conductor, connection, or device. The reduction results from resistance in the circuit. Excessive voltage drop can prevent equipment from receiving the voltage needed for reliable operation, causing dim lights, weak motor performance, heat, or intermittent operation.
Also called: Voltage Loss
Wire Gauge is a standardized way to describe a conductor’s thickness and current-carrying capacity. The gauge designation helps identify whether a wire suits a circuit’s load, installation method, and expected voltage drop. Smaller gauge numbers generally indicate thicker conductors, while larger numbers indicate thinner conductors within the American Wire Gauge system.
Also called: Wire Size
A wire nut is an insulated twist-on connector that joins compatible electrical conductors inside a wiring enclosure. The connector grips the stripped wire ends as the cap turns, creating a compact mechanical and electrical connection. Wire nuts come in different sizes and types to match conductor material, wire range, and connection needs.
Also called: Twist-On Wire Connector
