A device intended to provide limited overcurrent protection for specific applications and utilization equipment such as luminaires and appliances. This limited protection is in addition to the protection provided in the required branch circuit by the branch circuit overcurrent protective device.
An area with a sink and permanent facilities for food preparation and cooking.
Volatile Flammable Liquid
A flammable liquid having a flash point below 38°C (100°F), or a flammable liquid whose temperature is above its flash point, or a Class II combustible liquid that has a vapor pressure not exceeding 276 kPa (40 psia) at 38°C (100°F) and whose temperature is above its flash point.
Constructed or protected so that exposure to the weather will not interfere with successful operation.
An enclosure designed for surface mounting that has swinging doors or covers secured directly to and telescoping with the walls of the box proper.
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.
Accessible (as applied to equipment)
Admitting close approach; not guarded by locked doors, elevation, or other effective means.
Utilization equipment, generally other than industrial, that is normally built in standardized sizes or types and is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, and so forth.
Intersystem Bonding Termination
A device that provides a means for connecting communications system(s) grounding conductor(s) and bonding conductor(s) at the service equipment or at the disconnecting means for buildings or structures supplied by a feeder or branch circuit.
A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment.
Electrical Equipment for Use in Hazardous (Classified) Locations.
A building that consists solely of one dwelling unit.
The written consent of the authority having jurisdiction.
An area including a basin with one or more of the following: a toilet, a tub, or a shower.
Action requiring personal intervention for its control. As applied to an electric controller, nonautomatic control does not necessarily imply a manual controller, but only that personal intervention is necessary.
Switch, General-Use Snap
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.
Surge-Protective Device (SPD)
A protective device for limiting transient voltages by diverting or limiting surge current; it also prevents continued flow of follow current while remaining capable of repeating these functions and is designated as follows: Type 1: Permanently connected SPDs intended for installation between the secondary of the service transformer and the line side of the service disconnect overcurrent device. Type 2: Permanently connected SPDs intended for installation on the load side of the service disconnect overcurrent device, including SPDs located at the branch panel. Type 3: Point of utilization SPDs. Type 4: Component SPDs, including discrete components, as well as assemblies.
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.
Exposed (as applied to live parts)
Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts that are not suitably guarded, isolated, or insulated.
A conductor having no covering or electrical insulation whatsoever.
An automatic or nonautomatic device for transferring one or more load conductor connections from one power source to another.
Thermally Protected (as applied to motors)
The words Thermally Protected appearing on the nameplate of a motor or motor-compressor indicate that the motor is provided with a thermal protector.
Any shaftway, hatchway, well hole, or other vertical opening or space in which an elevator or dumbwaiter is designed to operate.
A unit of an electrical system that carries or controls electric 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 conducting object through which a direct connection to earth is established.
Copper-Clad Aluminum Conductors
Conductors drawn from a copper-clad aluminum rod with the copper metallurgically bonded to an aluminum core. The copper forms a minimum of 10 percent of the cross-sectional area of a solid conductor or each strand of a stranded conductor.
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.
Motor Control Center
An assembly of one or more enclosed sections having a common power bus and principally containing motor control units.
Connected (connecting) to ground or to a conductive body that extends the ground connection.
Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is 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.
A non-habitable room or space intended primarily for storage of garments and apparel.
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.
The current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
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.
An arrangement of incandescent lamps, electric-discharge lighting, or other electrically powered light sources to outline or call attention to certain features such as the shape of a building or the decoration of a window.
Authority Having Jurisdiction (AHJ)
An organization, office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.
A building that consists solely of two dwelling units.
A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
Any window used or designed to be used for the display of goods or advertising material, whether it is fully or partly enclosed or entirely open at the rear and whether or not it has a platform raised higher than the street floor level.
Voltage to Ground
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.
A system or circuit conductor that is intentionally grounded.
A load where the maximum current is expected to continue for 3 hours or more.
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.
Operation for alternate intervals of (1) load and no load; or (2) load and rest; or (3) load, no load, and rest.
That which is built or constructed.
In Sight From (Within Sight From, Within Sight)
Where this Code specifies that one equipment shall be “in sight from,” “within sight from,” or “within sight of,” and so forth, another equipment, the specified equipment is to be visible and not more than 15 m (50 ft) distant from the other.
A load where the wave shape of the steady-state current does not follow the wave shape of the applied voltage.
Equipment that utilizes electric energy for electronic, electromechanical, chemical, heating, lighting, or similar purposes.
An enclosure that is designed for either surface mounting or flush mounting and is provided with a frame, mat, or trim in which a swinging door or doors are or can be hung.
Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
Branch Circuit, Multiwire
A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.
The necessary equipment, usually consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the load end of service conductors to a building or other structure, or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.
A large single panel, frame, or assembly of panels on which are mounted on the face, back, or both, switches, overcurrent and other protective devices, buses, and usually instruments. Switchboards are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets.
A building or portion of a building in which one or more self-propelled vehicles can be kept for use, sale, storage, rental, repair, exhibition, or demonstration purposes.
Cooking Unit, Counter-Mounted
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 mountable controls.
An enclosure for use in underground systems, provided with an open or closed bottom, and sized to allow personnel to reach into, but not enter, for the purpose of installing, operating, or maintaining equipment or wiring or both.
Voltage (of a circuit)
The greatest root-mean-square (rms) (effective) difference of potential between any two conductors of the circuit concerned.
A protective device for limiting surge voltages by discharging or bypassing surge current; it also prevents continued flow of follow current while remaining capable of repeating these functions.
Ground-Fault Circuit Interrupter (GFCI)
A device intended for the protection of personnel that functions to deenergize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.
Branch Circuit, General-Purpose
A branch circuit that supplies two or more receptacles or outlets for lighting and appliances.
A switch intended for use in general distribution and branch circuits. It is rated in amperes, and it is capable of interrupting its rated current at its rated voltage.
A type of surface, flush, or freestanding raceway designed to hold conductors and receptacles, assembled in the field or at the factory.
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 that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.
Short-Circuit Current Rating
The prospective symmetrical fault current at a nominal voltage to which an apparatus or system is able to be connected without sustaining damage exceeding defined acceptance criteria.
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.
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 fixed, stationary, or portable selfcontained, electrically illuminated utilization equipment with words or symbols designed to convey information or attract attention.
Identified (as applied to equipment)
Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement.
Acceptable to the authority having jurisdiction.
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. It may also include parts to protect the light source or the ballast or to distribute the light. A lampholder itself is not a luminaire.
An outlet intended for the direct connection of a lampholder or luminaire.
Surrounded by a case, housing, fence, or wall(s) that prevents persons from accidentally contacting energized parts.
A conductor encased within material of composition and thickness that is recognized by this Code as electrical insulation.
Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and that operates at such an external temperature that a surrounding flammable atmosphere will not be ignited thereby.
Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes, or vapors.
Thermal Protector (as applied to motors)
A protective device for assembly as an integral part of a motor or motorcompressor that, when properly applied, protects the motor against dangerous overheating due to overload and failure to start.
Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current, pressure, temperature, or mechanical configuration.
A reliable conductor to ensure the required electrical conductivity between metal parts required to be electrically connected.
Constructed so that dust will not enter the enclosing case under specified test conditions.
Bonding Jumper, Main
The connection between the grounded circuit conductor and the equipment grounding conductor at the service.
Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. Examples of such locations include partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some cold storage warehouses.
Branch Circuit, Individual
A branch circuit that supplies only one utilization equipment.
All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.
Bonding Jumper, Equipment
The connection between two or more portions of the equipment grounding conductor.
The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
Without live parts exposed to a person on the operating side of the equipment.
Connected to establish electrical continuity and conductivity.
Switch, Bypass Isolation
A manually operated device used in conjunction with a transfer switch to provide a means of directly connecting load conductors to a power source and of disconnecting the transfer switch.
Rendered inaccessible by the structure or finish of the building. Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them.
A building that contains three or more dwelling units.
Branch Circuit, Appliance
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 switch intended for isolating an electrical circuit from the source of power. It has no interrupting rating, and it is intended to be operated only after the circuit has been opened by some other means.
A single unit, providing complete and independent living facilities for one or more persons, including permanent provisions for living, sleeping, cooking, and sanitation.
Exposed (as applied to wiring methods)
On or attached to the surface or behind panels designed to allow access.
Grounding Electrode Conductor
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.
Any electrical circuit that energizes signaling equipment.
Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit, or ground fault.
A point on the wiring system at which current is taken to supply utilization equipment.
The point of connection between the facilities of the serving utility and the premises wiring.
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.
Grounding Conductor, Equipment (EGC)
The conductive path installed to connect normally non–currentcarrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode, or both.
Accessible (as applied to wiring methods)
Capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building.
A structure that stands alone or that is cut off from adjoining structures by fire walls with all openings therein protected by approved fire doors.
Isolated (as applied to location)
Not readily accessible to persons unless special means for access are used.
Attachment Plug (Plug Cap) (Plug)
A device that, by insertion in a receptacle, establishes a connection between the conductors of the attached flexible cord and the conductors connected permanently to the receptacle.
Constructed so that moisture will not enter the enclosure under specified test conditions.
Operation at a substantially constant load for an indefinitely long time.
Energized conductive components.
The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.
Solar Photovoltaic System
The total components and subsystems that, in combination, convert solar energy into electric energy suitable for connection to a utilization load.
Accessible, Readily (Readily Accessible)
Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, and so forth.
The underground service conductors between the street main, including any risers at a pole or other structure or from transformers, and the first point of connection to the service-entrance conductors in a terminal box or meter or other enclosure, inside or outside the building wall. Where there is no terminal box, meter, or other enclosure, the point of connection is considered to be the point of entrance of the service conductors into the building.
The highest current at rated voltage that a device is intended to interrupt under standard test 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.