ICC E3 key terms

Acceptable to the authority having jurisdiction. The term signals that the code official, not the installer, decides whether equipment or a method is permissible, and it may rest on listing, labeling, or field evaluation.

The organization, office, or individual responsible for enforcing code requirements or approving equipment, materials, installations, or procedures. Inspectors, fire marshals, and building officials commonly act as the AHJ for electrical work.

Equipment, materials, or services included in a published list by an organization concerned with product evaluation that maintains periodic inspection of production and states the item meets a designated standard.

Equipment or materials to which a label, symbol, or other identifying mark of a qualified testing organization has been attached, indicating compliance with appropriate standards or performance in a specified manner.

Nationally Recognized Testing Laboratory: a private organization recognized by OSHA to test and certify products to safety standards. UL, ETL, and CSA are common examples whose marks support the code's listing and labeling requirements.

The pre-construction examination of drawings, specifications, and calculations by the code official to verify compliance before a permit is issued. Reviewers check load calculations, one-line diagrams, device ratings, and grounding details.

Official authorization to begin work covered by the code. Electrical permits typically require submitted plans and fee payment, and work must match the approved documents or be revised through the jurisdiction.

Drawings revised to show the installation as actually constructed, including field changes from the permitted design. Reviewers and inspectors use them to confirm that deviations were approved and documented.

A document issued by the building official confirming a structure may be occupied for its intended use. Electrical final inspection and approval are typically prerequisites before it is granted.

On-site verification by the AHJ that installed work complies with the code and approved plans. Common stages include underground, rough-in, and final inspections, and cover work must be approved before concealment.

The maximum current, in amperes, a conductor can carry continuously under stated conditions of use without exceeding its temperature rating. It depends on conductor size, insulation, ambient temperature, and number of current-carrying conductors.

A load expected to operate at maximum current for three hours or more. Conductors and overcurrent devices serving continuous loads must be sized at 125 percent of the load unless the code states otherwise.

A load expected to operate at maximum current for less than three hours. It is added at its full calculated value, without the 125 percent multiplier applied to continuous loads.

The ratio of the maximum demand on a system to the total connected load. Applying demand factors permits smaller feeders and services because not all loads operate simultaneously at full value.

The sum of the rated capacities of all equipment and devices supplied by a system, before any demand factors are applied. It represents the worst-case total if everything ran at once.

A structured method of summing general lighting, receptacle, appliance, and motor loads, then applying demand factors, to determine the minimum feeder, service, and panelboard ratings for a building.

The conductors and equipment that deliver power from the serving utility to the wiring system of the premises. Service-entrance conductors, service equipment, and the service point define its boundaries.

All circuit conductors between the service equipment, source of a separately derived system, or other supply source and the final branch-circuit overcurrent device. Feeders supply panelboards rather than individual outlets.

The circuit conductors between the final overcurrent device protecting the circuit and the outlet or outlets it serves. Branch circuits supply the actual utilization equipment and receptacles.

A branch circuit with two or more ungrounded conductors having a voltage between them and a grounded conductor with equal voltage to each ungrounded conductor. It requires a common trip or handle-tied breakers and grouped conductors.

Any device, such as a fuse or circuit breaker, that automatically opens a circuit when current exceeds a set value. It protects conductors and equipment from overloads and short circuits.

A system or circuit conductor intentionally connected to earth, commonly the neutral. It carries return current under normal operation and is bonded to grounding at the service.

The conductive path installed to connect normally non-current-carrying metal parts of equipment together and to the system grounded conductor or grounding electrode conductor. It carries fault current to trip the overcurrent device.

The conductor that connects the grounding electrode system to the grounded conductor or equipment grounding conductor at the service or source. It provides the earth connection for the electrical system.

A conductive object such as a ground rod, metal water pipe, or concrete-encased electrode that is in direct contact with the earth and establishes a connection to ground.

The set of grounding electrodes bonded together to form a single grounding connection. Where multiple electrodes are present, the code generally requires them to be bonded into one system.

The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.

A reliable conductor that ensures the required electrical conductivity between metal parts required to be electrically connected. It may connect electrodes, equipment, or enclosures within the grounding system.

An unintentional connection between an ungrounded conductor and normally non-current-carrying metal parts, raceways, or earth. It is cleared by the equipment grounding path and overcurrent device.

A device that de-energizes a circuit within a set time when current to ground exceeds a threshold below that needed to protect conductors. It protects people from shock in wet or damp locations.

A device that detects and interrupts dangerous electrical arcs, such as from damaged or loose conductors, before they ignite surrounding material. It is commonly required on branch circuits serving dwelling unit living areas.

A system that disconnects a circuit when fault current to ground reaches a level that could damage equipment, typically set higher than GFCI thresholds. It is often used on large services and feeders.

The grounded conductor of a system that carries unbalanced current from line-to-neutral loads. It is bonded to ground only at the service or separately derived system, not downstream.

The clear, unobstructed area in front of electrical equipment required for safe examination, adjustment, servicing, and maintenance. Depth depends on voltage and whether live parts are exposed on the opposite side.

Space reserved solely for electrical equipment, extending from the floor to a height above the equipment and from the front to a distance behind it. Pipes, ducts, and leaks are generally prohibited there.

A single panel containing buses and automatic overcurrent devices, with or without switches, designed to be placed in a cabinet or cutout box. It distributes power to branch circuits or feeders.

The main switch or breaker that disconnects all service-entrance conductors from the building wiring. It must be clearly marked, readily accessible, and rated for the calculated service load.

A building or space type with unusual hazards or conditions, such as health care facilities, places of assembly, hazardous locations, or marinas, that triggers additional or modified code requirements.

An area where fire or explosion hazards may exist because of flammable gases, vapors, dusts, fibers, or flyings. Equipment and wiring methods must be specifically approved for the class, division or zone, and group.

Enclosures designed to contain an internal explosion and prevent ignition of surrounding flammable atmospheres, while operating at temperatures below ignition thresholds. It is used in certain classified locations.

A location designated by class, division or zone, and group based on the type and likelihood of flammable materials present. The classification dictates permissible wiring methods and equipment.

A building or portion used for medical, dental, or psychiatric care where patients are examined or treated. It imposes requirements for redundant grounding, isolated power, and patient care area receptacles.

Wiring installed for a limited time, such as at construction sites, carnivals, or holiday displays. It must be removed when the purpose ends and is subject to specific rules for support, protection, and GFCI use.