Chapter 35 Electrical Definitions

Capable of being reached quickly for operation, renewal or inspections, without requiring those to whom ready access is requisite to take actions such as to use tools, other than keys, to climb over or under, to remove obstacles or to resort to portable ladders, etc.

The maximum current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

Utilization equipment that is fastened in place, stationary or portable; is normally built in a standardized size or type; and is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.

Acceptable to the authority having jurisdiction.

A device intended to provide protection from the effects of arc-faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc-fault is detected.

A device that, by insertion into a weight-supporting ceiling receptacle, establishes a connection between the conductors of the attached utilization equipment and the branch-circuit conductors connected to the weight-supporting ceiling receptacle.

A device that, by insertion into a receptacle, establishes connection between the conductors of the attached flexible cord and the conductors connected permanently to the receptacle.

Performing a function without the necessity of human intervention.

An area, including a sink, with one or more of the following: a toilet, a urinal, a tub, a shower, a bidet, or similar plumbing fixture.

Connected to establish electrical continuity and conductivity.

A conductor that ensures the required electrical conductivity between metal parts that are required to be electrically connected.

The connection between two or more portions of the equipment grounding conductor.

The connection between the grounded circuit conductor and the equipment grounding conductor, or the supply-side bonding jumper, or both, at the service.

A conductor installed on the supply side of a service or within a service equipment enclosure(s) that ensures the required electrical conductivity between metal parts required to be electrically connected.

A branch circuit that supplies energy to one or more outlets to which appliances are to be connected, and that has no permanently connected luminaires that are not a part of an appliance.

A branch circuit that supplies two or more receptacle outlets or outlets for lighting and appliances.

A branch circuit that supplies only one utilization equipment.

A branch circuit consisting of two or more ungrounded conductors having voltage difference between them, and a grounded conductor having equal voltage difference between it and each ungrounded conductor of the circuit, and that is connected to the neutral or grounded conductor of the system.

The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

An enclosure designed either for surface or flush mounting and provided with a frame, mat or trim in which a swinging door or doors are or may be hung.

A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.

The portion of the wiring system between the load side of a Class 2 power source and the connected equipment. Due to its power limitations, a Class 2 circuit considers safety from a fire shock initiation standpoint and provides acceptable protection from electric shock.

A nonhabitable room or space intended primarily for storage of garments and apparel.

The area within a clothes closet in which combustible material can be kept.

Rendered inaccessible by the structure or finish of the building.

A conductor having no covering or electrical insulation whatsoever.

Conductor drawn from a copper-clad aluminum rod, with the copper metallurgically bonded to an aluminum core.

A conductor encased within material of composition or thickness that is not recognized by this code as electrical insulation.

A conductor encased within material of composition and thickness that is recognized by this code as electrical insulation.

A separate portion of a conduit or tubing system that provides access through a removable cover(s) to the interior of the system at a junction of two or more sections of the system or at a terminal point of the system. Boxes such as FS and FD or larger cast or sheet metal boxes are not classified as conduit bodies.

A device that establishes a connection between two or more conductors or between one or more conductors and a terminal by means of mechanical pressure and without the use of solder.

A load where the maximum current is expected to continue for 3 hours or more.

A cooking appliance designed for mounting in or on a counter and consisting of one or more heating elements, internal wiring and built-in or separately mountable controls.

Areas or enclosures without adequate ventilation, where electrical equipment is located and pool sanitation chemicals are stored, handled or dispensed.

An enclosure designed for surface mounting and having swinging doors or covers secured directly to and telescoping with the walls of the box proper (see “Cabinet”).

Without live parts exposed to a person on the operating side of the equipment.

The ratio of the maximum demand of a system, or part of a system, to the total connected load of a system or the part of the system under consideration.

A unit of an electrical system that carries or controls electrical energy as its principal function.

A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.

A single unit, providing complete and independent living facilities for one or more persons, including permanent provisions for living, sleeping, cooking and sanitation.

Surrounded by a case, housing, fence or walls that will prevent persons from accidentally contacting energized parts.

The case or housing of apparatus, or the fence or walls surrounding an installation, to prevent personnel from accidentally contacting energized parts or to protect the equipment from physical damage.

Electrically connected to, or is, a source of voltage.

Conductive material that could become energized because of the failure of electrical insulation or electrical spacing.

A general term including material, fittings, devices, appliances, luminaires, apparatus, machinery and the like used as a part of, or in connection with, an electrical installation.

Capable of being operated without exposing the operator to contact with live parts.

All circuit conductors between the service equipment, or the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

An accessory such as a locknut, bushing or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function.

A structure designed to support a wet-niche luminaire assembly and intended for mounting in a pool or fountain structure.

The earth.

Connected (connecting) to ground or to a conductive body that extends the ground connection.

Intentionally connected to earth through a ground connection or connections of sufficiently low impedance and having sufficient current-carrying capacity to prevent the buildup of voltages that may result in undue hazards to connected equipment or to persons.

A system or circuit conductor that is intentionally grounded.

A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a ground-fault current exceeds the value for a Class A device.

An electrically conductive path from the point of a ground fault on a wiring system through normally noncurrent-carrying conductors, grounded conductors, equipment, or the earth to the electrical supply source.

An intentionally constructed, low-impedance electrically conductive path designed and intended to carry current under ground-fault conditions from the point of a ground fault on a wiring system to the electrical supply source and that facilitates the operation of the overcurrent protective device or ground-fault detectors.

A conductive path that is part of an effective ground-fault current path and connects normally noncurrent-carrying metal parts of equipment together and to the system grounded conductor, the grounding electrode conductor or both.

A conducting object through which a direct connection to earth is established.

A conductor used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system.

Covered, shielded, fenced, enclosed or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.

A room in a building for living, sleeping, eating or cooking, but excluding bathrooms, toilet rooms, closets, hallways, storage or utility spaces, and similar areas.

A permanently installed bathtub equipped with a recirculating piping system, pump and associated equipment. It is designed so it can accept, circulate and discharge water upon each use.

(As applied to equipment.) Recognizable as suitable for the specific purpose, function, use, environment, application, etc., where described in a particular code requirement.

Where this code specifies that one piece of equipment shall be “in sight from,” “within sight from,” “within sight of,” or similarly stated from/of another piece of equipment, the specified equipment must be visible and not more than 50 feet (15.2 m) distant from the other.

The highest current at rated voltage that a device is identified to interrupt under standard test conditions.

A device that provides a means for connecting intersystem bonding conductors for communications systems to the grounding electrode system.

(As applied to location.) Not readily accessible to persons unless special means for access are used.

An area with a sink and permanent provisions for food preparation and cooking.

Equipment or materials to which has been attached a label, symbol or other identifying mark of an organization acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

An area containing or designed to contain a laundry tray, clothes washer or clothes dryer.

A lighting assembly consisting of a luminaire intended for installation in the wall of a spa, hot tub, or storable pool, and a cord-and-plug-connected transformer or power supply.

A lighting assembly intended for installation above grade, on or through the wall of a pool, consisting of two interconnected groups of components separated by the pool wall.

An outlet intended for the direct connection of a lampholder or luminaire.

A manufactured assembly designed to support and energize luminaires that are capable of being readily repositioned on the track. Its length can be altered by the addition or subtraction of sections of track.

Equipment, materials or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states either that the equipment, material or services meets identified standards or has been tested and found suitable for a specified purpose.

Energized conductive components.

Location protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture.

A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Installations underground or in concrete slabs or masonry in direct contact with the earth and locations subject to saturation with water or other liquids, such as vehicle-washing areas, and locations exposed to weather.

A voltage not exceeding the following values:

1. 1.

   15 volts (RMS) for sinusoidal AC.

2. 2.

   21.2 volts peak for nonsinusoidal AC.

3. 3.

   30 volts for continuous DC.

4. 4.

   12.4 volts peak for DC that is interrupted at a rate of 10 to 200 Hz.

A complete lighting unit consisting of a light source such as a lamp or lamps together with the parts designed to position the light source and connect it to the power supply. A luminaire can include parts to protect the light source or the ballast or to distribute the light. A lamp-holder itself is not a luminaire.

A luminaire intended for installation in the floor or wall of a pool, spa, or fountain in a niche that is sealed against the entry of water.

A luminaire intended for installation above or below the water without a niche.

A luminaire intended for installation in a forming shell mounted in a pool or fountain structure where the luminaire will be completely surrounded by water.

The highest level that water can reach before it spills out.

A surface, flush or freestanding assemblage with a raceway and fittings or other enclosure provided with one or more receptacles, for the purpose of supplying power to utilization equipment.

The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.

The common point on a wye connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system.

A point on the wiring system at which current is taken to supply utilization equipment.

A housing shield intended to fit over a faceplate for flush-mounted wiring devices, or an integral component of an outlet box or of a faceplate for flush-mounted wiring devices. The hood does not serve to complete the electrical enclosure; it reduces the risk of water coming in contact with electrical components within the hood, such as attachment plugs, current taps, surge protective devices, direct plug-in transformer units, or wiring devices.

Any current in excess of the rated current of equipment or the ampacity of a conductor. Such current might result from overload, short circuit or ground fault.

Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.

A single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat or power circuits, designed to be placed in a cabinet or cutout box placed in or against a wall, partition or other support and accessible only from the front.

An assembly of buses and connections, overcurrent devices, and control apparatus with or without switches or other equipment, installed in a cabinet, cutout box, or enclosure suitable for a panelboard application.

A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.

Manufactured or field-constructed equipment designed to contain water on a permanent or semipermanent basis and used by persons for swimming, wading, immersion, or therapeutic purposes, but not including bodies of water incorporated as part of an industrial process or lakes, lagoons, surf parks, or other natural and man-made bodies of water that may incorporate swimming and swimming areas.

Those that are constructed or installed in the ground or partially in the ground, and all pools installed inside of a building, whether or not served by electrical circuits of any nature.

Pools installed entirely on or above the ground that are intended to be stored when not in use and are designed for ease of relocation, regardless of water depth.

Motor-driven equipment designed to cover and uncover the water surface of a pool by means of a flexible sheet or rigid frame.

An enclosed assembly that may include receptacles, circuit breakers, fuseholders, fused switches, buses and watthour meter mounting means, intended to supply and control power to mobile homes, recreational vehicles or boats, or to serve as a means for distributing power required to operate mobile or temporarily installed equipment.

Interior and exterior wiring, including power, lighting, control and signal circuit wiring together with all of their associated hardware, fittings and wiring devices, both permanently and temporarily installed. This includes one of the following:

1. 1.

   Wiring from the service point or power source to the outlets

2. 2.

   Wiring from and including the power source to the outlets where there is no service point

Such wiring does not include wiring internal to appliances, luminaires, motors, controllers, and similar equipment.

One who has the skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.

An enclosed channel expressly for holding wires, cables, or busbars, with additional functions as permitted in this code.

Constructed, protected or treated so as to prevent rain from interfering with the successful operation of the apparatus under specified test conditions.

Constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions.

A contact device installed at the outlet for the connection of an attachment plug, or for the direct connection of electrical utilization equipment designed to mate with the corresponding contact device. A single receptacle is a single contact device with no other contact device on the same yoke or strap. A multiple receptacle is two or more contact devices on the same yoke or strap.

A contact device installed at an outlet box for the connection and support of luminaries or ceiling-suspended (paddle) fans using a weight-supporting attachment fitting (WSAF).

An outlet where one or more receptacles are installed.

Electromechanical systems, equipment, apparatus or components that are restored to operating conditions. This process differs from the normal servicing of equipment that remains within a facility, or replacement of listed equipment on a one-toone basis.

Any electrical circuit that controls any other circuit through a relay or an equivalent device.

The conductors and equipment connecting the serving utility to the wiring system of the premises served.

Service conductors made up in the form of a cable.

The conductors from the service point to the service disconnecting means.

The overhead conductors between the service point and the first point of connection to the service-entrance conductors at the building or other structure.

The underground conductors between the service point and the first point of connection to the service-entrance conductors in a terminal box, meter, or other enclosure, inside or outside of the building wall.

The overhead conductors between the serving utility and the service point.

The necessary equipment, consisting of a circuit breaker(s) or switch(es) and fuse(s), and their accessories, connected to the serving utility and intended to constitute the main control and disconnect of the serving utility.

The underground service conductors between the electric utility supply system and the service point.

The point of connection between the facilities of the serving utility and the premises wiring.

The service conductors between the terminals of the service equipment to the service drop, overhead service conductors, service lateral, or underground service conductors.

Any electrical circuit that energizes signaling equipment.

A hydromassage pool, or tub for recreational or therapeutic use, not located in health care facilities, designed for immersion of users, and usually having a filter, heater and motor-driven blower. It may be installed indoors or outdoors, on the ground or supporting structure, or in the ground or supporting system. Generally, they are not designed or intended to have their contents drained or discharged after each use.

A factory-fabricated unit consisting of water-circulating, heating and control equipment mounted on a common base, intended to operate a spa or hot tub. Equipment can include pumps, air blowers, heaters, lights, controls, sanitizer generators, and so forth.

A factory-fabricated unit consisting of a spa or hot tub vessel with all water-circulating, heating and control equipment integral to the unit. Equipment can include pumps, air blowers, heaters, lights, controls, sanitizer generators, and so forth.

That which is built or constructed, other than equipment.

A switch intended for use in general distribution and branch circuits. It is rated in amperes and is capable of interrupting its rated current at its rated voltage.

A form of general-use switch constructed so that it can be installed in device boxes or on box covers or otherwise used in conjunction with wiring systems recognized by this code.

A switch intended for isolating an electric circuit from the source of power. It has no interrupting rating and is intended to be operated only after the circuit has been opened by some other means.

A switch, rated in horsepower that is capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage.

Not connected to ground or to a conductive body that extends the ground connection.

Equipment that utilizes electric energy for electronic, electromechanical, chemical, heating, lighting or similar purposes.

Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes or vapors.

The greatest root-mean-square (rms) (effective) difference of potential between any two conductors of the circuit concerned.

A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240).

For grounded circuits, the voltage between the given conductor and that point or conductor of the circuit that is grounded. For ungrounded circuits, the greatest voltage between the given conductor and any other conductor of the circuit.

Constructed so that moisture will not enter the enclosure under specified test conditions.

Constructed or protected so that exposure to the weather will not interfere with successful operation.