Article 100 - Definitions

Question 1

Identified (as applied to equipment).

Answer 1

Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement. (CMP-1)

Question 2

In Sight From (Within Sight From, Within Sight).

Answer 2

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. (CMP-1)

Question 3

Industrial Control Panel.

Answer 3

An assembly of two or more components consisting of one of the following: (1) power circuit components only, such as motor controllers, overload relays, fused disconnect switches, and circuit breakers; (2) control circuit components only, such as push buttons, pilot lights, selector switches, timers, switches, and control relays; (3) a combination of power and control circuit components. These components, with associated wiring and terminals, are mounted on, or contained within, an enclosure or mounted on a subpanel.

Question 4

Information Technology Equipment (ITE).

Answer 4

Equipment and systems rated 1000 volts or less, normally found in offices or other business establishments and similar environments classified as ordinary locations, that are used for creation and manipulation of data, voice, video, and similar signals that are not communications equipment as defined in Part I of Article 100 and do not process communications circuits as defined

Question 5

Innerduct.

Answer 5

A nonmetallic raceway placed within a larger raceway. (CMP-16)

Question 6

Interactive Inverter.

Answer 6

An inverter intended for use in parallel with an electric utility to supply common loads that may deliver power to the utility. (CMP-13)

Question 7

Interactive System.

Answer 7

An electric power production system that is operating in parallel with and capable of delivering energy to an electric primary source supply system. (CMP-4)

Question 8

Interrupting Rating.

Answer 8

The highest current at rated voltage that a device is identified to interrupt under standard test conditions. (CMP-10)

Question 9

Intersystem Bonding Termination.

Answer 9

A device that provides a means for connecting intersystem bonding conductors for communications systems to the grounding electrode system.(CMP-16)

Question 10

Intrinsically Safe Apparatus.

Answer 10

Apparatus in which all the circuits are intrinsically safe. (CMP-14)

Question 11

Intrinsically Safe System [as applied to Hazardous (Classified) Locations].

Answer 11

An assembly of interconnected intrinsically safe apparatus, associated apparatus, and interconnecting cables, in that those parts of the system that may be used in hazardous (classified) locations are intrinsically safe circuits. (CMP-14)

Question 12

Isolated (as applied to location).

Answer 12

Not readily accessible to persons unless special means for access are used. (CMP-1)

Question 13

Kitchen.

Answer 13

An area with a sink and permanent provisions for food preparation and cooking. (CMP-2)

Question 14

Labeled.

Answer 14

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. (CMP-1)

Question 15

Lighting Outlet.

Answer 15

An outlet intended for the direct connection of a lampholder or luminaire. (CMP-18)

Question 16

Lighting Track (Track Lighting).

Answer 16

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.(CMP-18)

Question 17

Listed.

Answer 17

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. (CMP-1)

Question 18

Live Parts.

Answer 18

Energized conductive components. (CMP-1)

Question 19

Location, Damp.

Answer 19

Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. (CMP-1)

Question 20

Location, Dry.

Answer 20

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. (CMP-1)

Question 21

Location, Wet.

Answer 21

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. (CMP-1)

Question 22

Luminaire.

Answer 22

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. (CMP-18)

Question 23

Mobile Equipment.

Answer 23

Equipment with electrical components suitable to be moved only with mechanical aids or is provided with wheels for movement by person(s) or powered devices. (CMP-14)

Question 24

Motor Control Center.

Answer 24

An assembly of one or more enclosed sections having a common power bus and principally containing motor control units. (CMP-11)

Question 25

Multioutlet Assembly.

Answer 25

A type of surface, flush, or freestanding raceway designed to hold conductors and receptacles, assembled in the field or at the factory. (CMP-18)

Question 26

Neutral Conductor.

Answer 26

The conductor connected to the neutral point of a system that is intended to carry current under normal conditions. (CMP-5)

Question 27

Neutral Point.

Answer 27

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. (CMP-5)

Question 28

Nonautomatic.

Answer 28

Requiring human intervention to perform a function. (CMP-1)

Question 29

Nonconductive Optical Fiber Cable.

Answer 29

A factory assembly of one or more optical fibers having an overall covering and containing no electrically conductive materials. (CMP-16)

Question 30

Nonincendive Circuit [as applied to Hazardous (Classified) Locations].

Answer 30

A circuit, other than field wiring, in which any arc or thermal effect produced under intended operating conditions of the equipment, is not capable, under specified test conditions, of igniting the flammable gas–air, vapor–air, or dust–air mixture. (CMP-14)

Question 31

Nonincendive Component [as applied to Hazardous (Classified) Locations].

Answer 31

A component having contacts for making or breaking an incendive circuit and the contacting mechanism is constructed so that the component is incapable of igniting the specified flammable gas–air or vapor–air mixture. The housing of a nonincendive component is not intended to exclude the flammable atmosphere or contain an explosion. (CMP-14)

Question 32

Nonincendive Equipment [as applied to Hazardous (Classified) Locations].

Answer 32

Equipment having electrical/electronic circuitry that is incapable, under normal operating conditions, of causing ignition of a specified flammable gas–air, vapor–air, or dust–air mixture due to arcing or thermal means. (CMP-14)

Question 33

Nonincendive Field Wiring [as applied to Hazardous (Classified) Locations].

Answer 33

Wiring that enters or leaves an equipment enclosure and, under normal operating conditions of the equipment, is not capable, due to arcing or thermal effects, of igniting the flammable gas–air, vapor–air, or dust–air mixture. Normal operation includes opening, shorting, or grounding the field wiring. (CMP-14)

Question 34

Nonincendive Field Wiring Apparatus [as applied to Hazardous (Classified) Locations].

Answer 34

Apparatus intended to be connected to nonincendive field wiring. (CMP-14)

Question 35

Nonlinear Load.

Answer 35

A load where the wave shape of the steady-state current does not follow the wave shape of the applied voltage. (CMP-1)

Question 36

Oil Immersion [as applied to Hazardous (Classified) Locations].

Answer 36

Electrical equipment immersed in a protective liquid in such a way that an explosive atmosphere that may be above the liquid or outside the enclosure cannot be ignited. (CMP-14)

Question 37

Optical Fiber Cable.

Answer 37

A factory assembly or field assembly of one or more optical fibers having an overall covering. (CMP-16)

Question 38

Outlet.

Answer 38

A point on the wiring system at which current is taken to supply utilization equipment. (CMP-1)

Question 39

Outline Lighting.

Answer 39

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. (CMP-18)

Question 40

Overcurrent.

Answer 40

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. (CMP-10)

Question 41

Overcurrent Protective Device, Branch-Circuit.

Answer 41

A device capable of providing protection for service, feeder, and branch circuits and equipment over the full range of overcurrents between its rated current and its interrupting rating. Such devices are provided with interrupting ratings appropriate for the intended use but no less than 5000 amperes. (CMP-10)

Question 42

Overcurrent Protective Device, Supplementary.

Answer 42

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. (CMP-10)

Question 43

Overload.

Answer 43

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. (CMP-10)

Question 44

Panelboard.

Answer 44

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. (CMP-9)

Question 45

Photovoltaic (PV) System.

Answer 45

The total components and subsystem that, in combination, convert solar energy into electric energy for connection to a utilization load. (CMP-4)

Question 46

Plenum.

Answer 46

A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system. (CMP-3)

Question 47

Portable Equipment.

Answer 47

Equipment with electrical components suitable to be moved by a single person without mechanical aids. (CMP-14)

Question 48

Power Outlet.

Answer 48

An enclosed assembly that may include receptacles, circuit breakers, fuseholders, fused switches, buses, and watt-hour meter mounting means; intended to supply and control power to mobile homes, recreational vehicles, park trailers, or boats or to serve as a means for distributing power required to operate mobile or temporarily installed equipment.(CMP-19)

Question 49

Premises Wiring (System).

Answer 49

Interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all their associated hardware, fittings, and wiring devices, both permanently and temporarily installed. This includes (a) wiring from the service point or power source to the outlets or (b) 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, motor control centers, and similar equipment. (CMP-1)

Question 50

Pressurized [as applied to Hazardous (Classified) Locations].

Answer 50

The process of supplying an enclosure with a protective gas with or without continuous flow, at sufficient pressure to prevent the entrance of combustible dust or ignitible fibers/flyings. (CMP-14)

Question 51

Process Seal [as applied to Hazardous (Classified) Locations].

Answer 51

A seal between electrical systems and flammable or combustible process fluids where a failure could allow the migration of process fluids into the premises’ wiring system. (CMP-14)

Question 52

Purged and Pressurized [as applied to Hazardous (Classified) Locations].

Answer 52

The process of (1) purging, supplying an enclosure with a protective gas at a sufficient flow and positive pressure to reduce the concentration of any flammable gas or vapor initially present to an acceptable level; and (2) pressurization, supplying an enclosure with a protective gas with or without continuous flow at sufficient pressure to prevent the entrance of a flammable gas or vapor, a combustible dust, or an ignitible fiber. (CMP-14)

Question 53

Qualified Person.

Answer 53

One who has 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. (CMP-1)

Question 54

Raceway.

Answer 54

An enclosed channel designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code. (CMP-8)

Question 55

Rainproof

Answer 55

Constructed, protected, or treated so as to prevent rain from interfering with the successful operation of the apparatus under specified test conditions. (CMP-1)

Question 56

Raintight.

Answer 56

Constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions. (CMP-1)

Question 57

Receptacle.

Answer 57

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. A multiple receptacle is two or more contact devices on the same yoke. (CMP-18)

Question 58

Receptacle Outlet.

Answer 58

An outlet where one or more receptacles are installed. (CMP-18)

Question 59

Remote-Control Circuit.

Answer 59

Any electrical circuit that controls any other circuit through a relay or an equivalent device. (CMP-3)

Question 60

Retrofit Kit.

Answer 60

A general term for a complete subassembly of parts and devices for field conversion of utilization equipment. (CMP-18)

Question 61

Sealable Equipment.

Answer 61

Equipment enclosed in a case or cabinet that is provided with a means of sealing or locking so that live parts cannot be made accessible without opening the enclosure. (CMP-1)

Question 62

Separately Derived System.

Answer 62

An electrical source, other than a service, having no direct connection(s) to circuit conductors of any other electrical source other than those established by grounding and bonding connections. (CMP-5)

Question 63

Service.

Answer 63

The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served. (CMP-4)

Question 64

Service Cable.

Answer 64

Service conductors made up in the form of a cable. (CMP-4)

Question 65

Service Conductors.

Answer 65

The conductors from the service point to the service disconnecting means. (CMP-4)

Question 66

Service Conductors, Overhead.

Answer 66

The overhead conductors between the service point and the first point of connection to the service-entrance conductors at the building or other structure. (CMP-4)

Question 67

Service Conductors, Underground.

Answer 67

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 the building wall. (CMP-4)

Question 68

Service Drop.

Answer 68

The overhead conductors between the utility electric supply system and the service point. (CMP-4)

Question 69

Service-Entrance Conductors, Overhead System.

Answer 69

The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls, where joined by tap or splice to the service drop or overhead service conductors. (CMP-4)

Question 70

Service-Entrance Conductors, Underground System.

Answer 70

The service conductors between the terminals of the service equipment and the point of connection to the service lateral or underground service conductors. (CMP-4)

Question 71

Service Equipment.

Answer 71

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. (CMP-4)

Question 72

Service Lateral.

Answer 72

The underground conductors between the utility electric supply system and the service point. (CMP-4)

Question 73

Service Point.

Answer 73

The point of connection between the facilities of the serving utility and the premises wiring. (CMP-4)

Question 74

Short-Circuit Current Rating.

Answer 74

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. (CMP-10)

Question 75

Show Window.

Answer 75

Any window, including windows above doors, 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. (CMP-2)

Question 76

Signaling Circuit.

Answer 76

Any electrical circuit that energizes signaling equipment. (CMP-3)

Question 77

Simple Apparatus [as applied to Hazardous (Classified) Locations].

Answer 77

An electrical component or combination of components of simple construction with well-defined electrical parameters that does not generate more than 1.5 volts, 100 mA, and 25 mW, or a passive component that does not dissipate more than 1.3 watts and is compatible with the intrinsic safety of the circuit in which it is used. (CMP-14)

Question 78

Special Permission.

Answer 78

The written consent of the authority having jurisdiction. (CMP-1)

Question 79

Stand-Alone System.

Answer 79

A system that supplies power independently of an electrical production and distribution network.(CMP-4)

Question 80

Structure.

Answer 80

That which is built or constructed, other than equipment. (CMP-1)

Question 81

Surge Arrester.

Answer 81

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. (CMP-5)

Question 82

Surge-Protective Device (SPD).

Answer 82

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. (CMP-5)

Question 83

Switch, Bypass Isolation.

Answer 83

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. (CMP-13)

Question 84

Switch, General-Use.

Answer 84

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. (CMP-9)

Question 85

Switch, General-Use Snap.

Answer 85

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. (CMP-9)

Question 86

Switch, Isolating.

Answer 86

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. (CMP-9)

Question 87

Switch, Motor-Circuit.

Answer 87

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. (CMP-11)

Question 88

Switch, Transfer.

Answer 88

An automatic or nonautomatic device for transferring one or more load conductor connections from one power source to another. (CMP-13)

Question 89

Switchboard.

Answer 89

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. These assemblies are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets. (CMP-9)

Question 90

Switchgear.

Answer 90

An assembly completely enclosed on all sides and top with sheet metal (except for ventilating openings and inspection windows) and containing primary power circuit switching, interrupting devices, or both, with buses and connections. The assembly may include control and auxiliary devices. Access to the interior of the enclosure is provided by doors, removable covers, or both. (CMP-9)

Question 91

Thermal Protector (as applied to motors).

Answer 91

A protective device for assembly as an integral part of a motor or motor-compressor that, when properly applied, protects the motor against dangerous overheating due to overload and failure to start. (CMP-11)

Question 92

Thermally Protected (as applied to motors).

Answer 92

The words Thermally Protected appearing on the nameplate of a motor or motor-compressor indicate that the motor is provided with a thermal protector. (CMP-11)

Question 93

Unclassified Locations [as applied to Hazardous (Classified) Locations].

Answer 93

Locations determined to be neither Class I, Division 1; Class I, Division 2; Class I, Zone 0; Class I, Zone 1; Class I, Zone 2; Class II, Division 1; Class II, Division 2; Class III, Division 1; Class III, Division 2; Zone 20; Zone 21; Zone 22; nor any combination thereof. (CMP-14)

Question 94

Ungrounded

Answer 94

Not connected to ground or to a conductive body that extends the ground connection. (CMP-5)

Question 95

Uninterruptible Power Supply.

Answer 95

A power supply used to provide alternating current power to a load for some period of time in the event of a power failure. (CMP-13)

Question 96

Utilization Equipment.

Answer 96

Equipment that utilizes electric energy for electronic, electromechanical, chemical, heating, lighting, or similar purposes. (CMP-1)

Question 97

Ventilated.

Answer 97

Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes, or vapors.(CMP-14)

Question 98

Volatile Flammable Liquid.

Answer 98

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. (CMP-14)

Question 99

Voltage (of a circuit).

Answer 99

The greatest root-mean-square (rms) (effective) difference of potential between any two conductors of the circuit concerned. (CMP-1)

Question 100

Voltage, Nominal.

Answer 100

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). (CMP-1)

Question 101

Voltage to Ground.

Answer 101

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. (CMP-1)

Question 102

Watertight.

Answer 102

Constructed so that moisture will not enter the enclosure under specified test conditions. (CMP-1)

Question 103

Weatherproof.

Answer 103

Constructed or protected so that exposure to the weather will not interfere with successful operation. (CMP-1)