Plain definitions of 35 terms we use on the job in Riverside.
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 an arc can damage wiring or start a fire. An arc-fault circuit interrupter monitors the electrical pattern on a circuit and responds to irregular changes that may signal damaged insulation, loose connections, or faulty cords.
Also called: AFCI
Arc Flash is a sudden electrical discharge through air between energized conductors or a conductor and ground. The discharge releases intense heat, light, sound, and pressure. Arc flash can occur when a fault creates an unintended path for current. The event can damage equipment and injure people near the electrical source.
Bonding is the intentional connection of conductive metal parts so those parts remain at the same electrical potential. In pool electrical work, bonding connects metal components such as a pool shell, ladder, handrail, equipment housing, and reinforcing steel to a bonding network. The network helps provide a controlled path for unwanted electrical current.
Also called: Electrical bonding
Busbar is a rigid metal conductor inside an electrical panel that distributes power between the main incoming connection, circuit breakers, and connected circuits. A busbar usually has a protected mounting system and connection points for breakers or conductors. Its condition affects how reliably an electrical panel transfers current to branch circuits.
Also called: Bus bar
Bus Duct is a factory-assembled electrical distribution system that carries power through enclosed metal housing. It contains insulated or separated busbars that connect equipment across commercial or industrial spaces. Bus duct can replace multiple large conductors in suitable layouts, support organized power distribution, and provide access points for approved plug-in devices.
Also called: Busway
A cable tray is a support system that routes and protects electrical cables in commercial and industrial spaces. The open framework may be made from metal or other approved materials. Cable trays organize cable runs above ceilings, along walls, or across equipment areas while allowing access for inspection, maintenance, and future changes.
A circuit directory is a written guide that identifies which rooms, appliances, or outlets each circuit breaker controls. The directory is usually placed inside or beside an electrical panel. Accurate entries help you select the correct breaker during troubleshooting, repair, maintenance, or an electrical emergency without guessing.
Also called: Panel schedule
Conduit is a protective raceway that surrounds and guides insulated electrical wires or cables. It may consist of metal or nonmetallic tubing and can run through walls, along surfaces, or underground. Conduit helps organize wiring, shields conductors from physical damage, and supports access for future inspection or replacement.
Also called: Electrical conduit
A Continuity Test is an electrical check that determines whether a complete, low-resistance path exists between two points in a circuit. A meter or dedicated tester sends a small test signal through the path and indicates continuity when the connection is complete. The result helps identify open wires, loose connections, broken conductors, or closed switches.
Also called: Continuity check
Direct-Burial Cable is an electrical cable built with insulation and an outer jacket that allow approved installation in soil. The cable carries power to outdoor equipment, detached structures, lighting, and other locations where wiring must pass underground. Its construction provides protection from moisture and contact with surrounding soil when installed as specified.
Also called: Underground cable
Disconnect Switch is a manually operated device that separates electrical equipment from its power supply. The switch provides a clear way to shut off power during service, inspection, or equipment replacement. A disconnect may serve a building, a panel, or a dedicated load such as an air-conditioning system or motor.
Also called: Electrical disconnect
Electrical grounding is a protective connection between an electrical system and the earth or another approved reference point. The connection gives unwanted electrical current a controlled path during a fault. Grounding also helps stabilize system voltage and supports protective devices that interrupt power when a dangerous fault develops.
Also called: Grounding
Electrical Load is the amount of power that connected devices and equipment draw from an electrical system during operation. The load changes as equipment starts, stops, or changes settings. Electricians assess the expected load to select suitable service capacity, conductors, panel equipment, and overcurrent protection for a building.
Also called: Power load
An electrical meter is a device that measures the electricity entering a building from the utility service. The meter records energy use for billing and helps identify the service capacity supplied to the property. It connects the utility conductors with the building’s service equipment, usually near the service entrance.
Also called: Electric meter
A Ground-Fault Circuit Interrupter is a protective electrical device that monitors current flowing through a circuit and quickly disconnects power when some current takes an unintended path to ground. A GFCI helps reduce shock risk in damp locations, outdoor areas, kitchens, bathrooms, garages, and other spaces where people may contact grounded surfaces.
Also called: GFCI
Junction Box is an enclosed electrical box that houses wire connections, splices, and branch points. The enclosure protects conductors from physical damage and keeps connections accessible for inspection or repair. Junction boxes may be installed in walls, ceilings, equipment areas, or exposed locations, depending on the wiring system and installation requirements.
Also called: Electrical junction box
Line Voltage is the electrical potential supplied by a power source to a circuit or device. It describes the voltage present on energized conductors before equipment uses that power. Electricians compare line voltage with equipment ratings to identify compatible connections, trace faults, and assess whether a circuit receives the expected supply.
Also called: Mains voltage
A Load Center is an electrical enclosure that receives power from a service entrance and distributes it through branch circuits. It contains circuit breakers, a busbar, neutral connections, and grounding connections. In homes, a load center is commonly called an electrical panel, although panel design and capacity vary by installation.
Also called: Breaker panel
Lug is a metal connector that secures an electrical conductor to a terminal, busbar, breaker, or other connection point. A lug uses a clamping screw, set screw, or compression method to hold the conductor firmly. In an electrical panel, the lug transfers current between the conductor and the connected component.
Also called: Electrical lug
A multimeter is a handheld electrical test instrument that measures voltage, current, and resistance. Many models also check continuity and other circuit conditions. Electricians use a multimeter to observe electrical values at conductors, terminals, outlets, switches, and equipment. The readings help identify open circuits, unwanted resistance, missing voltage, or energized components.
Also called: Volt-ohm meter, VOM
A neutral wire is a current-carrying conductor that provides the return path from a connected load to the electrical source in many alternating-current circuits. The neutral usually connects to the grounded conductor at the service equipment. It helps complete the circuit and supports the intended voltage between the ungrounded conductor and the neutral.
Also called: Neutral conductor
Overcurrent Protection is a system of devices and conductors that limits current when a circuit carries more electricity than its design allows. A circuit breaker or fuse opens the circuit during an overload or short circuit. This action helps protect wiring and connected equipment from damage caused by excessive current.
Also called: Overcurrent device
Photocell is a light-sensing electrical control that changes a circuit’s operation when surrounding light levels shift. In outdoor lighting, the device commonly turns fixtures on as daylight fades and off as daylight returns. A photocell helps automate lighting without requiring a person to operate a wall switch or timer.
Also called: Photoelectric sensor
A receptacle is a wiring device that provides a connection point for electrical equipment through a plug. Also called an outlet, it connects to circuit conductors and may include grounding, protective features, or multiple connection points. Receptacles serve appliances, equipment, and general-use devices in commercial and residential electrical systems.
Also called: Electrical outlet, Wall outlet
Service Entrance is the point where electrical power enters a building from the utility system and connects to the building’s electrical equipment. It includes the conductors, fittings, disconnecting equipment, and other components that carry and control incoming power before electricity moves through branch circuits serving lights, outlets, appliances, and equipment.
Also called: Electrical service entrance
Short Circuit is an unintended electrical connection that creates a low-resistance path between points with different voltage. The path allows current to rise sharply, which can trip a circuit breaker, damage wiring, or create heat. A short circuit commonly results from damaged insulation, loose conductors, moisture, or a failed electrical component.
Also called: Electrical short
Single-Phase Power is an electrical supply method that delivers alternating current through a single voltage waveform for equipment and circuits. The system commonly serves lighting, receptacles, office equipment, and other moderate electrical loads. Its design suits many commercial spaces, but larger motors and high-demand equipment may require three-phase power.
Also called: Single-phase electricity
A Surge Protector is a device that limits brief voltage increases and redirects excess electrical energy away from connected equipment. Surge protectors commonly connect at receptacles or within electrical panels. Panel-mounted protection helps cover circuits throughout a building, while a plug-in device protects equipment connected at that location.
Also called: Surge suppressor
A switch loop is a wiring method that sends power to a wall switch and returns switched power to a light fixture. The switch controls the fixture by interrupting the hot conductor. This arrangement commonly places the cable connection at the light box, while the switch operates from a remote location.
Also called: Switch leg
Three-Phase Power is an electrical distribution method that uses three alternating voltage waves with matched frequency and offset timing. The arrangement delivers a steadier flow of energy for motors and larger commercial equipment. It can support substantial electrical loads with balanced operation across the system when the equipment and wiring are properly designed.
Also called: Three-phase electricity
A Transfer Switch is a switching device that moves electrical loads between a normal utility supply and an alternate source, such as a standby generator. The device helps prevent both sources from feeding the same circuit at once. Transfer switches may operate manually or automatically, depending on the equipment and installation design.
Also called: Automatic transfer switch
Trenching is the process of creating a narrow excavation for placing underground electrical conductors, conduit, or related infrastructure. The work includes planning the route, opening the ground, preparing the excavation, installing the electrical pathway, and restoring the surface. Trenching connects an electrical system to equipment or structures that cannot be served through exposed wiring.
Also called: Utility trenching
An underwater pool light is a sealed lighting fixture designed for installation beneath the waterline of a swimming pool or spa. Its design separates electrical connections from pool water through sealed construction and suitable installation methods.
Also called: Pool light
Voltage Drop is the reduction in electrical pressure that occurs as current travels through a conductor, connection, or circuit component. The reduction results from the resistance of the path. Excessive voltage drop can cause lights to dim, motors to perform poorly, or equipment to operate unreliably even when the source voltage appears normal.
Also called: Voltage loss
Wire Gauge is a standardized way to describe a conductor’s thickness and current-carrying capacity. The gauge indicates the wire’s physical size, while the conductor material, insulation, installation method, and circuit load also affect proper selection. Smaller gauge numbers generally identify thicker conductors, which can carry more current than thinner conductors.
Also called: Wire size
