Plain definitions of 34 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 monitors electrical current for patterns linked to unintended arcing and disconnects power when those patterns appear. AFCIs help reduce fire risk from damaged, loose, or deteriorated wiring. They may be installed as circuit breakers or receptacles, depending on the electrical system.
Also called: AFCI
Backstab connection is a wiring method that holds a stripped conductor in a spring-loaded opening on the back of an outlet or switch. The connection avoids wrapping wire around a terminal screw. It can provide a compact installation, but a loose spring contact may cause intermittent operation, heat, or arcing when the conductor does not remain secure.
Also called: Back wiring
Ballast is an electrical component that regulates current in certain lighting systems and helps a lamp start and operate correctly. Traditional fluorescent fixtures use ballasts to control the arc through the tube. Ballasts may be magnetic or electronic, while many LED fixtures use a separate driver for comparable current control.
Also called: Light ballast
Breaker trip is the automatic opening of a circuit breaker when electrical current exceeds a safe operating level or a fault occurs. The interruption stops power through the affected circuit and helps limit damage to wiring and connected equipment. A trip may result from an overload, short circuit, or ground fault.
Also called: Tripped breaker
Busbar is a conductive metal strip or bar inside electrical equipment that distributes power to multiple circuits. A busbar provides a common electrical connection for circuit breakers, disconnects, or other components. Its size, material, insulation, and connection points must suit the panel design and the electrical load served.
Also called: Bus bar
A capacitor is an electrical component that stores and releases energy in a circuit. In a ceiling fan, the capacitor helps create the phase shift needed for the motor to start and run. Its electrical value affects motor behavior, fan speed, and torque. A failed capacitor can leave a fan humming, slow, or unable to start.
Also called: Fan capacitor
A ceiling fan downrod is a rigid tube that connects a ceiling fan motor to its mounting bracket and lowers the fan from the ceiling. The added distance helps position the blades in open air when a ceiling is high, sloped, or obstructed. Downrods also provide a stable path for wiring between the fan and ceiling box.
Also called: Fan downrod
A circuit breaker is an electrical switching device that interrupts current when a circuit develops an unsafe condition, such as excessive load or a short. The breaker protects wiring and connected equipment by opening the circuit. After the cause is corrected, the breaker can usually be reset, unless damage or a continuing fault prevents safe operation.
Also called: Breaker
Circuit overload is a condition in which connected electrical devices draw more current than a circuit can safely carry. The excess demand can heat conductors and cause the circuit breaker to trip. Overload usually results from too many high-demand devices sharing one circuit, not from a fault between energized conductors.
Also called: Overloaded circuit
Conduit is a protective pathway that houses electrical wires and cables. It may be made from metal or nonmetallic material and can run through walls, ceilings, floors, or outdoor areas. Conduit helps organize conductors, shield them from physical damage, and support orderly routing during new construction or wiring changes.
Also called: Electrical conduit
A dimmer switch is a wall control that adjusts the electrical power delivered to a compatible light source, allowing you to change light output from brighter to softer. Unlike a standard switch, which provides simple on-or-off control, a dimmer supports adjustable illumination for tasks, comfort, and room atmosphere when the lighting system supports dimming.
Also called: Light dimmer
Electrical grounding is the intentional connection of electrical equipment and circuits to the earth or a grounding system. The connection gives unwanted electrical current a controlled path away from exposed metal and toward the source. Grounding supports fault clearing, limits voltage on equipment enclosures, and helps keep a wiring system stable during normal operation.
Also called: Grounding
An electrical short is a fault that creates an unintended low-resistance path for current between conductors or between a conductor and ground. The sudden current increase can trip a circuit breaker, damage wiring, produce heat, or interrupt power. A short usually points to damaged insulation, loose connections, moisture, or failed equipment.
Also called: Short circuit
An EV charger connector is the plug and matching vehicle inlet interface that transfers electrical power between an electric vehicle supply system and an electric vehicle. The connector carries charging current through designed contacts and may also support communication between the charger and vehicle. Its shape and contact arrangement determine compatibility.
Also called: EV charging connector
A four-way switch is an electrical control that changes the path of current between traveler wires in a multi-location lighting circuit. It works with three-way switches to operate one light from several locations. Unlike a standard switch, a four-way switch does not serve as the end control in that circuit.
Also called: 4-way switch
A GFCI outlet is a receptacle that monitors electrical current leaving and returning through a circuit. If the current becomes unbalanced, the outlet quickly interrupts power to reduce shock risk from a ground fault. GFCI outlets commonly serve areas where electricity may contact moisture, including kitchens, bathrooms, garages, laundry areas, and outdoor locations.
Also called: GFI outlet, Ground-fault circuit interrupter outlet
Ground fault is an unintended electrical connection between an energized conductor and grounded metal, equipment, or earth. This path allows current to leave its intended circuit route. A ground fault can cause a circuit interrupter to open the circuit and may indicate damaged insulation, moisture intrusion, or an incorrect connection that requires diagnostic testing.
Also called: Ground fault condition
Junction box is an enclosed electrical container that protects and organizes wire connections where circuits meet, split, or change direction. The box keeps splices accessible for inspection and service while shielding connections from contact, impact, and surrounding materials. Junction boxes may be made from metal or nonmetallic material, depending on the wiring system.
Also called: Electrical junction box
An LED driver is an electronic power supply that converts incoming electrical power into the controlled voltage or current an LED light source needs. The driver regulates that power to support stable light output and protect the LEDs from electrical changes. Some LED drivers are built into fixtures, while others are separate components.
Also called: LED power supply
Load calculation is an engineering assessment of the electrical demand a property or circuit may place on a power system. The assessment considers equipment ratings, expected operation, and demand patterns. Electricians use the result to determine whether an electrical panel, service, feeder, or circuit can support connected equipment without exceeding its intended capacity.
Also called: Electrical load calculation
Neutral wire is the grounded conductor that carries current back to the electrical panel after power flows through a device or load. It completes many household circuits and normally stays near ground potential. A neutral wire is not the same as an equipment grounding conductor, which serves a different protective function.
Also called: Neutral conductor
NM cable is a factory-assembled wiring cable with insulated conductors enclosed in a nonmetallic outer jacket. The cable carries electrical current through branch circuits inside dry, protected building spaces. Its jacket keeps the conductors together and helps identify the cable as a finished wiring assembly for residential electrical work.
Also called: Nonmetallic cable, Romex
Photocell is a light-sensitive electrical control that switches a lighting circuit on when surrounding light becomes low and switches it off when daylight returns. A photocell helps outdoor fixtures operate automatically without a manual switch. It is commonly used for security lights, pathway fixtures, wall packs, parking-area lighting, and other dusk-to-dawn applications.
Also called: Light sensor, Photoelectric sensor
A receptacle is a wiring device that provides contact points for a plug and connects an electrical appliance to a branch circuit. The device may include grounding contact points, protective features, or multiple plug locations. In everyday language, people often call a receptacle an outlet, although outlet can describe other points where electrical energy leaves a circuit.
Also called: Electrical outlet, Power outlet
Service entrance is the point and equipment where electrical power enters a building from the utility system and connects to the building’s wiring. The term can describe the service conductors, meter equipment, disconnecting means, and related components that carry power to the main electrical panel. It does not mean every circuit inside the building.
Also called: Electrical service entrance
A smart switch is a wall-mounted control that operates lighting or other connected loads and communicates with a home network, hub, or voice assistant. Unlike a standard switch, a smart switch can support remote control, schedules, scenes, or automation. Many models also retain physical button control for local operation.
Also called: Wi-Fi light switch
A Surge protector is a device that limits excess electrical voltage and diverts damaging energy away from connected equipment. A plug-in model protects selected devices at an outlet. A whole-home model connects at the electrical panel and helps protect multiple circuits from voltage surges caused by utility activity, lightning, or switching loads.
Also called: Surge suppressor
Thermal imaging is a diagnostic method that creates a visual map of surface heat patterns using infrared radiation. Electricians compare temperatures across similar components to identify unusual heating linked to loose connections, excessive load, damaged conductors, or failing equipment. The scan supports troubleshooting but does not replace electrical testing.
Also called: Infrared inspection
A three-way switch is a wall control that lets you operate one light or fixture from multiple locations. The switch has a common terminal and traveler terminals that route power along different paths. Three-way switches are common in hallways, stairways, and rooms with entrances on opposite sides.
Also called: 3-way switch
A transformer is an electrical device that changes alternating-current voltage from one level to another through electromagnetic induction. Transformers can raise voltage, lower voltage, or provide electrical isolation between circuits. In lighting installation, a transformer may adapt building power for low-voltage fixtures, landscape lights, or specialized lighting equipment.
Also called: Lighting transformer
Voltage drop is the reduction in electrical potential that occurs as current travels through a conductor or connection. It reflects resistance in the circuit and can leave equipment receiving less voltage than the source provides. Technicians assess it under load to locate wiring, connection, or circuit problems.
Also called: Voltage loss
Wire gauge is a standardized system for describing a conductor's diameter and current-carrying capacity. Gauge numbers correspond to wire size, with lower numbers generally identifying thicker conductors. Electricians select the gauge based on the circuit load, conductor material, installation conditions, and required voltage performance.
Also called: Electrical wire size
A wire nut is an insulated twist-on connector that joins compatible electrical conductors inside an electrical box or enclosure. The connector grips the prepared wire ends through internal threads or a spring. Wire nuts come in different sizes and colors, so the connector must match the wire type, size, and number of conductors.
Also called: Wire connector
A wiring diagram is a visual plan that shows how electrical conductors, devices, terminals, and power sources connect within a system. Symbols and labeled lines represent the physical or functional relationships between components. Electricians use the diagram to trace circuits, install equipment, verify connections, and diagnose faults in residential wiring.
Also called: Electrical wiring diagram
