Plain definitions of 33 terms we use on the job in Santa Ana.
Term Index
Open any term below for a dedicated definition page.
AFCI is an arc-fault circuit interrupter, a protective device that monitors electrical current for patterns linked to unintended arcing. When the device detects a hazardous arc pattern, it opens the circuit to stop power flow. AFCI protection helps address faults that ordinary overcurrent protection may not detect quickly.
Also called: Arc-fault circuit interrupter
Amperage is the rate of electric charge flowing through a circuit or conductor. Electricians express amperage in amperes, commonly called amps. The value describes how much current a circuit carries at a given moment. Amperage helps determine whether a circuit, conductor, breaker, or electrical panel can support connected equipment safely.
Also called: Current, Electric current
An arc fault is an unintended electrical discharge that jumps across a gap between conductors or through damaged insulation. The discharge creates heat and may occur where wires are loose, worn, pinched, or improperly connected. Arc faults differ from ordinary current overloads because the damaging discharge can occur without exceeding a circuit breaker's normal current limit.
Also called: Electrical arc
Busbar is a solid metal conductor inside an electrical panel that distributes power to multiple circuit breakers or terminals. The busbar connects incoming electrical power with branch circuits while keeping connections organized. Its shape and position depend on the panel design, and separate busbars may serve hot, neutral, or grounding connections.
Also called: Bus bar
A capacitor is an electrical component that stores and releases energy in a circuit. In a ceiling fan, a capacitor helps create the phase shift needed for the motor to start and run. Its value affects motor behavior, including fan speed and torque. Capacitors may be found in fans, lighting equipment, air conditioners, and power supplies.
Circuit Tracer is a diagnostic tool that identifies which breaker, cable, or outlet belongs to a particular electrical circuit. The tool sends a detectable signal through a conductor, then a receiver follows that signal through a panel or building. Electricians use circuit tracers to map wiring and isolate circuits during troubleshooting.
Also called: Circuit finder
A conductor is a material or component that allows electric charge to move through a circuit. In building wiring, conductors are usually metal wires that carry current between the electrical panel, switches, outlets, and equipment. A conductor may serve as an ungrounded hot wire, a neutral wire, or a grounding path.
Also called: Electrical conductor
Conduit is a tube or channel that protects and routes electrical conductors between electrical boxes, panels, equipment, and other connection points. It may be made from metal or nonmetal materials. Conduit can also support organized wiring, simplify future conductor replacement, and shield wires from physical damage or environmental exposure.
Continuity is an unbroken electrical path that allows current to travel between connected points. Electricians check continuity to identify open circuits, loose connections, broken conductors, or incomplete paths. A continuity test normally uses a meter while power is off, helping confirm whether wiring, protective devices, and circuit parts connect as intended.
Also called: Electrical continuity
A Disconnect Switch is a manually operated device that opens an electrical circuit and separates equipment from its power source. The switch provides a visible, accessible means to shut off power during servicing or an emergency. In hot tub wiring, the disconnect switch is installed near the equipment so technicians can isolate the spa circuit.
Also called: Electrical disconnect
An electrical box is a protective enclosure that holds wire connections, switches, receptacles, or other electrical devices. The box shields connections from physical damage and keeps conductors contained. Electrical boxes come in forms suited to wall, ceiling, surface-mounted, indoor, and outdoor wiring. The correct box supports a secure, accessible installation.
Also called: Junction box
Electrical Load is the amount of electrical power that connected equipment draws from a circuit or electrical system during operation. The load depends on the equipment’s power demand and whether several devices operate at the same time. Electricians use load information to match circuits, conductors, breakers, and panels to actual operating conditions.
Also called: Load
An electric meter is a device that records the electrical energy supplied to a property. The meter connects the utility service to the building’s electrical system and tracks consumption over time. Utility personnel use its readings for billing, while electricians inspect meter operation and incoming service during power outage troubleshooting.
Also called: Electrical meter
GFCI is a protective electrical device that monitors current flowing through a circuit and disconnects power when it detects an imbalance associated with current leaving the intended path. It helps reduce shock risk in damp areas by interrupting power quickly, while circuit breakers primarily protect wiring from overloads and short circuits.
Also called: Ground-fault circuit interrupter
A ground fault is an unintended electrical connection between an energized conductor and a grounded surface, equipment enclosure, or grounding path. The connection allows current to leave its planned circuit route. Ground faults may result from damaged insulation, moisture, loose wiring, or faulty equipment, and protective devices can interrupt power when they detect the condition.
Also called: Earth fault
A grounding electrode is a conductive object, such as a metal water pipe or grounding rod, that connects an electrical system to the earth. The electrode provides a path for electrical energy to disperse into the soil during certain fault or surge conditions. It forms part of the grounding electrode system.
Also called: Ground electrode
Kilowatt is a unit of electrical power that describes how quickly equipment uses or produces energy. A kilowatt helps express the capacity of a generator, appliance, or electrical system in a consistent way. During generator installation, the kilowatt rating helps match available generator output with the electrical load a property may require.
Also called: kW
Line Voltage is the electrical potential supplied directly by a building’s power system to operate equipment and fixtures. It powers common devices such as recessed lights, switches, receptacles, and appliances. Line voltage differs from low voltage because it connects to the building’s branch circuit and requires wiring methods suited to that circuit.
Also called: Mains voltage
A Neutral Wire is a current-carrying conductor that normally completes the electrical path from a load back to the power source. In common wiring, the neutral connects with the grounded point of the electrical system and usually has a white or gray insulation color. It is different from the equipment grounding conductor.
Also called: Neutral conductor
An ohm is the unit used to express electrical resistance, which describes how strongly a material or component opposes current flow. Resistance affects the relationship between voltage and amperage in a circuit. Electricians use ohm readings to assess conductors, heating elements, coils, connections, and other parts during testing.
Also called: Ω
An overload is a condition in which connected electrical demand exceeds the safe capacity of a circuit, conductor, or protective device. The excess demand raises current flow and can heat wiring. A circuit breaker responds by opening the circuit to reduce the risk of equipment damage, insulation failure, or fire.
Also called: Electrical overload
Photocell is a light-sensitive electrical control that switches outdoor lighting on when surrounding light fades and off when daylight returns. The device uses a sensor to detect ambient brightness and send a control signal to a lighting circuit. It helps automate exterior fixtures without requiring manual operation at each switch.
Also called: Photoelectric sensor
A pigtail is a short length of electrical wire that joins multiple circuit conductors to a device terminal or another connection point. Electricians commonly use pigtails behind switches and receptacles when several wires must remain connected while one lead attaches to the device. The connection is enclosed inside the electrical box.
Also called: Pigtail wire
Polarity is the correct relationship between the energized, neutral, and grounding conductors in an electrical circuit. It identifies which conductor should carry voltage to a device and which should provide the return path. Correct polarity helps switches interrupt the energized conductor and allows receptacles, fixtures, and appliances to operate as designed.
Also called: Electrical polarity
Service Drop is the overhead electrical connection that carries utility power from a pole or other utility structure to a building’s service equipment. The service drop usually includes conductors, attachment hardware, and a connection point at the building. It ends where the utility’s service conductors connect with the customer-owned electrical system.
Also called: Electrical service drop
Single-Phase Power is an alternating-current electrical supply that uses one voltage waveform to deliver energy through a circuit. The supply commonly serves homes, apartments, and smaller commercial spaces. A circuit usually carries current through an energized conductor and returns it through a neutral conductor, supporting lighting, receptacles, appliances, and compatible equipment.
Also called: Single-phase electricity
A surge protector is an electrical protection device that limits brief increases in voltage and directs excess energy away from connected equipment. A whole-house surge protector installs at the electrical panel and helps protect circuits throughout a building. It does not regulate normal voltage or replace circuit breakers, grounding, or other protective devices.
Also called: Surge suppressor
A Transfer Switch is an electrical switching device that moves selected circuits between utility power and a standby generator. The switch helps prevent both sources from feeding the same circuit at once. Manual models require user action, while automatic models detect a utility outage and change the power source through a control system.
Also called: Generator transfer switch
A transformer is an electrical device that transfers alternating-current energy between circuits while changing voltage levels. Transformers use magnetic coupling between windings to raise voltage, lower voltage, or provide electrical isolation. The device supports safe and useful power distribution for equipment such as panels, chargers, lighting systems, and control circuits.
Voltage is the electrical potential difference that pushes electric charge through a circuit. Voltage provides the force that allows current to move between points with different electrical potential. A source such as a utility supply, battery, or generator creates this difference. Electricians measure voltage to assess circuit operation and electrical safety.
Also called: Electrical potential
Voltage Drop is the reduction in electrical pressure that occurs as current travels through a conductor and its connections. The reduction results from resistance in the circuit. Excessive voltage drop can leave equipment receiving less voltage than intended, causing dim lights, weak motor performance, nuisance operation, or unreliable device behavior.
Also called: Line drop
Wire Gauge is a standard way to describe a conductor’s diameter and current-carrying capacity. Gauge identifies the physical size of the metal inside an electrical wire. The gauge choice affects how much electrical current a conductor can carry, how easily it bends, and how well it suits a circuit’s design.
Also called: Wire size
A Wire Nut is a twist-on connector that joins two or more electrical conductors inside an insulated cap. The connector grips stripped wire ends through an internal spring or threaded design. Wire nuts come in sizes and colors suited to different conductor combinations, so the connector must match the wiring being joined.
Also called: Twist-on wire connector
