Plain definitions of 35 terms we use on the job in Fort Wayne.
Term Index
Open any term below for a dedicated definition page.
An Arc-Fault Circuit Interrupter is a protective device that detects the electrical pattern of arcing and opens a circuit before a damaged connection can create a fire hazard. An AFCI may be built into a circuit breaker or installed as an outlet device. It protects against unwanted arcing that ordinary overcurrent protection may not detect.
Also called: AFCI
Backfeed is the unintended flow of electrical power from a secondary source into wiring that normally receives power from the utility. A generator, inverter, or another energized circuit can create this condition when circuits connect incorrectly. Backfeed can energize utility lines or equipment that workers expect to be de-energized, creating a serious electrical hazard.
Also called: Electrical Backfeed
A Branch Circuit is a wiring path that carries electricity from a service panel to outlets, lights, appliances, or other connected loads. The circuit includes the conductors, protective device, and connection points that serve those loads. Its design must match the connected equipment and the conditions of the installation.
Busbar is a conductive metal bar or strip that distributes electrical power within equipment such as a panelboard or switchgear. A busbar connects incoming power with branch circuits through an organized, low-resistance path. Insulating supports, barriers, or enclosure parts keep the energized conductor positioned and separated from other components.
Also called: Bus Bar
A capacitor is an electrical component that stores and releases energy within a circuit. In ceiling fans, a capacitor helps create the phase shift needed for the motor to start and run. Its capacitance and voltage rating must match the motor’s design. A failed capacitor can cause weak operation, humming, or failure to start.
Also called: Motor Capacitor
A conduit is a protective raceway that contains and routes electrical conductors. Conduit may be made from metal or nonmetallic material, depending on the installation. It shields wiring from physical damage, moisture, heat, and other site conditions while keeping conductors organized and accessible for repair or replacement.
Also called: Electrical Conduit
A continuity test is an electrical check that shows whether a complete path exists between two points in a circuit. A meter sends a small test signal through the selected path and detects low resistance when the path is intact. A high reading indicates an open connection, damaged conductor, switch, fuse, or component.
Also called: Continuity Check
Current is the movement of electric charge through a conductor, such as a wire or circuit path. The amount of current depends on the electrical pressure and the resistance in that path. Electricians check current to identify overloads, faulty components, loose connections, and other conditions that affect circuit operation.
Also called: Electrical Current
Disconnect Switch is a manually operated device that separates electrical power from equipment or a circuit. The switch provides a clear means to isolate connected wiring during service, inspection, or an emergency. A disconnect may be installed near equipment, within sight of it, or as part of an electrical enclosure.
Also called: Safety Disconnect
Electrical load is the amount of power that connected equipment draws from an electrical system at a given time. The load changes as devices start, stop, or operate at different settings. Electricians assess load to match circuits, conductors, breakers, and service capacity with the demands of appliances, lighting, heating equipment, and other electrical devices.
Also called: Load Demand
An electrical meter is a testing instrument that measures electrical values in a circuit, such as voltage, current, or resistance. Technicians select a measurement mode and connect the meter leads at appropriate points. The resulting reading helps identify energized conductors, open paths, excessive resistance, and other conditions during inspection or troubleshooting.
Also called: Electric Meter
Electrical shock is the physical effect of electric current passing through the body. The current may cause pain, muscle reaction, burns, or disruption of normal body function. Contact with energized wiring, damaged equipment, faulty outlets, or an unintended path to ground can produce a shock, even when the visible damage appears minor.
Also called: Electric Shock
Ground Fault is an unintended electrical connection that lets current leave its intended path and flow toward grounded surfaces or equipment. The condition can create shock and fire hazards, so protective devices such as GFCI outlets monitor the circuit and disconnect power when they detect an unsafe imbalance.
Also called: Grounding Fault
A grounding electrode is a conductive object that connects an electrical system to the earth. The connection provides a path for certain electrical energy during faults, surges, or system events. Common examples include metal water piping, concrete-encased reinforcing steel, and grounding electrodes installed specifically for that purpose.
Also called: Ground Rod
A junction box is an enclosed electrical box that protects and contains wire connections where conductors join, branch, or change direction. The box keeps splices accessible for inspection and repair. It may be made from metal or nonmetallic material and can serve lighting, receptacle, appliance, or other branch-circuit wiring.
Also called: Electrical Junction Box
Line Voltage is the electrical potential supplied by a building’s wiring system to operate equipment and fixtures. It is the power present at a circuit before a device changes, controls, or uses that energy. Light fixtures, switches, receptacles, and circuit breakers interact with line voltage during normal operation.
Also called: Mains Voltage
A load center is an electrical enclosure that distributes power from the service entrance to branch circuits throughout a building. It contains circuit breakers, a busbar, and neutral and grounding connections. In many homes, people call the load center the electrical panel, although panel layouts and equipment ratings can vary.
Also called: Breaker Panel
Neutral Wire is a grounded conductor that carries electrical current back to the service equipment after current flows through a load. The neutral wire helps complete a 120-volt circuit in many household systems. It connects to the neutral bus in the electrical panel and normally remains near ground potential during proper operation.
Also called: Neutral Conductor
Ohm is the standard unit of electrical resistance. Resistance describes how strongly a material or component opposes electric current. A higher resistance allows less current under the same voltage, while a lower resistance allows more current. Electricians use ohms to assess conductors, heating elements, coils, switches, and suspected circuit faults.
Also called: Ohm Unit
Overload is a condition in which an electrical circuit carries more current than its wiring or protective device can safely handle. The excess current creates heat and may cause a circuit breaker to trip. An overload usually develops from connected equipment drawing too much power, not from a direct connection between conductors.
Also called: Circuit Overload
Photocell is a light-sensitive electrical control that turns an outdoor lighting circuit on at dusk and off at daylight. The device senses surrounding brightness through a photosensor, then signals a switch or control component. Photocells help automate landscape lights, security fixtures, wall packs, and other exterior lighting without daily manual operation.
Also called: Photoelectric Sensor
A pigtail is a short length of electrical wire that joins multiple conductors to a terminal, device, or grounding point. The pigtail connects within an electrical box, allowing the circuit conductors to continue while a receptacle, switch, or other device receives a separate connection. Electricians form pigtails with approved connectors and matching conductors.
Also called: Electrical Pigtail
Romex is a common trade name for nonmetallic-sheathed cable used in residential wiring. The cable contains insulated conductors and a grounding conductor inside a flexible plastic jacket. Electricians use it for branch circuits in walls, ceilings, and other protected spaces where the installation conditions suit nonmetallic cable.
Also called: NM Cable, Nonmetallic Cable
A service entrance is the part of an electrical system that connects utility power to a building's main disconnect and service equipment. It includes the conductors, raceway, meter connection, grounding connection, and related equipment that carry power into the property. The service entrance establishes the point where utility supply becomes the building's electrical service.
Also called: Electrical Service Entrance
A short circuit is an unintended low-resistance path between electrical conductors, allowing current to move outside its normal route. The sudden rise in current can trip a circuit breaker, blow a fuse, damage wiring, or create heat. A short circuit may result from damaged insulation, loose connections, moisture, or a failed electrical component.
Also called: Electrical Short
A single-pole switch is a wall-mounted control that opens or closes one electrical circuit from one location. The switch commonly controls a light fixture, exhaust fan, or other load. Its toggle has on and off positions, and the device is designed for circuits where one switching point controls the connected equipment.
Also called: Single-Pole Light Switch
A surge protector is a device that limits excessive voltage and redirects transient electrical energy away from connected equipment. A whole-house surge protector connects at the electrical panel, where it can help protect multiple circuits at once. Its protection depends on correct wiring, grounding, and the device’s ability to respond to voltage changes.
Also called: Surge Suppressor
A tamper-resistant outlet is a receptacle with internal shutters that block access to the energized contacts when an object enters only one slot. The shutters open when a plug applies balanced pressure to both slots. This design helps prevent accidental contact with electrical parts while preserving normal plug operation in homes and other occupied spaces.
Also called: TR Outlet
Thermal Imaging is a diagnostic method that displays surface temperature patterns as an image. An infrared camera detects heat emitted by electrical equipment and shows warmer areas for inspection. Electricians use these patterns to locate possible loose connections, overloaded components, damaged conductors, or uneven loading without removing every cover.
Also called: Infrared Inspection
A three-way switch is a wall switch arrangement that controls one light or fixture from two separate locations. Each switch works with the other through traveler wires, so either location can change the light's state. This setup is common in hallways, stairways, and rooms with more than one entrance.
Also called: 3-Way Switch
A transfer switch is an electrical device that changes a building’s power source between utility service and a standby generator. The switch directs electricity to selected circuits or the whole electrical system, while preventing the two sources from operating together. This arrangement supports generator operation without manual cable connections or unintended backfeed.
Also called: Generator Transfer Switch
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. A load may receive less voltage than the source provides, which can affect equipment operation, lighting performance, and troubleshooting results.
Also called: Voltage Loss
Voltage Tester is a handheld electrical testing tool that indicates whether voltage is present in a conductor, outlet, switch, or other circuit point. Depending on its design, a voltage tester may provide a simple energized indication or display a measured voltage value. It helps identify circuit conditions during electrical inspection and troubleshooting.
Also called: Non-Contact Voltage Tester
Wire gauge is a standardized way to describe a conductor's diameter and current-carrying capacity. The gauge designation helps electricians select wire that matches a circuit's electrical load, installation method, and acceptable voltage drop. Smaller gauge numbers generally identify thicker conductors, while larger gauge numbers generally identify thinner conductors.
Also called: American Wire Gauge, AWG
Wire Nut is a twist-on connector that joins electrical conductors inside a junction box or enclosure. The connector has an insulated outer shell and an internal spring or threaded insert that grips the prepared wire ends. Wire nuts come in different sizes and colors, so the connector must match the conductors and connection.
Also called: Twist-On Wire Connector
