Electrical Terms: A Glossary of Industry Lingo + Detailed Definitions

Amperage / Ampere / Amp

Amperage refers to the quantity of electrical current flowing through a circuit, measured in amperes or “amps.” Electrical devices require a specific amperage to operate, which is usually listed on their nameplates or data labels.

Voltage, Volts

Voltage is the electrical pressure that pushes current through a circuit. One volt is enough pressure to move one amp of current through one ohm of resistance.

Ohm

An ohm is a unit that measures electrical resistance in a circuit. One volt will push one amp of current through a resistance of one ohm.

Circuit

A circuit is a closed loop that allows electricity to flow from the power source to the load (e.g., equipment) and back. It includes a hot wire (carrying current), a neutral wire (returning current), and a ground wire (for safety). Circuits are rated by the amount of current they can safely handle.

Outlet / Receptacle Outlet

A receptacle outlet is the point where you plug in devices to access electricity from a branch circuit. The outlet is the connection at the back, while the receptacle is the visible front part that receives the plug. Receptacles can be simplex (one plug), duplex (two), or triplex (three), and planners must account for the number of outlets, not receptacles, when following code requirements.

Hot Conductor

The hot conductor is the wire that carries electrical current from the power source to a device or outlet. It always needs a neutral conductor to complete the circuit and return the current to the source.

Neutral Conductor

The neutral conductor carries current back to the power source in an electrical circuit, completing the loop started by the hot conductor. It plays a crucial role in maintaining balanced and safe power flow.

Ground Conductor

A ground conductor is a wire that connects electrical systems to the earth, providing a safe path for excess electricity in case of a short circuit or equipment failure. It carries no current during normal operation and helps prevent electrical shock by maintaining a zero-volt potential.

Load

A load refers to the amount of electrical power a device or circuit uses. It’s typically measured in amps, but sometimes expressed in watts.

Wattage, Watts

Wattage measures the power an electrical device uses and is calculated by multiplying voltage by amperage. For example, a 120-volt device drawing 2 amps uses 240 watts

Power Outage

A power outage is a sudden loss of electricity caused by utility failures or a tripped circuit breaker. Devices without backup power, such as a UPS, may lose unsaved data during an outage.

Short Circuit

A short circuit happens when a hot wire touches a neutral or ground wire, causing a sudden surge of electricity. This can damage the circuit and usually trips a breaker for safety.

Junction Box

A junction box is a protective enclosure where electrical wires are connected or spliced. It helps organize wiring safely, often using wire nuts to connect conductors inside the box.

Wire Gauge

Wire gauge indicates the thickness of a wire; the smaller the number, the thicker the wire. In modular furniture systems, wire gauge alone doesn’t determine how much current it can handle. Full testing and UL listing are needed for safety.

Circuit Breaker

A circuit breaker is a protective device that automatically shuts off power when a circuit is overloaded. Most branch circuits use 15- or 20-amp breakers, and NEC guidelines recommend not exceeding 80% of the breaker’s rated load to avoid unnecessary trips.

Connector / Terminal

Connectors and terminals are devices used to join or end electrical conductors safely. Their ampacity ratings determine the current-carrying capacity of a system, which can sometimes override the gauge of the wire itself.

Conductor

In electrical systems, a conductor is any component that carries current, not just the wire itself. It includes wiring, connectors, breakers, and any other parts that help form a complete path for electricity. All conductors must be UL-listed for safety compliance.

Conduit

A conduit is a protective tubing, which is either metal or non-metallic, rigid or flexible. It’s used to house and route electrical wires. It shields the wires from physical damage and can help meet code requirements in commercial and residential applications.

Ballast

A ballast regulates the flow of electrical current to fluorescent lamps to ensure safe and efficient operation. Ballasts can be magnetic or electronic, with electronic versions offering better energy efficiency and performance.

Surge Protector / Spike Protector

A surge protector guards against sudden spikes in voltage that can damage electronics. It works by diverting excess voltage caused by events like lightning or large equipment switching on and off.

UL Listed, ULc, CSA, ETL

UL Listed means a product has been tested and meets safety standards set by Underwriters Laboratories in the U.S. ULc and CSA are similar Canadian certifications, while ETL is another recognized testing lab in North America. These marks confirm that electrical products are safe and approved for use.

Electrical Test Laboratories

This term refers to accredited testing organizations like UL, ULc, CSA, and ETL that evaluate and certify electrical equipment for safety and compliance. Products bearing these marks meet rigorous standards and are approved for installation in regulated environments.

Local Electrical Codes

Local electrical codes are regulations set by municipalities or states that govern how electrical systems must be installed for safety and compliance. While most follow the National Electrical Code (NEC), some cities like Chicago or New York have stricter rules. Always confirm local requirements before starting a project.

Inspector

An electrical inspector is a professional authorized by a local government agency to verify that electrical installations meet safety codes. All branch circuits in a building must be approved by such an inspector before being put into service.

Isolated Ground

An isolated ground is a grounding method used to protect sensitive electronics from electrical noise. It involves a separate path to ground, insulated from the regular building grounding system.

National Electrical Code (NEC)

The NEC is a set of nationally recognized standards for safe electrical design, installation, and inspection. Local authorities may enforce NEC rules alone or add more restrictive local codes.

Polarized Plug / Grounded Plug / 3-Prong Plug

These plugs are designed to fit into receptacles in only one orientation for safety. The third prong (ground) helps protect users from shock by providing a safe path for fault current. All Haworth receptacles are compatible with polarized, grounded plugs.

Branch Circuit

A branch circuit is the portion of an electrical system that extends from the final overcurrent protection device (like a circuit breaker) to the outlets or devices being powered. Each branch circuit must be inspected and UL-listed to ensure safety.

Dedicated Circuit

A dedicated circuit is wired to serve only one piece of equipment, ensuring that the full amperage of the circuit is available for that device. Common for copiers, space heaters, or kitchen appliances to prevent overloads.

Multi-Wire Branch Circuit (MWBC)

A MWBC uses two hot wires of opposite phases that share a neutral wire. This setup allows for more efficient use of wiring and is often used in modular furniture systems to power two circuits with fewer conductors. However, it requires careful load balancing and simultaneous disconnecting of breakers.

GFCI (Ground-Fault Circuit Interrupter)

A GFCI detects imbalances between hot and neutral wires, which could indicate current leaking through a person to ground. If detected, it shuts off power immediately to prevent electrocution. Required in wet areas like kitchens and bathrooms.

AFCI (Arc-Fault Circuit Interrupter)

An AFCI detects electrical arcs that could start fires, which are often caused by damaged wires or loose connections. It trips the circuit when unsafe arcing is detected and is required in many residential spaces by the NEC.

Ground Loop

A ground loop occurs when there are multiple paths to ground, causing interference or electrical noise in sensitive equipment. It’s a common issue in data centers and audiovisual systems, and proper grounding design helps prevent it.

Load Balancing

Load balancing refers to evenly distributing electrical demand across available circuits or phases in a panel. This helps prevent overloads and ensures efficient operation in systems using multiple branch circuits or MWBCs.

Electrical Phases (Single vs. Three Phase)

Single-phase systems use one alternating current path, typical in residential settings. Three-phase systems have three alternating currents offset in time, common in commercial and industrial buildings due to their efficiency in handling higher loads.

Raceway

A raceway is any enclosed channel (such as conduit or cable tray) used to route and protect electrical wiring. Modular raceways in furniture systems allow easy access for reconfiguration while maintaining code compliance.

Busway / Busbar

A busway is a modular track system that distributes power using enclosed conductive bars (busbars). It allows flexible placement of power taps and is common in open office environments and commercial ceilings. Requires UL listing for branch circuits.

Power Distribution Unit (PDU)

A PDU is a device that distributes electric power to multiple equipment outlets, often used in server rooms or office furniture systems. It may include circuit breakers, surge protection, and metering.

Transformer

A transformer changes voltage levels in an electrical system. In commercial interiors, transformers are used to step down 277 volts (for lighting) to 120 volts (for outlets) or to isolate different systems for safety and noise reduction.

Watt-Hour / Kilowatt-Hour (kWh)

A watt-hour is a measure of energy consumption equal to one watt used for one hour. A kilowatt-hour is 1,000 watt-hours and is the standard unit for billing electricity usage.

Flexible Power Whip / Modular Power Whip

A power whip is a flexible electrical connection from a building’s junction box to a modular furniture system. It provides power into a modular distribution system and must be UL-listed for branch circuit use.

Modular Electrical System / Modular Power System

A modular electrical system allows plug-and-play connections for power in office furniture or walls. Components like power whips, distribution harnesses, and receptacles snap together, offering flexibility while requiring careful UL compliance.

Cable Tray / Wireway / Panduit

Cable trays and wireways organize and route multiple conductors safely through ceilings or under floors. “Panduit” is a brand often used generically to refer to surface-mounted cable management systems.

Nameplate Rating

A device’s nameplate rating shows its electrical requirements, including voltage, amperage, and wattage. These values must be considered when designing circuits and selecting compatible components.

Overcurrent Protection Device (OCPD)

An OCPD is a device like a fuse or circuit breaker that protects circuits from drawing more current than they can safely carry. It must be rated to match the weakest part of the circuit, usually the conductor or connector with the lowest ampacity.

Ampacity

Ampacity is the maximum amount of current a conductor or component can carry continuously without overheating. Factors like temperature, insulation, and enclosure type affect ampacity. UL testing ensures real-world safety ratings.

Voltage Drop

Voltage drop is the reduction in voltage as electricity travels through a conductor due to resistance. Excessive voltage drop can cause equipment to malfunction and must be minimized by using larger wires or shorter runs.

Selective Coordination

Selective coordination ensures that only the closest overcurrent protection device to a fault will trip, leaving the rest of the system operational. It’s critical in mission-critical environments like hospitals and data centers.

Panelboard / Load Center

A panelboard (or load center) is where incoming power is divided into branch circuits, each protected by a breaker. It distributes electricity throughout a space and must be labeled and sized according to NEC requirements.

Arc Flash

An arc flash is a sudden, high-energy explosion caused by an electrical fault, which can result in fire or serious injury. Arc flash studies and proper PPE are required in commercial electrical work to reduce risk.

Harmonics

Harmonics are voltage or current distortions caused by nonlinear loads (like computers or LED drivers). They can overheat conductors and transformers if not managed with proper filtering or system design.

Voltage Sag / Surge / Transient

Voltage sags are short-term drops in voltage; surges are short-term increases. Both can damage equipment or cause malfunctions. Transients are extremely short, high-voltage spikes usually caused by switching or lightning.

Power Factor

Power factor is a measure of how efficiently electrical power is being used. A low power factor means more current is required for the same work, leading to increased utility charges and the need for correction using capacitors or filters.

Load Shedding

Load shedding is the practice of selectively shutting off non-critical electrical loads to prevent overload during peak demand or emergency situations. Used in both utility-level grids and building automation systems.

Building Automation System (BAS)

A BAS is a centralized control system that manages electrical, HVAC, lighting, and other building systems for efficiency and safety. It can automate load shedding, dimming, and energy monitoring based on real-time conditions.

UL 962 / UL 1286 / UL 183

These are UL standards for office furniture and modular wiring systems. UL 962 covers electrical components in office furniture, UL 1286 addresses panel systems, and UL 183 governs field-installed wiring systems. Compliance is required for branch circuit installations in commercial interiors.

Electrical Inspector Authority Having Jurisdiction (AHJ)

The AHJ is the local official (often an inspector) responsible for enforcing electrical codes and approving installations. Their interpretation of code determines what is permitted, even if a system is UL-listed.

Alligator Knob

A device used for operating tie sticks.

Baby Shoes

Small copper terminals designed for use with circuit-sized wiring.

Bible

The National Electrical Code book, relied on by electricians.

Broomsticks

Insulating phase spacers that prevent electrical phases from touching each other midspan.

Candy Grabbers

Lineman’s pliers, often used for gripping and twisting wires.

Cowboy

A conduit hanger for securing 1/2″ to 4″ rigid or EMT conduit to supports, struts, or surfaces, available with or without a bottom bolt and nut, and made by various manufacturers.

Dead Man

A multi-blade earth anchor that expands underground to support heavy loads via soil compression.

Eels

Flexible line hose used as temporary insulation on live wires.

Fish Bit

A flexible, long-shafted drill bit used for drawing wire through existing walls.

Gang Box

A portable storage chest for contractor tools at a construction site.

Hard Head

A heavy-duty lag bolt used for fastening.

Jacob’s Ladder

A portable rope ladder that can be repositioned easily.

Knee

A small strut angle bracket for mounting or support.

Lady Slippers

A term old-timers use for modern climbing gear.

Magic Smoke

The visible smoke released when an electrical component burns out due to a short.

Nutty Putty

A pliable sealing compound for insulating and sealing connections.

Old Man

An A-frame gin pole used for lifting transformers and other heavy equipment.

Pancake Box

A shallow, round electrical box for mounting ceiling fixtures, typically 1/2″ deep.

Rabbit

Leftover or scrap wire, especially copper, valued for recycling.

Sesame Hook

A resettable combination padlock that operates without a key.

Tie-stick

A tie-stick is a tool used to support and position electrical conductors safely

Toothpick

An extendable scaffold board that can be adjusted for length.

U Bangi

High-voltage (15 kV) rubber insulating line hose.

Walking Crab

A manual lever hoist or lift.

Zinc-It

A zinc-rich spray used to coat and protect metal surfaces from rust and corrosion.