xah

e enclosures are required by 314.30 to be “identified” for use in underground systems. The installation of one type of handhole enclosure is shown below. [Courtesy of Quazite® (Hubbell Lenoir City, Inc.)] Hazard Current. For a given set of connections in an isolated powe...

e enclosures are required by 314.30 to be “identified” for use in underground systems. The installation of one type of handhole enclosure is shown below. [Courtesy of Quazite® (Hubbell Lenoir City, Inc.)] Hazard Current. For a given set of connections in an isolated power system, the total current that would flow through a low impedance if it were connected between either isolated conductor and ground. [99:3.3.72] (517) (CMP-15) Hazard Current, Fault. (Fault Hazard Current) The hazard current of a given isolated power system with all devices connected except the line isolation monitor. [99:3.3.72.1] (517) (CMP-15) Monitor Hazard Current. The hazard current of the line isolation monitor alone. [99:3.3.72.2] (517) (CMP-15) Total Hazard Current. The hazard current of a given isolated system with all devices, including the line isolation monitor, connected. [99:3.3.72.3] (517) (CMP-15) Header. Transverse metal raceways for electrical conductors, providing access to predetermined cells of a precast cellular concrete floor, thereby permitting the installation of electrical conductors from a distribution center to the floor cells. (CMP-8) Health Care Facilities. Buildings, portions of buildings, or mobile enclosures in which human medical, dental, psychiatric, nursing, obstetrical, or surgical care is provided. [99:3.3.73] (CMP-15) Informational Note: Examples of health care facilities include, but are not limited to, hospitals, nursing homes, limited care facilities, clinics, medical and dental offices, and ambulatory care centers, whether permanent or movable. ENHANCED CONTENT Collapse The term health care facility should not be confused with the term health care occupancy. All health care occupancies, including ambulatory health care occupancies, are considered health care facilities; however, not all health care facilities are considered health care occupancies. A medical office building can be a medical facility, but under NFPA 101, Life Safety Code, it typically would be a business occupancy. A hospital is a health care facility, but it can be several different occupancies (health care, assembly, business, ambulatory health care, and so forth). The NEC does not designate the type of facility or level of care provided. The governing body of the facility determines the type of services being provided at a facility. For example, depending on the jurisdiction, a chiropractic office might or might not be a facility covered under Article 517. Health Care Facility’s Governing Body. The person or persons who have the overall legal responsibility for the operation of a health care facility. [99:3.3.74] (517) (CMP-15) Heating Equipment. Any equipment that is used for heating purposes and whose heat is generated by induction or dielectric methods. (665) (CMP-12) Heating Panel. A complete assembly provided with a junction box or a length of flexible conduit for connection to a branch circuit. (CMP-17) Heating Panel Set. A rigid or nonrigid assembly provided with nonheating leads or a terminal junction assembly identified as being suitable for connection to a wiring system. (CMP-17) Heating System. A complete system consisting of components such as heating elements, fastening devices, nonheating circuit wiring, leads, temperature controllers, safety signs, junction boxes, raceways, and fittings. (426) (CMP-17) Heating System, Impedance. (Impedance Heating System) A system in which heat is generated in an object, such as a pipe, rod, or combination of such objects serving as a heating element, by causing current to flow through such objects by direct connection to an ac voltage source from an isolating transformer. In some installations the object is embedded in the surface to be heated or constitutes the exposed component to be heated. (CMP-17) Heating System, Induction. (Induction Heating System) A system in which heat is generated in a pipeline or vessel wall by inducing current in the pipeline or vessel wall from an external isolated ac field source. (CMP-17) Heating System, Skin Effect. (Skin-Effect Heating System) A system in which heat is generated on the inner surface of a ferromagnetic envelope embedded in or fastened to the surface to be heated. Informational Note: Typically, an electrically insulated conductor is routed through and connected to the envelope at the other end. The envelope and the electrically insulated conductor are connected to an ac voltage source from an isolating transformer. (CMP-17) Hermetic Refrigerant Motor-Compressor. A combination consisting of a compressor and motor, both of which are enclosed in the same housing, with no external shaft or shaft seals, with the motor operating in the refrigerant. (CMP-11) Hoistway. Any shaftway, hatchway, well hole, or other vertical opening or space in which an elevator or dumbwaiter is designed to operate. (CMP-12) Hospital. A building or portion thereof used on a 24-hour basis for the medical, psychiatric, obstetrical, or surgical care of four or more inpatients. [101:3.3.152] (CMP-15) Host Sign. A sign or outline lighting system already installed in the field that is designated for field conversion of the illumination system with a retrofit kit. (600) (CMP-18) ENHANCED CONTENT Collapse An existing electric sign that is being updated with new lighting components is referred to as the host sign in the installation instructions associated with a sign-specific retrofit kit. This definition correlates with the use of the term host sign in ANSI/UL 879A, Standard for LED Sign and Sign Retrofit Kits. Hydromassage Bathtub. 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. (680) (CMP-17) 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. (CMP-1) Informational Note: Some examples of ways to determine suitability of equipment for a specific purpose, environment, or application include investigations by a qualified testing laboratory (listing and labeling), an inspection agency, or other organizations concerned with product evaluation. In Sight From (Within Sight From) (Within Sight). Equipment that is visible and not more than 15 m (50 ft) distant from other equipment is in sight from that other equipment. (CMP-1) Informational Note: See 110.29 for additional information. Increased Safety “e”. Type of protection applied to electrical equipment that does not produce arcs or sparks in normal service and under specified abnormal conditions, in which additional measures are applied to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks. (CMP-14) Informational Note: See ANSI/UL 60079-7, Explosive Atmospheres — Part 7: Equipment Protection by Increased Safety “e”, for additional information. Induction Heating (Induction Melting) (Induction Welding). The heating, melting, or welding of a nominally conductive material due to its own I2R losses when the material is placed in a varying electromagnetic field. (665) (CMP-12) ENHANCED CONTENT Collapse Induction and dielectric heating methods are used for ovens, furnaces, and industrial equipment where pieces of material are heated by a rapidly alternating magnetic or electric field. Industrial Control Panel. 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. (CMP-11) Informational Note: The industrial control panel does not include the controlled equipment. Industrial Installation, Supervised. (Supervised Industrial Installation) The industrial portions of a facility where all of the following conditions are met: Conditions of maintenance and engineering supervision ensure that only qualified persons monitor and service the system. The premises wiring system has 2500 kVA or greater of load used in industrial process(es), manufacturing activities, or both, as calculated in accordance with Article 220. The premises has at least one service or feeder that is more than 150 volts to ground and more than 300 volts phase-to-phase. This definition excludes installations in buildings used by the industrial facility for offices, warehouses, garages, machine shops, and recreational facilities that are not an integral part of the industrial plant, substation, or control center. (240) (CMP-10) ENHANCED CONTENT Collapse All process or manufacturing loads from each low-, medium-, and high-voltage system can be added together to satisfy the load requirement. Loads not associated with manufacturing or processing cannot be used to meet the 2500-kilovolt-ampere minimum requirement. Loads are calculated in accordance with Article 220. Part VIII of Article 240 does not apply to electrical systems operating at over 1000 volts, nominal, or to electrical systems that serve separate facilities — such as offices, warehouses, garages, machine shops, or recreational buildings — that are not a part of the manufacturing or industrial process. Information Technology Equipment (ITE). 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 and do not process communications circuits. (CMP-12) Informational Note: See UL 60950-1, Information Technology Equipment — Safety — Part 1: General Requirements, or UL 62368-1, Audio/Video Information and Communication Technology Equipment Part 1: Safety Requirements, for information on listing requirements for both information technology equipment and communications equipment. Information Technology Equipment Room. A room within the information technology equipment area that contains the information technology equipment. [75:3.3.15] (CMP-12) Innerduct. A nonmetallic raceway placed within a larger raceway. (CMP-16) Insulated Bus Pipe (IBP). A cylindrical solid or hollow conductor with a solid insulation system, having conductive grading layers and a grounding layer imbedded in the insulation, and provided with an overall covering of insulating or metallic material. IBP is also referred to as tubular covered conductor (TCC). (CMP-8) Insulated Bus Pipe System. An assembly that includes bus pipe, connectors, fittings, mounting structures, and other fittings and accessories. (CMP-8) Insulating End. An insulator designed to electrically insulate the end of a flat conductor cable (Type FCC). (324) (CMP-6) Interactive Mode. The operating mode for power production equipment or microgrids that operate in parallel with and are capable of delivering energy to an electric power production and distribution network or other primary source. (CMP-4) Informational Note: Interactive mode is an operational mode of both interactive systems and of equipment such as interactive inverters. Interrupting Rating. The highest current at rated voltage that a device is identified to interrupt under standard test conditions. (CMP-10) Informational Note: Equipment intended to interrupt current at other than fault levels may have its interrupting rating implied in other ratings, such as horsepower or locked rotor current. ENHANCED CONTENT Collapse Interrupting ratings are essential for the coordination of electrical systems. The exhibit below depicts the label of a 225-ampere frame circuit breaker, showing the interrupting capacity ratings. See the definition of short-circuit current rating. (Courtesy of Eaton) See also 110.9, 240.60(C), 240.83(C), and 240.86, which deal specifically with interrupting ratings. Intersystem Bonding Termination (IBT). A device that provides a means for connecting intersystem bonding conductors for communications systems to the grounding electrode system. (CMP-16) ENHANCED CONTENT Collapse An intersystem bonding termination is a dedicated location for terminating the equipment grounding conductors required in Chapter 8 and 770.93 to the service, building, or structure’s grounding electrode system. Intrinsic Safety “i”. Type of protection where any spark or thermal effect is incapable of causing ignition of a mixture of flammable or combustible material in air under prescribed test conditions. (CMP-14) Informational Note: See ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations; and ANSI/UL 60079-11, Explosive Atmospheres — Part 11: Equipment Protection by Intrinsic Safety “i”, for additional information. Intrinsically Safe Apparatus. Apparatus in which all the circuits are intrinsically safe. (CMP-14) Informational Note No. 1: See ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations, and ANSI/UL 60079-11, Explosive Atmospheres — Part 11: Equipment Protection by Intrinsic Safety “i”, for additional information. Informational Note No. 2: See ANSI/ISA RP 12.06.01, Recommended Practice for Wiring Methods for Hazardous (Classified) Locations Instrumentation — Part 1: Intrinsic Safety, for installation information. Intrinsically Safe Circuit. A circuit in which any spark or thermal effect is incapable of causing ignition of a mixture of flammable or combustible material in air under prescribed test conditions. (CMP-14) Informational Note: See ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations, and ANSI/UL 60079-11, Explosive Atmospheres — Part 11: Equipment Protection by Intrinsic Safety “i”, for test conditions. ENHANCED CONTENT Collapse Due to its physical and electrical characteristics, an intrinsically safe (IS) circuit does not develop, under normal or abnormal operating conditions, sufficient electrical energy (millijoules) in an arc or spark to cause ignition or sufficient thermal energy resulting from an overload condition to cause the temperature of the installed circuit to exceed the ignition temperature of a specified gas or vapor. An abnormal condition can occur due to damage, failure of electrical components, excessive voltage, or improper adjustment or maintenance of the equipment. Abnormal conditions are mitigated by associated apparatus such as an IS barrier, an example of which is shown below. (Courtesy of Pepperl+Fuchs, Inc.) Intrinsically Safe Circuits, Different. (Different Intrinsically Safe Circuits) Intrinsically safe circuits in which the possible interconnections have not been evaluated and identified as intrinsically safe. (CMP-14) Informational Note: See ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations, and ANSI/UL 60079-11, Explosive Atmospheres — Part 11: Equipment Protection by Intrinsic Safety “i”, for additional information. Intrinsically Safe System. An assembly of interconnected intrinsically safe apparatus, associated apparatus, and interconnecting cables, in which those parts of the system that might be used in hazardous (classified) locations are intrinsically safe circuits. (CMP-14) Informational Note No. 1: An intrinsically safe system might include more than one intrinsically safe circuit. Informational Note No. 2: See ANSI/UL 913, Intrinsically Safe Apparatus and Associated Apparatus for Use in Class I, II, and III, Division 1, Hazardous (Classified) Locations; ANSI/UL 60079-11, Explosive Atmospheres — Part 11: Equipment Protection by Intrinsic Safety “i”; and ANSI/UL 60079-25, Explosive Atmospheres — Part 25: Intrinsically Safe Electrical Systems, for additional information. Informational Note No. 3: See ANSI/ISA RP 12.06.01, Recommended Practice for Wiring Methods for Hazardous (Classified) Locations Instrumentation — Part 1: Intrinsic Safety, for installation information. Invasive Procedure. Any procedure that penetrates the protective surfaces of a patient’s body (i.e., skin, mucous membrane, cornea) and that is performed with an aseptic field (procedural site). [Not included in this category are placement of peripheral intravenous needles or catheters used to administer fluids and/or medications, gastrointestinal endoscopies (i.e., sigmoidoscopies), insertion of urethral catheters, and other similar procedures.] [99:3.3.91] (517) (CMP-15) Inverter. Equipment that changes dc to ac. (CMP-4) Inverter, Interactive. (Interactive Inverter) Inverter equipment having the capability to operate only in interactive mode. (CMP-13) ENHANCED CONTENT Collapse The most common interactive inverters are string inverters and microinverters. String inverters typically are connected to a number of photovoltaic (PV) modules. Microinverters usually are connected to a single module. If microinverters are used in an installation, each module will have its own microinverter. Both string inverters and microinverters can be interactive. Inverter, Multimode. (Multimode Inverter) Inverter equipment capable of operating in both interactive and island modes. (CMP-4) Inverter, Stand-alone. (Stand-alone Inverter) Inverter equipment having the capabilities to operate only in island mode. (CMP-4) Inverter Input Circuit. Conductors connected to the dc input of an inverter. (CMP-13) Inverter Output Circuit. Conductors connected to the ac output of an inverter. (CMP-13) Inverter Utilization Output Circuit. Conductors between the multimode or stand-alone inverter and utilization equipment. (706) (CMP-13) Irrigation Machine. An electrically driven or controlled machine, with one or more motors, not hand-portable, and used primarily to transport and distribute water for agricultural purposes. (675) (CMP-7) Irrigation Machine, Center Pivot. (Center Pivot Irrigation Machine) A multimotored irrigation machine that revolves around a central pivot and employs alignment switches or similar devices to control individual motors. (675) (CMP-7) Island Mode. The operating mode for power production equipment or microgrids that allows energy to be supplied to loads that are disconnected from an electric power production and distribution network or other primary power source. (CMP-4) Isolated (as applied to location). Not readily accessible to persons unless special means for access are used. (CMP-1) Isolated Power System. A system comprising an isolation transformer or its equivalent, a line isolation monitor, and its ungrounded circuit conductors. [99:3.3.93] (517) (CMP-15) Isolation Transformer. A transformer of the multiple-winding type, with the primary and secondary windings physically separated, that inductively couples its ungrounded secondary winding to the grounded feeder system that energizes its primary winding. [99:3.3.94] (517) (CMP-15) Kitchen. An area with a sink and permanent provisions for food preparation and cooking. (CMP-2) Labeled. 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) Informational Note: If a listed product is of such a size, shape, material, or surface texture that it is not possible to apply legibly the complete label to the product, the complete label may appear on the smallest unit container in which the product is packaged. ENHANCED CONTENT Collapse Equipment and conductors required or permitted by the NEC are acceptable only if they have been approved for a specific environment or application by the AHJ as stated in 110.2. Listing or labeling by a qualified testing laboratory provides a basis for approval. See also 90.7 regarding the examination of equipment for safety. Laundry Area. An area containing or designed to contain a laundry tray, clothes washer, or clothes dryer. (CMP-2) Leakage-Current Detector-Interrupter (LCDI). A device provided in a power supply cord or cord set that senses leakage current flowing between or from the cord conductors and interrupts the circuit at a predetermined level of leakage current. (440) (CMP-11) ENHANCED CONTENT Collapse Opening of the circuit is accomplished through the use of electronic switching or by “air-break” contacts. The circuit remains open until the cause of the leakage current is eliminated or the protection device is manually reset. Leakage-current detector-interrupter protection is one of the permitted methods for the power supply cord or cord set of a room air conditioner specified in 440.65. LED Sign Illumination System. A complete lighting system for use in signs and outline lighting consisting of light-emitting diode (LED) light sources, power supplies, wire, and connectors to complete the installation. (600) (CMP-18) Legally Required Standby Systems. Those systems required and so classed as legally required standby by municipal, state, federal, or other codes or by any governmental agency having jurisdiction. These systems are intended to automatically supply power to selected loads (other than those classed as emergency systems) in the event of failure of the normal source. (CMP-13) Life Safety Branch. A system of feeders and branch circuits supplying power for lighting, receptacles, and equipment essential for life safety that is automatically connected to alternate power sources by one or more transfer switches during interruption of the normal power source. [99:3.3.97] (517) (CMP-15) Lighting Assembly, Cord-and-Plug-Connected. (Cord-and-Plug-Connected Lighting Assembly) 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. (680) (CMP-17) Lighting Assembly, Through-Wall. (Through-Wall Lighting Assembly) 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. (680) (CMP-17) Lighting Outlet. An outlet intended for the direct connection of a lampholder or luminaire. (CMP-18) Lighting Track. (Track Lighting) 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) Limited Care Facility. A building or portion of a building used on a 24-hour basis for the housing of four or more persons who are incapable of self-preservation because of age; physical limitation due to accident or illness; or limitations such as intellectual disability/developmental disability, mental illness, or chemical dependency. [101:3.3.93.2] (CMP-15) Limited Finishing Workstation. A power-ventilated apparatus that is capable of confining the vapors, mists, residues, dusts, or deposits that are generated by a limited spray application process. Suc