Article 513

Aircraft Hangars

1. Scope. This article shall apply to buildings or structures in any part of which aircraft containing Class I (flammable) liquids or Class II (combustible) liquids whose temperatures are above their flash points are housed or stored and in which aircraft might undergo service, repairs, or alterations. It shall not apply to locations used exclusively for aircraft that have never contained fuel or unfueled aircraft.Informational Note No. 1: For definitions of aircraft hangar and unfueled aircraft, see NFPA 409-2011, Standard on Aircraft Hang‐ ars.Informational Note No. 2: For further information on fuel classi‐ fication see NFPA 30 -2015, Flammable and Combustible Liquids Code.
2. Definitions. For the purpose of this article, the follow‐ ing definitions shall apply.Aircraft Painting Hangar. An aircraft hangar constructed for the express purpose of spray/coating/dipping applications and provided with dedicated ventilation supply and exhaust.•
3. Classification of Locations.
   1. Below Floor Level. Any pit or depression below the level of the hangar floor shall be classified as a Class I, Division 1 or Zone 1 location that shall extend up to said floor level.
   2. Areas Not Cut Off or Ventilated. The entire area of the hangar, including any adjacent and communicating areas not suitably cut off from the hangar, shall be classified as a Class I, Division 2 or Zone 2 location up to a level 450 mm (18 in.) above the floor.
   3. Vicinity of Aircraft.
      1. Aircraft Maintenance and Storage Hangars. The area within 1.5 m (5 ft) horizontally from aircraft power plants or aircraft fuel tanks shall be classified as a Class I, Division 2 or Zone 2 location that shall extend upward from the floor to a level 1.5 m (5 ft) above the upper surface of wings and of engine enclosures.
      2. Aircraft Painting Hangars. The area within 3 m (10 ft) horizontally from aircraft surfaces from the floor to 3 m (10 ft) above the aircraft shall be classified as Class I, Division 1 orClass I, Zone 1. The area horizontally from aircraft surfaces between 3.0 m (10 ft) and 9.0 m (30 ft) from the floor to 9.0 m (30 ft) above the aircraft surface shall be classified as Class I, Division 2 or Class I, Zone 2.Informational Note: See NFPA 33-2015, Standard for Spray Appli‐ cation Using Flammable or Combustible Materials, for information on ventilation and grounding for static protection in spray painting areas.
   4. Areas Suitably Cut Off and Ventilated. Adjacent areas in which flammable liquids or vapors are not likely to be released, such as stock rooms, electrical control rooms, and other similar locations, shall be unclassified where adequately ventilated and where effectively cut off from the hangar itself by walls or parti‐ tions.
4. Wiring and Equipment in Class I Locations.

1. General. All wiring and equipment that is or may be installed or operated within any of the Class I locations defined in 513.3 shall comply with the applicable provisions of Article 501 or Article 505 for the division or zone in which they are used.Attachment plugs and receptacles in Class I locations shall be identified for Class I locations or shall be designed such that they cannot be energized while the connections are being made or broken.
2. Stanchions, Rostrums, and Docks. Electrical wiring, outlets, and equipment (including lamps) on or attached to stanchions, rostrums, or docks that are located or likely to be located in a Class I location, as defined in 513.3(C), shall comply with the applicable provisions of Article 501 or Arti‐ cle 505 for the division or zone in which they are used.

1. Wiring and Equipment Not Installed in Class I Loca‐ tions.
   1. Fixed Wiring. All fixed wiring in a hangar but not instal‐ led in a Class I location as classified in 513.3 shall be installed in metal raceways or shall be Type MI, TC, or MC cable.Exception: Wiring in unclassified locations, as described in 513.3(D), shall be permitted to be any suitable type wiring method recognized in Chapter 3.
   2. Pendants. For pendants, flexible cord suitable for the type of service and identified for hard usage or extra-hard usage shall be used. Each such cord shall include a separate equipment grounding conductor.
   3. Arcing Equipment. In locations above those described in 513.3, equipment that is less than 3.0 m (10 ft) above wings and engine enclosures of aircraft and that may produce arcs, sparks, or particles of hot metal, such as lamps and lamphold‐ ers for fixed lighting, cutouts, switches, receptacles, charging panels, generators, motors, or other equipment having make- and-break or sliding contacts, shall be of the totally enclosed type or constructed so as to prevent the escape of sparks or hot metal particles.Exception: Equipment in areas described in 513.3(D) shall be permitted to be of the general-purpose type.
   4. Lampholders. Lampholders of metal-shell, fiber-lined types shall not be used for fixed incandescent lighting.ARTICLE 513 — AIRCRAFT HANGARS 513.10
   5. Stanchions, Rostrums, or Docks. Where stanchions, rostrums, or docks are not located or likely to be located in a Class I location, as defined in 513.3(C), wiring and equipment shall comply with 513.7, except that such wiring and equip‐ ment not more than 457 mm (18 in.) above the floor in any position shall comply with 513.4(B). Receptacles and attach‐ ment plugs shall be of a locking type that will not readily disconnect.
   6. Mobile Stanchions. Mobile stanchions with electrical equipment complying with 513.7(E) shall carry at least one permanently affixed warning sign with the following words or equivalent:
   WARNINGKEEP 5 FT CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREASorWARNINGKEEP 1.5 METERS CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREAS
2. Underground Wiring.
   1. Wiring and Equipment Embedded, Under Slab, or Under‐ ground. All wiring installed in or under the hangar floor shall comply with the requirements for Class I, Division 1 locations. Where such wiring is located in vaults, pits, or ducts, adequate drainage shall be provided.
   2. Uninterrupted Raceways, Embedded, Under Slab, or Underground. Uninterrupted raceways that are embedded in a hangar floor or buried beneath the hangar floor shall be considered to be within the Class I location above the floor, regardless of the point at which the raceway descends below or rises above the floor.
3. Sealing. Seals shall be provided in accordance with

501.15 or 505.16, as applicable. Sealing requirements specified shall apply to horizontal as well as to vertical boundaries of the defined Class I locations.

513.10 Special Equipment.

1. Aircraft Electrical Systems.
   1. De-energizing Aircraft Electrical Systems. Aircraft electri‐ cal systems shall be de-energized when the aircraft is stored in a hangar and, whenever possible, while the aircraft is undergoing maintenance.
   2. Aircraft Batteries. Aircraft batteries shall not be charged where installed in an aircraft located inside or partially inside a hangar.
2. Aircraft Battery Charging and Equipment. Battery charg‐ ers and their control equipment shall not be located or oper‐ ated within any of the Class I locations defined in 513.3 and shall preferably be located in a separate building or in an area such as defined in 513.3(D). Mobile chargers shall carry at least one permanently affixed warning sign with the following words or equivalent:WARNINGKEEP 5 FT CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREAS
   WARNINGKEEP 1.5 METERS CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREASTables, racks, trays, and wiring shall not be located within a Class I location and, in addition, shall comply with Article 480.
3. External Power Sources for Energizing Aircraft.
   1. Not Less Than 450 mm (18 in.) Above Floor. Aircraft energizers shall be designed and mounted such that all electri‐ cal equipment and fixed wiring will be at least 450 mm (18 in.) above floor level and shall not be operated in a Class I location as defined in 513.3(C).
   2. Marking for Mobile Units. Mobile energizers shall carry at least one permanently affixed warning sign with the following words or equivalent:WARNINGKEEP 5 FT CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREASorWARNINGKEEP 1.5 METERS CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREAS
   3. Cords. Flexible cords for aircraft energizers and ground support equipment shall be identified for the type of service and extra-hard usage and shall include an equipment ground‐ ing conductor.
4. Mobile Servicing Equipment with Electrical Components.
   1. General. Mobile servicing equipment (such as vacuum cleaners, air compressors, air movers) having electrical wiring and equipment not suitable for Class I, Division 2 or Zone 2 locations shall be so designed and mounted that all such fixed wiring and equipment will be at least 450 mm (18 in.) above the floor. Such mobile equipment shall not be operated within the Class I location defined in 513.3(C) and shall carry at least one permanently affixed warning sign with the following words or equivalent:WARNINGKEEP 5 FT CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREASorWARNINGKEEP 1.5 METERS CLEAR OF AIRCRAFT ENGINES AND FUEL TANK AREAS
   2. Cords and Connectors. Flexible cords for mobile equip‐ ment shall be suitable for the type of service and identified for extra-hard usage and shall include an equipment grounding conductor. Attachment plugs and receptacles shall be identi‐ fied for the location in which they are installed and shall provide for connection of the equipment grounding conduc‐ tor.
   3. Restricted Use. Equipment that is not identified as suita‐ ble for Class I, Division 2 locations shall not be operated in locations where maintenance operations likely to release flam‐ mable liquids or vapors are in progress.or
5. Portable Equipment.
   1. Portable Lighting Equipment. Portable lighting equip‐ ment that is used within a hangar shall be identified for the location in which they are used. For portable luminaires, flexi‐ ble cord suitable for the type of service and identified for extra- hard usage shall be used. Each such cord shall include a separate equipment grounding conductor.
   2. Portable Utilization Equipment. Portable utilization equipment that is or may be used within a hangar shall be of a type suitable for use in Class I, Division 2 or Zone 2 locations. For portable utilization equipment, flexible cord suitable for the type of service and approved for extra-hard usage shall be used. Each such cord shall include a separate equipment grounding conductor.

513.12 Ground-Fault Circuit-Interrupter Protection for Personnel. All 125-volt, 50/60-Hz, single-phase, 15– and 20-ampere receptacles installed in areas where electrical diag‐ nostic equipment, electrical hand tools, or portable lighting equipment are to be used shall have ground-fault circuit- interrupter protection for personnel.

513.16 Grounding and Bonding Requirements.

1. General Grounding Requirements. All metal raceways, the metal armor or metallic sheath on cables, and all non– current-carrying metal parts of fixed or portable electrical equipment, regardless of voltage, shall be grounded. Ground‐ ing in Class I locations shall comply with 501.30 for Class I, Division 1 and 2 locations and 505.25 for Class I, Zone 0, 1, and 2 locations.
2. Supplying Circuits with Grounded and Grounding Conduc‐ tors in Class I Locations.
   1. Circuits Supplying Portable Equipment or Pendants. Where a circuit supplies portables or pendants and includes a grounded conductor as provided in Article 200, receptacles, attachment plugs, connectors, and similar devices shall be of the grounding type, and the grounded conductor of the flexi‐ ble cord shall be connected to the screw shell of any lamp‐ holder or to the grounded terminal of any utilization equipment supplied.
   2. Approved Means. Approved means shall be provided for maintaining continuity of the grounding conductor between the fixed wiring system and the non–current-carrying metal portions of pendant luminaires, portable luminaires, and port‐ able utilization equipment.

dispensing facilities located inside buildings, and fleet vehicle motor fuel dispensing facilities.

Informational Note: For further information regarding safe‐ guards for motor fuel dispensing facilities, see NFPA 30A-2015, Code for Motor Fuel Dispensing Facilities and Repair Garages.

1. Definition.Motor Fuel Dispensing Facility. That portion of a property where motor fuels are stored and dispensed from fixed equip‐ ment into the fuel tanks of motor vehicles or marine craft or into approved containers, including all equipment used in connection therewith. [30A:3.3.11]Informational Note: Refer to Articles 510 and 511 with respect to electrical wiring and equipment for other areas used as lubri‐ toriums, service rooms, repair rooms, offices, salesrooms, compressor rooms, and similar locations.
2. Classification of Locations. [See Figure 514.3.]
   1. Unclassified Locations. Where the authority having juris‐ diction can satisfactorily determine that flammable liquids having a flash point below 38°C (100°F), such as gasoline, will not be handled, such location shall not be required to be classi‐ fied.
   2. Classified Locations. [See Figure 514.3(B).]0.5 m (18 in.)0.5 m(18 in.)6 m (20 ft)Below grade sump
      1. Class I Locations. Table 514.3(B)(1) shall be applied where Class I liquids are stored, handled, or dispensed and shall be used to delineate and classify motor fuel dispensing facilities and commercial garages as defined in Article 511. Table 515.3 shall be used for the purpose of delineating and