Chapter stringclasses 6 values | Reference stringlengths 1 17 | Body stringlengths 62 23.1k | URL stringlengths 26 42 |
|---|---|---|---|
Chaptewr 5 Special Occupancies | 502.130(A)(3) | Pendant luminaires shall be suspended by threaded rigid metal conduit stems, by threaded steel intermediate metal conduit stems, by chains with approved fittings, or by other approved means. For rigid stems longer than 300 mm (12 in.), permanent and effective bracing against lateral displacement shall be provided at a level not more than 300 mm (12 in.) above the lower end of the stem, or flexibility in the form of a fitting or a flexible connector listed for the location shall be provided not more than 300 mm (12 in.) from the point of attachment to the supporting box or fitting. Threaded joints shall be provided with set screws or other effective means to prevent loosening. Where wiring between an outlet box or fitting and a pendant luminaire is not enclosed in conduit, flexible cord listed for hard usage shall be permitted to be used in accordance with 502.10(A)(2)(5). Flexible cord shall not serve as the supporting means for a luminaire. [502.130(A)(3)](https://2023.antflix.net#502.130(A)(3)) | https://2023.antflix.net#502.130(A)(3) |
Chaptewr 5 Special Occupancies | 502.130(A)(4) | Boxes, box assemblies, or fittings used for the support of luminaires shall be identified for Class II locations. [502.130(A)(4)](https://2023.antflix.net#502.130(A)(4)) | https://2023.antflix.net#502.130(A)(4) |
Chaptewr 5 Special Occupancies | 502.130(B) | In Class II, Division 2 locations, luminaires shall comply with 502.130(B)(1) through (B)(5). [502.130(B)](https://2023.antflix.net#502.130(B)) | https://2023.antflix.net#502.130(B) |
Chaptewr 5 Special Occupancies | 502.130(B)(1) | Portable lighting equipment shall be identified for the location. They shall be clearly marked to indicate the maximum wattage of lamps for which they are designed. [502.130(B)(1)](https://2023.antflix.net#502.130(B)(1)) | https://2023.antflix.net#502.130(B)(1) |
Chaptewr 5 Special Occupancies | 502.130(B)(2) | Luminaires for fixed lighting shall be provided with enclosures that are dusttight or otherwise identified for the location. Each luminaire shall be clearly marked to indicate the maximum wattage of the lamp that shall be permitted without exceeding an exposed surface temperature in accordance with 500.8(D)(2) under normal conditions of use. [502.130(B)(2)](https://2023.antflix.net#502.130(B)(2)) | https://2023.antflix.net#502.130(B)(2) |
Chaptewr 5 Special Occupancies | 502.130(B)(3) | Luminaires for fixed lighting shall be protected from physical damage by suitable guards or by location. [502.130(B)(3)](https://2023.antflix.net#502.130(B)(3)) | https://2023.antflix.net#502.130(B)(3) |
Chaptewr 5 Special Occupancies | 502.130(B)(4) | Pendant luminaires shall be suspended by threaded rigid metal conduit stems, by threaded steel intermediate metal conduit stems, by chains with approved fittings, or by other approved means. For rigid stems longer than 300 mm (12 in.), permanent and effective bracing against lateral displacement shall be provided at a level not more than 300 mm (12 in.) above the lower end of the stem, or flexibility in the form of an identified fitting or a flexible connector shall be provided not more than 300 mm (12 in.) from the point of attachment to the supporting box or fitting. Where wiring between an outlet box or fitting and a pendant luminaire is not enclosed in conduit, flexible cord listed for hard usage shall be permitted if terminated with a listed cord connector that maintains the protection technique. Flexible cord shall not serve as the supporting means for a luminaire. [502.130(B)(4)](https://2023.antflix.net#502.130(B)(4)) | https://2023.antflix.net#502.130(B)(4) |
Chaptewr 5 Special Occupancies | 502.130(B)(5) | Starting and control equipment for electric-discharge lamps shall comply with the requirements of 502.120(B). [502.130(B)(5)](https://2023.antflix.net#502.130(B)(5)) | https://2023.antflix.net#502.130(B)(5) |
Chaptewr 5 Special Occupancies | 502.135(A) | In Class II, Division 1 locations, all utilization equipment shall be identified for the location. [502.135(A)](https://2023.antflix.net#502.135(A)) | https://2023.antflix.net#502.135(A) |
Chaptewr 5 Special Occupancies | 502.135(B) | In Class II, Division 2 locations, all utilization equipment shall comply with 502.135(B)(1) through (B)(4). [502.135(B)](https://2023.antflix.net#502.135(B)) | https://2023.antflix.net#502.135(B) |
Chaptewr 5 Special Occupancies | 502.135(B)(1) | Electrically heated utilization equipment shall be identified for the location. Exception: Metal-enclosed radiant heating panel equipment shall be permitted to be dusttight and marked in accordance with 500.8(C). [502.135(B)(1)](https://2023.antflix.net#502.135(B)(1)) | https://2023.antflix.net#502.135(B)(1) |
Chaptewr 5 Special Occupancies | 502.135(B)(2) | Motors of motor-driven utilization equipment shall comply with 502.125(B). [502.135(B)(2)](https://2023.antflix.net#502.135(B)(2)) | https://2023.antflix.net#502.135(B)(2) |
Chaptewr 5 Special Occupancies | 502.135(B)(3) | Enclosures for switches, circuit breakers, and fuses shall comply with 502.115(B). [502.135(B)(3)](https://2023.antflix.net#502.135(B)(3)) | https://2023.antflix.net#502.135(B)(3) |
Chaptewr 5 Special Occupancies | 502.135(B)(4) | Transformers, solenoids, impedance coils, and resistors shall comply with 502.120(B). [502.135(B)(4)](https://2023.antflix.net#502.135(B)(4)) | https://2023.antflix.net#502.135(B)(4) |
Chaptewr 5 Special Occupancies | 502.140(A) | Flexible cords used in Class II locations shall be permitted as follows: For connection between portable lighting equipment or other portable utilization equipment and the fixed portion of its supply circuit. The flexible cord shall be attached to the utilization equipment with a cord connector listed for the protection technique of the equipment wiring compartment. An attachment plug in accordance with 502.145 shall be employed.Where flexible cord is permitted by 502.10(A)(2) for fixed and mobile electrical utilization equipment; where the flexible cord is protected by location or by a suitable guard from damage; and only in a restricted industrial establishment.For electric submersible pumps with means for removal without entering the wet-pit. The extension of the flexible cord within a suitable raceway between the wet-pit and the power source shall be permitted.For electric mixers intended for travel into and out of open-type mixing tanks or vats.For temporary portable assemblies consisting of receptacles, switches, and other devices that are not considered portable utilization equipment but are individually listed for the location. [502.140(A)](https://2023.antflix.net#502.140(A)) | https://2023.antflix.net#502.140(A) |
Chaptewr 5 Special Occupancies | 502.140(B) | Where flexible cords are used, the cords shall comply with all of the following: Be of a type listed for extra-hard usage.Exception to (1): Flexible cord listed for hard usage as permitted by 502.130(A)(3) and (B)(4).Contain, in addition to the conductors of the circuit, an equipment grounding conductor complying with 400.23.Be supported by clamps or by other suitable means in such a manner that there will be no tension on the terminal connections.In Division 1 locations, the cord shall be terminated with a cord connector listed for the location or a listed cord connector installed with a seal listed for the location. In Division 2 locations, the cord shall be terminated with a listed dusttight cord connector.Be of continuous length. Where 502.140(A)(5) is applied, cords shall be of continuous length from the power source to the temporary portable assembly and from the temporary portable assembly to the utilization equipment. [502.140(B)](https://2023.antflix.net#502.140(B)) | https://2023.antflix.net#502.140(B) |
Chaptewr 5 Special Occupancies | 502.145 | Receptacles and attachment plugs shall be identified for the location. [502.145](https://2023.antflix.net#502.145) | https://2023.antflix.net#502.145 |
Chaptewr 5 Special Occupancies | 502.145(A)(1) | In Class II, Division 1 locations, receptacles shall be part of the premises wiring. [502.145(A)(1)](https://2023.antflix.net#502.145(A)(1)) | https://2023.antflix.net#502.145(A)(1) |
Chaptewr 5 Special Occupancies | 502.145(A)(2) | Attachment plugs shall be of the type that provides for connection to the equipment grounding conductor of the flexible cord. [502.145(A)(2)](https://2023.antflix.net#502.145(A)(2)) | https://2023.antflix.net#502.145(A)(2) |
Chaptewr 5 Special Occupancies | 502.145(B)(1) | In Class II, Division 2 locations, receptacles shall be part of the premises wiring. [502.145(B)(1)](https://2023.antflix.net#502.145(B)(1)) | https://2023.antflix.net#502.145(B)(1) |
Chaptewr 5 Special Occupancies | 502.145(B)(2) | Attachment plugs shall be of the type that provides for connection to the equipment grounding conductor of the flexible cord. [502.145(B)(2)](https://2023.antflix.net#502.145(B)(2)) | https://2023.antflix.net#502.145(B)(2) |
Chaptewr 5 Special Occupancies | 502.150(A) | In Class II, Division 1 locations, signaling, alarm, remote-control, and communications systems; and meters, instruments, and relays shall comply with 502.150(A)(1) through (A)(3). [502.150(A)](https://2023.antflix.net#502.150(A)) | https://2023.antflix.net#502.150(A) |
Chaptewr 5 Special Occupancies | 502.150(A)(1) | Enclosures containing contacts shall comply with the requirements of 502.150(A)(1)(a) or (A)(1)(b). Switches, circuit breakers, relays, contactors, fuses, and current-breaking contacts for bells, horns, howlers, sirens, and other devices in which sparks or arcs might be produced shall be provided with enclosures identified for the location.Where current-breaking contacts are immersed in oil or where the interruption of current occurs within a chamber sealed against the entrance of dust, enclosures shall be permitted to be of the general-purpose type. [502.150(A)(1)](https://2023.antflix.net#502.150(A)(1)) | https://2023.antflix.net#502.150(A)(1) |
Chaptewr 5 Special Occupancies | 502.150(A)(2) | Enclosures containing resistors shall comply with the requirements of 502.150(A)(2)(a) or (A)(2)(b). Resistors, transformers, choke coils, rectifiers, thermionic tubes, and other heat-generating equipment shall be provided with enclosures identified for the location.Where resistors or similar equipment are immersed in oil or enclosed in a chamber sealed against the entrance of dust, enclosures shall be permitted to be of the general-purpose type. [502.150(A)(2)](https://2023.antflix.net#502.150(A)(2)) | https://2023.antflix.net#502.150(A)(2) |
Chaptewr 5 Special Occupancies | 502.150(A)(3) | Motors, generators, and other rotating electrical machinery shall comply with 502.125(A). [502.150(A)(3)](https://2023.antflix.net#502.150(A)(3)) | https://2023.antflix.net#502.150(A)(3) |
Chaptewr 5 Special Occupancies | 502.150(B) | In Class II, Division 2 locations, signaling, alarm, remote-control, and communications systems; and meters, instruments, and relays shall comply with 502.150(B)(1) through (B)(4). [502.150(B)](https://2023.antflix.net#502.150(B)) | https://2023.antflix.net#502.150(B) |
Chaptewr 5 Special Occupancies | 502.150(B)(1) | Enclosures for contacts shall comply with the requirements of 502.150(B)(1)(a) or (B)(1)(b). Contacts shall comply with the requirements of 502.150(A)(1) or be installed in enclosures that are dusttight or otherwise identified for the location.Enclosures in nonincendive circuits shall be permitted to be of the general-purpose type. [502.150(B)(1)](https://2023.antflix.net#502.150(B)(1)) | https://2023.antflix.net#502.150(B)(1) |
Chaptewr 5 Special Occupancies | 502.150(B)(2) | The windings and terminal connections of transformers, choke coils, and similar equipment shall comply with 502.120(B)(2). [502.150(B)(2)](https://2023.antflix.net#502.150(B)(2)) | https://2023.antflix.net#502.150(B)(2) |
Chaptewr 5 Special Occupancies | 502.150(B)(3) | Resistors, resistance devices, thermionic tubes, rectifiers, and similar equipment shall comply with 502.120(B)(3). [502.150(B)(3)](https://2023.antflix.net#502.150(B)(3)) | https://2023.antflix.net#502.150(B)(3) |
Chaptewr 5 Special Occupancies | 502.150(B)(4) | Motors, generators, and other rotating electrical machinery shall comply with 502.125(B). [502.150(B)(4)](https://2023.antflix.net#502.150(B)(4)) | https://2023.antflix.net#502.150(B)(4) |
Chaptewr 5 Special Occupancies | 502.150(B)(5) | To facilitate replacements, process control instruments shall be permitted to be connected through flexible cord, attachment plug, and receptacle if all of the following conditions apply; Attachment plug and receptacle are listed for use in Class II, Division 2 locations, and listed for use with flexible cords.Exception No. 1 to (1): A Class II, Division 2 listing shall not be required if the circuit involves only nonincendive field wiring.Exception No. 2 to (1): In restricted industrial establishments, the Class II, Division 2 listing shall not be required when the requirements of 502.150(B)(5)(2), (B)(5)(3), and (B)(5)(4) are satisfied and the receptacle carries a label warning against plugging or unplugging when energized.The flexible cord does not exceed 900 mm (3 ft), is of a type listed for extra-hard usage, or, if listed for hard usage, is protected by location.Only necessary receptacles are provided.Unless the attachment plug and receptacle are interlocked mechanically or electrically, or otherwise designed so that they cannot be separated when the contacts are energized, and the contacts cannot be energized when the plug and socket outlet are separated, a switch complying with 502.115(B) is provided so that the attachment plug or receptacle is not depended on to interrupt current.Exception to (4): The switch shall not be required if the circuit is nonincendive field wiring. [502.150(B)(5)](https://2023.antflix.net#502.150(B)(5)) | https://2023.antflix.net#502.150(B)(5) |
Chaptewr 5 Special Occupancies | 503.1 | This article covers the requirements for electrical and electronic equipment and wiring for all voltages in Class III, Division 1 and Division 2 locations where fire or explosion hazards might exist due to nonmetal combustible fibers/flyings or ignitible fibers/flyings. [503.1](https://2023.antflix.net#503.1) | https://2023.antflix.net#503.1 |
Chaptewr 5 Special Occupancies | 503.5 | Equipment installed in Class III locations shall be able to function at full rating without developing surface temperatures high enough to cause excessive dehydration or gradual carbonization of accumulated fibers/flyings. Informational Note No. 1: See NFPA 505, Fire Safety Standard for Powered Industrial Trucks Including Type Designations, Areas of Use, Conversions, Maintenance, and Operations, for information on electric trucks. Informational Note No. 2: Organic material that is carbonized or excessively dry is highly susceptible to spontaneous ignition. [503.5](https://2023.antflix.net#503.5) | https://2023.antflix.net#503.5 |
Chaptewr 5 Special Occupancies | 503.6 | Equipment listed and marked in accordance with 506.9(C)(2) for Zone 20 locations and with a temperature marking in accordance with 500.8(D)(3) shall be permitted in Class III, Division 1 locations. Equipment listed and marked in accordance with 506.9(C)(2) for Zone 20, Zone 21, or Zone 22 locations and with a temperature marking in accordance with 500.8(D)(3) shall be permitted in Class III, Division 2 locations. [503.6](https://2023.antflix.net#503.6) | https://2023.antflix.net#503.6 |
Chaptewr 5 Special Occupancies | 503.10 | Wiring methods shall comply with 503.10(A) or (B). Informational Note: See Article 100 for the definition of restricted industrial establishment [as applied to hazardous (classified) locations]. [503.10](https://2023.antflix.net#503.10) | https://2023.antflix.net#503.10 |
Chaptewr 5 Special Occupancies | 503.10(A)(1) | In Class III, Division 1 locations, the following wiring methods shall be permitted: Rigid metal conduit (RMC), PVC conduit, RTRC conduit, intermediate metal conduit (IMC), electrical metallic tubing (EMT), dusttight wireways, or Type MC or Type MI cable with listed termination fittings.Type PLTC cable or Type PLTC-ER cable used in Class 2 and Class 3 circuits, including installation in cable tray systems. The cable shall be terminated with listed fittings. Type PLTC-ER cable shall include an equipment grounding conductor in addition to a drain wire that might be present.Type ITC cable or Type ITC-ER cable as permitted in 335.4 and terminated with listed fittings. Type ITC-ER cable shall include an equipment grounding conductor in addition to a drain wire.Type MV, Type TC, or Type TC-ER cable, including installation in cable tray systems. Type TC-ER cable shall include an equipment grounding conductor in addition to a drain wire that might be present. The cable shall be terminated with listed fittings.Cablebus.In restricted industrial establishments, listed Type P cable with metal braid armor, with an overall jacket, that is terminated with fittings listed for the location, and installed in accordance with Part II of Article 337. If installed in ladder, ventilated trough, or ventilated channel cable trays, cables shall be installed in a single layer, with a space not less than the larger cable diameter between the two adjacent cables unless otherwise protected against dust buildup resulting in increased heat.Informational Note No. 1: See UL 1309A, Outline of Investigation for Cable for Use in Mobile Installations, for information on construction, testing, and marking of Type P cable.Informational Note No. 2: See ANSI/UL 2225, Cables and Cable-Fittings for Use in Hazardous (Classified) Locations, for information on construction, testing, and marking of cable fittings. [503.10(A)(1)](https://2023.antflix.net#503.10(A)(1)) | https://2023.antflix.net#503.10(A)(1) |
Chaptewr 5 Special Occupancies | 503.10(A)(2) | All boxes and fittings shall be dust-tight. [503.10(A)(2)](https://2023.antflix.net#503.10(A)(2)) | https://2023.antflix.net#503.10(A)(2) |
Chaptewr 5 Special Occupancies | 503.10(A)(3) | Where flexible connections are necessary, one or more of the following shall be permitted: Dusttight flexible connectorsLiquidtight flexible metal conduit (LFMC) with listed fittingsLiquidtight flexible nonmetallic conduit (LFNC) with listed fittings and bonded in accordance with 503.30(B)Interlocked armor Type MC cable having an overall jacket of suitable polymeric material and installed with listed dusttight termination fittingsFlexible cord in accordance with 503.140For elevator use, an identified elevator cable of Type EO, Type ETP, or Type ETT, shown under the "use" column in Table 400.4 for "hazardous (classified) locations" and terminated with listed dusttight fittingsIn restricted industrial establishments, listed Type P cable with metal braid armor, with an overall jacket, that is terminated with fittings listed for the location and installed in accordance with Part II of Article 337Informational Note: See UL 1309A, Outline of Investigation for Cable for Use in Mobile Installations, for information on construction, testing, and marking of Type P cable. [503.10(A)(3)](https://2023.antflix.net#503.10(A)(3)) | https://2023.antflix.net#503.10(A)(3) |
Chaptewr 5 Special Occupancies | 503.10(A)(4) | Nonincendive field wiring shall be permitted using any of the wiring methods permitted for unclassified locations. Nonincendive field wiring systems shall be installed in accordance with the control drawing(s). Simple apparatus, not shown on the control drawing, shall be permitted in a nonincendive field wiring circuit if the simple apparatus does not interconnect the nonincendive field wiring circuit to any other circuit. Informational Note: See Article 100 for the definition of simple apparatus. Separate nonincendive field wiring circuits shall be installed in accordance with one of the following:In separate cablesIn multiconductor cables where the conductors of each circuit are within a grounded metal shieldIn multiconductor cables where the conductors of each circuit have insulation with a minimum thickness of 0.25 mm (0.01 in.) [503.10(A)(4)](https://2023.antflix.net#503.10(A)(4)) | https://2023.antflix.net#503.10(A)(4) |
Chaptewr 5 Special Occupancies | 503.10(B) | Wiring methods in Class III. Division 2 locations shall be in accordance with the following: The wiring shall comply with 503.10(A).In sections, compartments, or areas that do not contain machinery and are used solely for storage, open wiring on insulators shall be permitted where installed in accordance with Part II of Article 398, including the condition required by 398.15(C) that protection be provided where conductors are not run in roof spaces and are well out of reach of sources of physical damage. [503.10(B)](https://2023.antflix.net#503.10(B)) | https://2023.antflix.net#503.10(B) |
Chaptewr 5 Special Occupancies | 503.25 | There shall be no uninsulated exposed parts, such as electrical conductors, buses, terminals, or components, that operate at more than 30 volts (15 volts in wet locations). These parts shall additionally be protected by a protection technique according to 500.7(E), (F), or (G) that is suitable for the location. Exception: As provided in 503.155. [503.25](https://2023.antflix.net#503.25) | https://2023.antflix.net#503.25 |
Chaptewr 5 Special Occupancies | 503.30 | Regardless of the voltage of the electrical system, wiring systems and equipment shall comply with 503.30(A) and (B). [503.30](https://2023.antflix.net#503.30) | https://2023.antflix.net#503.30 |
Chaptewr 5 Special Occupancies | 503.30(A) | Wiring systems and equipment shall be grounded in accordance with Part I and Part VI of Article 250, as applicable. [503.30(A)](https://2023.antflix.net#503.30(A)) | https://2023.antflix.net#503.30(A) |
Chaptewr 5 Special Occupancies | 503.30(B) | Bonding shall comply with Part I and Part V of Article 250, as applicable, and 503.30(B)(1) and (B)(2). [503.30(B)](https://2023.antflix.net#503.30(B)) | https://2023.antflix.net#503.30(B) |
Chaptewr 5 Special Occupancies | 503.30(B)(1) | Bonding shall comply with 503.30(B)(1)(a) and (B)(2)(b). The locknut-bushing and double-locknut types of contacts shall not be depended on for bonding purposes, but bonding jumpers with identified fittings or other approved means of bonding shall be used. These bonding means shall apply to all metal raceways, fittings, boxes, cable trays, and enclosures, and other parts of raceway systems between hazardous (classified) locations and the point of grounding for service equipment or point of grounding for a separately derived system. Metal struts, angles, or channels provided for support and mechanical or physical protection as permitted in 335.4(5), 336.10(7)(c), or 722.135(C) shall be bonded in accordance with 250.102.Where the branch-circuit overcurrent protection is located on the load side of the disconnecting means, the specific bonding means shall be permitted to end at the nearest point where the grounded circuit conductor and the grounding electrode conductor are connected together on the line side of the building or structure disconnecting means as specified in 250.32(B). [503.30(B)(1)](https://2023.antflix.net#503.30(B)(1)) | https://2023.antflix.net#503.30(B)(1) |
Chaptewr 5 Special Occupancies | 503.30(B)(2) | Liquidtight flexible metal conduit shall comply with 503.30(B)(2)(a) and (B)(2)(b). Liquidtight flexible metal conduit shall include an equipment bonding jumper of the wire type in accordance with 250.102.In Class III locations, the bonding jumper shall not be required where all of the following conditions are met:Listed liquidtight flexible metal conduit 1.8 m (6 ft) or less in length, with fittings listed for grounding, is used.Overcurrent protection in the circuit is limited to 10 amperes or less.The load is part of a meter, instrument, or relay circuit. [503.30(B)(2)](https://2023.antflix.net#503.30(B)(2)) | https://2023.antflix.net#503.30(B)(2) |
Chaptewr 5 Special Occupancies | 503.100 | Transformers and capacitors shall comply with 502.100(B). [503.100](https://2023.antflix.net#503.100) | https://2023.antflix.net#503.100 |
Chaptewr 5 Special Occupancies | 503.115 | Switches, circuit breakers, motor controllers, and fuses, including pushbuttons, relays, and similar devices, shall be provided with dusttight enclosures. [503.115](https://2023.antflix.net#503.115) | https://2023.antflix.net#503.115 |
Chaptewr 5 Special Occupancies | 503.120 | Transformers, impedance coils, and resistors used as, or in conjunction with, control equipment for motors, generators, and appliances shall be provided with dusttight enclosures complying with the temperature limitations in 503.5. [503.120](https://2023.antflix.net#503.120) | https://2023.antflix.net#503.120 |
Chaptewr 5 Special Occupancies | 503.125 | In Class III, Division 1 and Division 2 locations, motors, generators, and other rotating machinery shall be totally enclosed nonventilated, totally enclosed pipe ventilated, or totally enclosed fan cooled. Exception: In locations where, in the judgment of the authority having jurisdiction, only moderate accumulations of ignitible fibers/flyings are likely to collect on, in, or in the vicinity of a rotating electrical machine and where such machine is readily accessible for routine cleaning and maintenance, one of the following shall be permitted: (1) Self-cleaning textile motors of the squirrel-cage type (2) Standard open-type machines without sliding contacts or centrifugal or other types of switching mechanisms, including motor overload devices (3) Standard open-type machines having such contacts, switching mechanisms, or resistance devices enclosed within tight housings without ventilating or other openings [503.125](https://2023.antflix.net#503.125) | https://2023.antflix.net#503.125 |
Chaptewr 5 Special Occupancies | 503.128 | Ventilating pipes for motors, generators, or other rotating electrical machinery, or for enclosures for electric equipment, shall be of metal not less than 0.53 mm (0.021 in.) in thickness, or of equally substantial noncombustible material, and shall comply with the following:Lead directly to a source of clean air outside of buildingsBe screened at the outer ends to prevent the entrance of small animals or birdsBe protected against physical damage and against rusting or other corrosive influencesVentilating pipes shall be sufficiently tight, including their connections, to prevent the entrance of appreciable quantities of fibers/flyings into the ventilated equipment or enclosure and to prevent the escape of sparks, flame, or burning material that might ignite accumulations of fibers/flyings or combustible material in the vicinity. For metal pipes, lock seams and riveted or welded joints shall be permitted; and tight-fitting slip joints shall be permitted where some flexibility is necessary, as at connections to motors. [503.128](https://2023.antflix.net#503.128) | https://2023.antflix.net#503.128 |
Chaptewr 5 Special Occupancies | 503.130(A) | Luminaires for fixed lighting shall provide enclosures for lamps and lampholders that are designed to minimize entrance of fibers/flyings and to prevent the escape of sparks, burning material, or hot metal. Each luminaire shall be clearly marked to show the maximum wattage of the lamps that shall be permitted without exceeding an exposed surface temperature of 165°C (329°F) under normal conditions of use. [503.130(A)](https://2023.antflix.net#503.130(A)) | https://2023.antflix.net#503.130(A) |
Chaptewr 5 Special Occupancies | 503.130(B) | A luminaire that may be exposed to physical damage shall be protected by a suitable guard. [503.130(B)](https://2023.antflix.net#503.130(B)) | https://2023.antflix.net#503.130(B) |
Chaptewr 5 Special Occupancies | 503.130(C) | Pendant luminaires shall be suspended by stems of threaded rigid metal conduit, threaded intermediate metal conduit, threaded metal tubing of equivalent thickness, or by chains with approved fittings. For stems longer than 300 mm (12 in.), permanent and effective bracing against lateral displacement shall be provided at a level not more than 300 mm (12 in.) above the lower end of the stem, or flexibility in the form of an identified fitting or a flexible connector shall be provided not more than 300 mm (12 in.) from the point of attachment to the supporting box or fitting. [503.130(C)](https://2023.antflix.net#503.130(C)) | https://2023.antflix.net#503.130(C) |
Chaptewr 5 Special Occupancies | 503.130(D) | Portable lighting equipment shall be equipped with handles and protected with substantial guards. Lampholders shall be of the unswitched type with no provision for receiving attachment plugs. There shall be no exposed current-carrying metal parts, and all exposed non—current-carrying metal parts shall be grounded. In all other respects, portable lighting equipment shall comply with 503.130(A). [503.130(D)](https://2023.antflix.net#503.130(D)) | https://2023.antflix.net#503.130(D) |
Chaptewr 5 Special Occupancies | 503.135(A) | Electrically heated utilization equipment shall be identified for Class III locations. [503.135(A)](https://2023.antflix.net#503.135(A)) | https://2023.antflix.net#503.135(A) |
Chaptewr 5 Special Occupancies | 503.135(B) | Motors of motor-driven utilization equipment shall comply with 503.125. [503.135(B)](https://2023.antflix.net#503.135(B)) | https://2023.antflix.net#503.135(B) |
Chaptewr 5 Special Occupancies | 503.135(C) | Switches, circuit breakers, motor controllers, and fuses shall comply with 503.115. [503.135(C)](https://2023.antflix.net#503.135(C)) | https://2023.antflix.net#503.135(C) |
Chaptewr 5 Special Occupancies | 503.140 | Flexible cords shall comply with the following: Be of a type listed for extra-hard usageContain, in addition to the conductors of the circuit, an equipment grounding conductor complying with 400.23Be supported by clamps or other suitable means in such a manner that there will be no tension on the terminal connectionsBe terminated with a listed dusttight cord connector [503.140](https://2023.antflix.net#503.140) | https://2023.antflix.net#503.140 |
Chaptewr 5 Special Occupancies | 503.145 | Receptacles and attachment plugs shall be of the grounding type, shall be designed to minimize the accumulation or the entry of fibers/flyings, and shall prevent the escape of sparks or molten particles. Exception: In locations where, in the judgment of the authority having jurisdiction, only moderate accumulations of ignitible fibers/flyings are likely to collect in the vicinity of a receptacle, and where such receptacle is readily accessible for routine cleaning and mounted to minimize the entry of fibers/flyings, general-purpose grounding-type receptacles shall be permitted. [503.145](https://2023.antflix.net#503.145) | https://2023.antflix.net#503.145 |
Chaptewr 5 Special Occupancies | 503.150 | Signaling, alarm, remote-control, and local loudspeaker intercommunications systems shall comply with the requirements of this article regarding wiring methods, switches, transformers, resistors, motors, luminaires, and related components. [503.150](https://2023.antflix.net#503.150) | https://2023.antflix.net#503.150 |
Chaptewr 5 Special Occupancies | 503.155 | Where installed for operation over combustible fibers or accumulations of flyings, traveling cranes and hoists for material handling, traveling cleaners for textile machinery, and similar equipment shall comply with 503.155(A) through (D). [503.155](https://2023.antflix.net#503.155) | https://2023.antflix.net#503.155 |
Chaptewr 5 Special Occupancies | 503.155(A) | The power supply to contact conductors shall be electrically isolated from all other systems, ungrounded, and shall be equipped with an acceptable ground detector that gives an alarm and automatically de-energizes the contact conductors in case of a fault to ground or gives a visual and audible alarm as long as power is supplied to the contact conductors and the ground fault remains. [503.155(A)](https://2023.antflix.net#503.155(A)) | https://2023.antflix.net#503.155(A) |
Chaptewr 5 Special Occupancies | 503.155(B) | Contact conductors shall be located or guarded so as to be inaccessible to other than authorized persons and shall be protected against accidental contact with foreign objects. [503.155(B)](https://2023.antflix.net#503.155(B)) | https://2023.antflix.net#503.155(B) |
Chaptewr 5 Special Occupancies | 503.155(C) | Current collectors shall be arranged or guarded so as to confine normal sparking and prevent escape of sparks or hot particles. To reduce sparking, two or more separate surfaces of contact shall be provided for each contact conductor. Reliable means shall be provided to keep contact conductors and current collectors free of accumulations of lint or flyings. [503.155(C)](https://2023.antflix.net#503.155(C)) | https://2023.antflix.net#503.155(C) |
Chaptewr 5 Special Occupancies | 503.155(D) | Control equipment shall comply with 503.115 and 503.120. [503.155(D)](https://2023.antflix.net#503.155(D)) | https://2023.antflix.net#503.155(D) |
Chaptewr 5 Special Occupancies | 503.160 | Storage battery charging equipment shall be located in separate rooms built or lined with substantial noncombustible materials. The rooms shall be constructed to prevent the entrance of ignitible amounts of flyings or lint and shall be well ventilated. [503.160](https://2023.antflix.net#503.160) | https://2023.antflix.net#503.160 |
Chaptewr 5 Special Occupancies | 504.1 | This article covers the installation of intrinsically safe (I.S.) apparatus, wiring, and systems for hazardous (classified) locations. Informational Note: See ANSI/ISA RP 12.06.01, Recommended Practice for Wiring Methods for Hazardous (Classified) locations Instrumentation - Part 1: Intrinsic Safely, for additional information. [504.1](https://2023.antflix.net#504.1) | https://2023.antflix.net#504.1 |
Chaptewr 5 Special Occupancies | 504.3 | Except as modified by this article, all applicable articles of this Code shall apply. [504.3](https://2023.antflix.net#504.3) | https://2023.antflix.net#504.3 |
Chaptewr 5 Special Occupancies | 504.4 | All intrinsically safe apparatus and associated apparatus shall be listed. Exception: Simple apparatus, as described on the control drawing, shall not be required to be listed. [504.4](https://2023.antflix.net#504.4) | https://2023.antflix.net#504.4 |
Chaptewr 5 Special Occupancies | 504.10(A) | Intrinsically safe apparatus, associated apparatus, and other equipment shall be installed in accordance with the control drawing(s). A simple apparatus, whether or not shown on the control drawing(s), shall be permitted to be installed provided the simple apparatus does not interconnect intrinsically safe circuits. Informational Note No. 1: The control drawing identification is marked on the apparatus. Informational Note No. 2: Associated apparatus with a marked Um of less than 250 V may require additional overvoltage protection at the inputs to limit any possible fault voltages to less than the Um marked on the product. [504.10(A)](https://2023.antflix.net#504.10(A)) | https://2023.antflix.net#504.10(A) |
Chaptewr 5 Special Occupancies | 504.10(B) | Intrinsically safe apparatus shall be permitted to be installed in any hazardous (classified) location for which it has been identified. Associated apparatus shall be permitted to be installed in any hazardous (classified) location for which it has been identified. Simple apparatus shall be permitted to be installed in any hazardous (classified) location in accordance with 504.10(D). [504.10(B)](https://2023.antflix.net#504.10(B)) | https://2023.antflix.net#504.10(B) |
Chaptewr 5 Special Occupancies | 504.10(C) | General-purpose enclosures shall be permitted for intrinsically safe apparatus and associated apparatus unless otherwise specified in the manufacturer's documentation. [504.10(C)](https://2023.antflix.net#504.10(C)) | https://2023.antflix.net#504.10(C) |
Chaptewr 5 Special Occupancies | 504.10(D) | Simple apparatus shall be permitted to be installed in any hazardous (classified) location in which the maximum surface temperature of the simple apparatus does not exceed the ignition temperature of the flammable gases or vapors, flammable liquids, combustible dusts, or ignitible fibers/flyings present. The maximum surface temperature can be determined from the values of the output power from the associated apparatus or apparatus to which it is connected to obtain the temperature class. The temperature class can be determined by: Reference to Table 504.10(D)Calculation using the following equation: [504.10(D)] T = PoRth + Tamb where: T = surface temperature Po = output power marked on the associated apparatus or intrinsically safe apparatus Rth = thermal resistance of the simple apparatus Tamb = ambient temperature (normally 40°C) and reference Table 500.8(C)(4) In addition, components with a surface area smaller than 10 cm2 (excluding lead wires) may be classified as T5 if their surface temperature does not exceed 150°C.Table 504.10(D) Assessment for T4 Classification According to Component Size and Temperature Total Surface Area Excluding Lead Wires Requirement for T4 Classification <20 mm2 Surface temperature ≤275°C ≥20 mm2 ≤10 cm2 Surface temperature ≤200°C ≥20 mm2 Power not exceeding 1.3 W* *Based on 40°C ambient temperature. Reduce to 1.2 W with an ambient of 60°C or 1.0 W with 80°C ambient temperature. [504.10(D)](https://2023.antflix.net#504.10(D)) | https://2023.antflix.net#504.10(D) |
Chaptewr 5 Special Occupancies | 504.20 | Any of the wiring methods suitable for unclassified locations, including those covered by Chapter 7 and Chapter 8, shall be permitted for installing intrinsically safe apparatus. Sealing shall be as provided in 504.70, and separation shall be as provided in 504.30. [504.20](https://2023.antflix.net#504.20) | https://2023.antflix.net#504.20 |
Chaptewr 5 Special Occupancies | 504.30(A)(1) | Conductors of intrinsically safe circuits shall not be placed in any raceway, cable tray, or cable with conductors of any nonintrinsically safe circuit, unless they meet the requirements of one of the following methods: Separated from conductors of nonintrinsically safe circuits in accordance with one of the following:By a distance of at least 50 mm (2 in.) and securedBy a grounded metal partition that is 0.91 mm (0.0359 in) or thickerAn approved insulating partitionAll of the intrinsically safe circuit conductors or nonintrinsically safe circuit conductors are in Type MC cable, Type MI cable, or other approved grounded metal-sheathed or metal-clad cables where the sheathing or cladding is capable of carrying fault current to groundIn a Division 2 or Zone 2 location, installed in a raceway, cable tray, or cable along with nonincendive field wiring circuits when installed in accordance with 504.30(B)Where passing through a Division 2 or Zone 2 location to supply apparatus that is located in a Division 1, Zone 0 or Zone 1 location, installed in a raceway, cable tray, or cable along with nonincendive field wiring circuits when installed in accordance with 504.30(B) [504.30(A)(1)](https://2023.antflix.net#504.30(A)(1)) | https://2023.antflix.net#504.30(A)(1) |
Chaptewr 5 Special Occupancies | 504.30(A)(2) | Conductors of intrinsically safe circuits shall be secured so that any conductor that might come loose from a terminal is unlikely to come into contact with another terminal. The conductors shall be separated from conductors of nonintrinsically safe circuits by one of the following methods: Separation by at least 50 mm (2 in.) from conductors of any nonintrinsically safe circuits, and securedSeparation from conductors of nonintrinsically safe circuits by use of a grounded metal partition 0.91 mm (0.0359 in.) or thicker or approved restricted access wiring ducts separated from other wiring ducts by a minimum of 19 mm (3/4 in.)Separation from conductors of nonintrinsically safe circuits by use of rigid insulating partition 0.91 mm (0.0359 in,) or thicker that extends to within 1.5 mm (0.0625 in.) of the enclosure wallsUse of separate wiring compartments for intrinsically safe and nonintrinsically safe terminalsEither all intrinsically safe circuit conductors or all nonintrinsically safe circuit conductors are installed in grounded metal-sheathed or metal-clad cables, where the sheathing or cladding is capable of carrying fault current to ground [504.30(A)(2)](https://2023.antflix.net#504.30(A)(2)) | https://2023.antflix.net#504.30(A)(2) |
Chaptewr 5 Special Occupancies | 504.30(A)(3) | Conductors and cables of intrinsically safe circuits run in other than raceway or cable tray systems shall be separated by at least 50 mm (2 in.) and secured from conductors and cables of any nonintrinsically safe circuits unless one of the following applies: All of the intrinsically safe circuit conductors are in Type MI or MC cables.All of the nonintrinsically safe circuit conductors are in raceways or Type MI or Type MC cables where the sheathing or cladding is capable of carrying fault current to ground. [504.30(A)(3)](https://2023.antflix.net#504.30(A)(3)) | https://2023.antflix.net#504.30(A)(3) |
Chaptewr 5 Special Occupancies | 504.30(B) | The clearance between two terminals for connection of field wiring of different intrinsically safe circuits shall be at least 6 mm (0.25 in.), unless this clearance is permitted to be reduced by the control drawing. Different intrinsically safe circuits shall be separated from each other by one of the following means: The conductors of each circuit are within a grounded metal shield.The conductors of each circuit have insulation with a minimum thickness of 0.25 mm (0.01 in.).Exception: Unless otherwise identified. [504.30(B)](https://2023.antflix.net#504.30(B)) | https://2023.antflix.net#504.30(B) |
Chaptewr 5 Special Occupancies | 504.30(C) | The clearance between the uninsulated parts of field wiring conductors connected to terminals and grounded metal or other conducting parts shall be at least 3 mm (0.125 in.). [504.30(C)](https://2023.antflix.net#504.30(C)) | https://2023.antflix.net#504.30(C) |
Chaptewr 5 Special Occupancies | 504.50(A) | Intrinsically safe apparatus, enclosures, and raceways, if of metal, shall be connected to the equipment grounding conductor. Informational Note: See ANSI/ISA RP 12.06.01, Recommended Practice for Wiring Methods for Hazardous (Classified) Locations Instrumentation - Part 1: Intrinsic Safety. In addition to an equipment grounding conductor connection, a connection to a grounding electrode might be needed for some associated apparatus, such as zener diode barriers, if specified in the control drawing. [504.50(A)](https://2023.antflix.net#504.50(A)) | https://2023.antflix.net#504.50(A) |
Chaptewr 5 Special Occupancies | 504.50(B) | Associated apparatus and cable shields shall be grounded in accordance with the required control drawing. See 504.10(A). Informational Note: See ANSI/ISA RP 12.06.01, Recommended Practice for Wiring Methods for Hazardous (Classified) Locations Instrumentation - Part 1: Intrinsic Safety. In addition to an equipment grounding conductor connection, a connection to a grounding electrode might be needed for some associated apparatus, such as zener diode barriers, if specified in the control drawing. [504.50(B)](https://2023.antflix.net#504.50(B)) | https://2023.antflix.net#504.50(B) |
Chaptewr 5 Special Occupancies | 504.50(C) | Where connection to a grounding electrode is required, the grounding electrode shall be as specified in 250.52(A)(1), (A)(2), (A)(3), and (A)(4) and shall comply with 250.30(A)(4). Sections 250.52(A)(5), (A)(7), and (A)(8) shall not be used if any of the electrodes specified in 250.52(A)(1), (A)(2), (A)(3), or (A)(4) are present. [504.50(C)](https://2023.antflix.net#504.50(C)) | https://2023.antflix.net#504.50(C) |
Chaptewr 5 Special Occupancies | 504.60(A) | Intrinsically safe apparatus, if of metal, shall be bonded in the hazardous (classified) location in accordance with 501.30(B), 502.30(B), 503.30(B), 505.30(B), or 506.30(B), as applicable. [504.60(A)](https://2023.antflix.net#504.60(A)) | https://2023.antflix.net#504.60(A) |
Chaptewr 5 Special Occupancies | 504.60(B) | Where metal raceways are used for intrinsically safe system wiring, bonding at all ends of the race-wav, regardless of the location, shall be in accordance with 501.30(B), 502.30(B), 503.30(B), 505.30(B), or 506.30(B), as applicable. [504.60(B)](https://2023.antflix.net#504.60(B)) | https://2023.antflix.net#504.60(B) |
Chaptewr 5 Special Occupancies | 504.70 | Conduits and cables that are required to be sealed by 501.15, 502.15, 505.16, and 506.16 shall be sealed to minimize the passage of gases, vapors, or dusts. Such seals shall not be required to be explosionproof or flameproof but shall be identified for the purpose of minimizing passage of gases, vapors, or dusts under normal operating conditions and shall be accessible. Exception: Seals shall not be required for enclosures that contain only intrinsically safe apparatus, except as required by 501.17. [504.70](https://2023.antflix.net#504.70) | https://2023.antflix.net#504.70 |
Chaptewr 5 Special Occupancies | 504.80 | Labels required by this section shall be suitable for the environment where they are installed, with consideration given to exposure to chemicals and sunlight. [504.80](https://2023.antflix.net#504.80) | https://2023.antflix.net#504.80 |
Chaptewr 5 Special Occupancies | 504.80(A) | Intrinsically safe circuits shall be identified at terminal and junction locations in a manner that is intended to prevent unintentional interference with the circuits during testing and servicing. [504.80(A)](https://2023.antflix.net#504.80(A)) | https://2023.antflix.net#504.80(A) |
Chaptewr 5 Special Occupancies | 504.80(B) | Raceways, cable trays, and other wiring methods for intrinsically safe system wiring shall be identified with permanently affixed labels with the wording "Intrinsic Safety Wiring" or equivalent. The labels shall be located so as to be visible after installation and placed so that they may be readily traced through the entire length of the installation. Intrinsic safety circuit labels shall appear in every section of the wiring system that is separated by enclosures, walls, partitions, or floors. Spacing between labels shall not be more than 7.5 m (25 ft). Exception: Circuits run underground shall be permitted to be identified where they become accessible after emergence from the ground. Informational Note No. 1: Wiring methods permitted in unclassified locations may be used for intrinsically safe systems in hazardous (classified) locations. Without labels to identify the application of the wiring, enforcement authorities cannot determine that an installation is in compliance with this Code. Informational Note No. 2: In unclassified locations, identification is necessary to ensure that nonintrinsically safe wire will not be inadvertently added to existing raceways at a later date. [504.80(B)](https://2023.antflix.net#504.80(B)) | https://2023.antflix.net#504.80(B) |
Chaptewr 5 Special Occupancies | 504.80(C) | Color coding shall be permitted to identify intrinsically safe conductors where they are colored light blue and where no other conductors colored light blue are used. Likewise, color coding shall be permitted to identify raceways, cable trays, and junction boxes where they are colored light blue and contain only intrinsically safe wiring. [504.80(C)](https://2023.antflix.net#504.80(C)) | https://2023.antflix.net#504.80(C) |
Chaptewr 5 Special Occupancies | 505.1(A) | This article covers the requirements for the zone classification system as an alternative to the division classification system covered in 500.1 for electrical and electronic equipment and wiring for all voltages where fire or explosion hazards might exist due to flammable gases, vapors, or liquids for the following: Zone 0 hazardous (classified) locationsZone 1 hazardous (classified) locationsZone 2 hazardous (classified) locationsInformational Note No. 1: The term "Class I" was originally included as a prefix to Zone 0, Zone 1, and Zone 2 locations and references as an identifier for flammable gases, vapors, or liquids to differentiate from Class II and Class III locations. Zone 0, Zone 1, and Zone 2 only apply to flammable gases, vapors, or liquids, so the "Class I" prefix is redundant and has been deleted. However, the marking of "Class I" is left as an optional marking within this Article.Informational Note No. 2: See NFPA 497-2021, Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas, for extracted text that is followed by a reference in brackets. Only editorial changes were made to the extracted text to make it consistent with this Code.Informational Note No. 3: See Article 100 for the definition of restricted industrial establishment [as applied to hazardous (classified) locations]. [505.1(A)](https://2023.antflix.net#505.1(A)) | https://2023.antflix.net#505.1(A) |
Chaptewr 5 Special Occupancies | 505.1(B) | This article does not cover electrical and electronic equipment and wiring in the following: Class I, Class II, or Class III, Division 1 or Division 2 hazardous (classified) locationsZone 20, Zone 21, or Zone 22 hazardous (classified) locationsLocations subject to the unique risk and explosion hazards associated with explosives, pyrotechnics, and blasting agentsLocations where pyrophoric materials are the only materials used or handledFeatures of equipment that involve nonelectrical potential sources of ignition (e.g., couplings, pumps, gearboxes, brakes, hydraulic and pneumatic motors, fans, engines, compressors)Informational Note No. 1: Common nonelectrical potential sources of ignition include hot surfaces and mechanically generated sparks.Informational Note No. 2: See ANSI/UL 80079-36, Explosive Atmospheres - Part 36: Non-Electrical Equipment for Explosive Atmospheres - Basic Method and Requirements, and ANSI/UL, 80079-37, Explosive Atmospheres - Part 3 7: Non-Electrical Equipment for Explosive Atmospheres - Non-Electrical Type of Protection Constructional Safety "c" Control of Ignition Source "b", Liquid Immersion "k", for additional information. [505.1(B)](https://2023.antflix.net#505.1(B)) | https://2023.antflix.net#505.1(B) |
Chaptewr 5 Special Occupancies | 505.4 | Areas designated as hazardous (classified) locations or as unclassified shall be documented on an area classification drawing and other associated documentation. This documentation shall be made available to the AHJ and those authorized to design, install, inspect, maintain, or operate electrical equipment at the location. Informational Note No. 1: See ANSI/API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2; ANSI/ISA 60079-10-1 (12.24.01), Explosive Atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres; and EI 15, Model Code of Safe Practice, Part 15: Area Classification for Installations Handling Flammable Fluids, for examples of area classification drawings. Informational Note No. 2: See 505.8(1)(2), (1)(3), or (1)(4) for information on where gas detection equipment is used as a means of protection. The documentation typically includes the type of detection equipment, its listing, the installation location(s), the alarm and shutdown criteria, and the calibration frequency. Informational Note No. 3: See NFPA 497, Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas; ANSI/API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2; ANSI/ISA 60079-10-1 (12.24.01), Explosive Atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres; and EI 15, Model Code of Safe Practice, Part 15: Area Classification for Installations Handling Flammable Fluids, for information on the classification of locations. Informational Note No. 4: See NFPA 77, Recommended Practice on Static Electricity, NFPA 780, Standard for the Installation of Lightning Protection Systems, and API RP 2003, Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents, for information on protection against static electricity and lightning hazards in hazardous (classified) locations. Informational Note No. 5: See NFPA 30, Flammable and Combustible Liquids Code, and ANSI/API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2, for information on ventilation. Informational Note No. 6: See ANSI/API RP 14FZ, Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Zone 0, Zone 1, and Zone 2 Locations, for information on electrical systems for hazardous (classified) locations on offshore oil and gas producing platforms, drilling rigs, and workover rigs. Informational Note No. 7: See UL 120101, Definitions and Information Pertaining to Electrical Apparatus in Hazardous Locations, and ANSI/UL 60079-0, Explosive Atmospheres - Part 0: Equipment - General Requirements, for further information on the general application of electrical equipment in hazardous (classified) locations. Informational Note No. 8: See ANSI/UL 121203, Portable/Personal Electronic Products Suitable for Use in Class I, Division 2, Class I, Zone 2, Class II, Division 2, Class III, Division 1, Class III, Division 2, Zone 21 and Zone 22 Hazardous (Classified) Locations, for information on whether portable or transportable equipment having self-contained power supplies, such as battery-operated equipment, could potentially become an ignition source in hazardous (classified) locations. Informational Note No. 9: See ANSI/UL 60079-28, Explosive Atmospheres - Part 28: Protection of Equipment and Transmission Systems Using Optical Radiation, for information concerning the installation of equipment utilizing optical emissions technology (such as laser equipment) that could potentially become an ignition source in hazardous (classified) locations. Informational Note No. 10: See IEC/IEEE 60079-30-2, Explosive Atmospheres - Part 30-2: Electrical Resistance Trace Heating - Application Guide for Design, Installation and Maintenance, for information on electrical resistance trace heating for hazardous (classified) locations. Informational Note No. 11: See IEEE 844.2/CSA C293.2, IEEE/CSA Standard for Skin Effect Trace Heating of Pipelines, Vessels, Equipment, and Structures - , for information on electric skin effect trace heating for hazardous (classified) locations. Informational Note No. 12: See IEEE 844.4/CSA C293.4, IEEE/CSA Standard for Impedance Heating of Pipelines and Equipment - Application Guide for Design, Installation, Testing, Commissioning and Maintenance, for information on electric impedance heating for hazardous (classified) locations. [505.4](https://2023.antflix.net#505.4) | https://2023.antflix.net#505.4 |
Chaptewr 5 Special Occupancies | 505.5(A)(1) | Locations shall be classified depending on the properties of the flammable gases, flammable liquid—produced vapors, combustible liquid—produced vapors, combustible dusts, or fibers/flyings that could be present and the likelihood that a flammable or combustible concentration or quantity is present. Each room, section, or area shall be considered individually in determining its classification. Informational Note No. 1: See 505.7 for restrictions on area classification. Informational Note No. 2: Through the exercise of ingenuity in the layout of electrical installations for hazardous (classified) locations, it is frequently possible to locate much of the equipment in a reduced level of classification or in an unclassified location to reduce the amount of special equipment required. [505.5(A)(1)](https://2023.antflix.net#505.5(A)(1)) | https://2023.antflix.net#505.5(A)(1) |
Chaptewr 5 Special Occupancies | 505.5(A)(2) | Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as "unclassified" locations. Informational Note: See ANSI/IIAR 2, Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems, for information on the classification and ventilation of areas involving closed-circuit ammonia refrigeration systems. [505.5(A)(2)](https://2023.antflix.net#505.5(A)(2)) | https://2023.antflix.net#505.5(A)(2) |
Chaptewr 5 Special Occupancies | 505.5(B) | Zone 0, 1, and 2 locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures. Zone 0, 1, and 2 locations shall include those specified in 505.5(B)(1), (B)(2), and (B)(3). [505.5(B)](https://2023.antflix.net#505.5(B)) | https://2023.antflix.net#505.5(B) |
Chaptewr 5 Special Occupancies | 505.5(B)(1) | A Zone 0 location is a location in which one of the following conditions exists: Ignitible concentrations of flammable gases or vapors are present continuouslyIgnitible concentrations of flammable gases or vapors are present for long periods of timeInformational Note No. 1: See ANSI/API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2, and ANSI/ISA 60079-10-1 (12.24.01), Explosive Atmospheres - Part 10-1: Classification of Areas - explosive gas atmospheres, for information for when flammable gases or vapors are present continuously or for long periods of time.Informational Note No. 2: This classification includes the following locations:Inside vented tanks or vessels that contain volatile flammable liquidsInside inadequately vented spraying or coating enclosures where volatile flammable solvents are usedBetween the inner and outer roof sections of a floating roof tank containing volatile flammable liquidsInside open vessels, tanks, and pits containing volatile flammable liquidsInterior of an exhaust duct used to vent ignitible concentrations of gases or vaporsInside inadequately ventilated enclosures that contain normally venting instruments using or analyzing flammable fluids and venting to the inside of the enclosures [505.5(B)(1)](https://2023.antflix.net#505.5(B)(1)) | https://2023.antflix.net#505.5(B)(1) |
Chaptewr 5 Special Occupancies | 505.5(B)(2) | A Zone 1 location is a location In which ignitible concentrations of flammable gases or vapors are likely to exist under normal operating conditions; orIn which ignitible concentrations of flammable gases or vapors may exist frequently because of repair or maintenance operations or because of leakage; orIn which equipment is operated or processes are carried on, of such a nature that equipment breakdown or faulty operations could result in the release of ignitible concentrations of flammable gases or vapors and also cause simultaneous failure of electrical equipment in a mode to cause the electrical equipment to become a source of ignition; orThat is adjacent to a Zone 0 location from which ignitible concentrations of vapors could be communicated, unless communication is prevented by adequate positive pressure ventilation from a source of clean air and effective safeguards against ventilation failure are provided.Informational Note No. 1: Normal operation is considered the situation when plant equipment is operating within its design parameters. Minor releases of flammable material may be part of normal operations. Minor releases include the releases from mechanical packings on pumps. Failures that involve repair or shutdown (such as the breakdown of pump seals and flange gaskets, and spillage caused by accidents) are not considered normal operation.Informational Note No. 2: This classification usually includes the following locations:Where volatile flammable liquids or liquefied flammable gases are transferred from one container to anotherAreas in the vicinity of spraying and painting operations where flammable solvents are usedAdequately ventilated drying rooms or compartments for evaporation of flammable solventsAdequately ventilated locations containing fat and oil extraction equipment using volatile flammable solventsPortions of cleaning and dyeing plants where volatile flammable liquids are usedAdequately ventilated gas generator rooms and other portions of gas manufacturing plants where flammable gas might escapeInadequately ventilated pump rooms for flammable gas or for volatile flammable liquidsInteriors of refrigerators and freezers in which volatile flammable materials are stored in the open, lightly stoppered, or in easily ruptured containersOther locations where ignitible concentrations of flammable vapors or gases are likely to occur in the course of normal operation but are not classified Zone 0 [505.5(B)(2)](https://2023.antflix.net#505.5(B)(2)) | https://2023.antflix.net#505.5(B)(2) |
Chaptewr 5 Special Occupancies | 505.5(B)(3) | A Zone 2 location is a location In which ignitible concentrations of flammable gases or vapors are not likely to occur in normal operation and, if they do occur, will exist only for a short period; orIn which volatile flammable liquids, flammable gases, or flammable vapors are handled, processed, or used but in which the liquids, gases, or vapors normally are confined within closed containers of closed systems from which they can escape, only as a result of accidental rupture or breakdown of the containers or system, or as a result of the abnormal operation of the equipment with which the liquids or gases are handled, processed, or used; orIn which ignitible concentrations of flammable gases or vapors normally are prevented by positive mechanical ventilation but which may become hazardous as a result of failure or abnormal operation of the ventilation equipment; orThat is adjacent to a Zone 1 location, from which ignitible concentrations of flammable gases or vapors could be communicated, unless such communication is prevented by adequate positive-pressure ventilation from a source of clean air and effective safeguards against ventilation failure are provided.Informational Note: The Zone 2 classification usually includes locations where volatile flammable liquids or flammable gases or vapors are used but which would become hazardous only in case of an accident or of some unusual operating condition. [505.5(B)(3)](https://2023.antflix.net#505.5(B)(3)) | https://2023.antflix.net#505.5(B)(3) |
Chaptewr 5 Special Occupancies | 505.6 | For purposes of testing, approval, and area classification, various air mixtures (not oxygen enriched) shall be grouped as required in 505.6(A), (B), and (C). Informational Note No. 1: See 90.2(D). This Code does not apply to installations underground in mines. Group I is intended for use in describing atmospheres that contain firedamp: a mixture of gases, composed mostly of methane, found underground, usually in mines. Informational Note No. 2: See ANSI/UL 60079-11, Explosive Atmospheres - Part 11: Equipment Protection by Intrinsic Safety "i". The gas and vapor subdivision is based on the maximum experimental safe gap (MESG), minimum igniting current (MIC), or both. Informational Note No. 3: See ISO/IEC 80079-20-1, Explosive atmospheres - Part 20-1: Material characteristics for gas and vapour classification - Test methods and data, for information on the test equipment for determining MIC in the classification of gases or vapors according to their maximum experimental safe gaps and minimum igniting currents. Informational Note No. 4: Group II is currently subdivided into Group IIA, Group IIB, and Group IIC. Prior marking requirements permitted some types of protection to be marked without a subdivision, showing only Group II. Informational Note No. 5: It is necessary that the meanings of the different equipment markings and Group II classifications be carefully observed to avoid confusion with Class I, Division 1 and Division 2, Groups A, B, C, and D. Zone 0, 1, and 2, groups shall be as follows: [505.6](https://2023.antflix.net#505.6) | https://2023.antflix.net#505.6 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.