Article 511

1. Commercial Garages, Repair and StorageInformational Note: Text that is followed by a reference in brackets has been extracted from NFPA 30A-2015, Code for Motor Fuel Dispensing Facilities and Repair Garages. Only editorial changes were made to the extracted text to make it consistent with this Code.
   1. Scope. These occupancies shall include locations used for service and repair operations in connection with self- propelled vehicles (including, but not limited to, passenger automobiles, buses, trucks, and tractors) in which volatile flam‐ mable liquids or flammable gases are used for fuel or power.
   2. Definitions.Major Repair Garage. A building or portions of a building where major repairs, such as engine overhauls, painting, body and fender work, and repairs that require draining of the motor vehicle fuel tank are performed on motor vehicles, including associated floor space used for offices, parking, or showrooms. [30A:3.3.12.1]Minor Repair Garage. A building or portions of a building used for lubrication, inspection, and minor automotive mainte‐ nance work, such as engine tune-ups, replacement of parts, fluid changes (e.g., oil, antifreeze, transmission fluid, brake fluid, air-conditioning refrigerants), brake system repairs, tire rotation, and similar routine maintenance work, including associated floor space used for offices, parking, or showrooms. [30A:3.3.12.2]
   3. Area Classification, General. Where Class I liquids or gaseous fuels are stored, handled, or transferred, electrical wiring and electrical utilization equipment shall be designed in accordance with the requirements for Class I, Division 1 or 2 hazardous (classified) locations as classified in accordance with500.5 and 500.6, and this article. A Class I location shall not extend beyond an unpierced wall, roof, or other solid partition that has no openings. [30A: 8.3.1, 8.3.3]
      1. Parking Garages. Parking garages used for parking or storage shall be permitted to be unclassified.Informational Note: For further information, see NFPA 88A -2015, Standard for Parking Structures, and NFPA 30A -2015, Code for Motor Fuel Dispensing Facilities and Repair Garages.
      2. Repair Garages, with Dispensing. Major and minor repair garages that dispense motor fuels into the fuel tanks of vehi‐ cles, including flammable liquids having a flash point below 38°C (100°F) such as gasoline, or gaseous fuels such as natural
2. Repair Garages, Major. Where vehicles using lighter-than- air gaseous fuels (such as hydrogen and natural gas) are repaired or stored, hazardous area classification guidance is found in Table 511.3(D).
   Informational Note: For additional information see NFPA30A-2015, Code for Motor Fuel Dispensing Facilities and Repair Garages, Table 8.3.2.•
3. Modifications to Classification.
   1. Specific Areas Adjacent to Classified Locations. Areas adjacent to classified locations in which flammable vapors are not likely to be released, such as stock rooms, switchboard rooms, and other similar locations, shall be unclassified where mechanically ventilated at a rate of four or more air changes per hour, or designed with positive air pressure, or where effec‐ tively cut off by walls or partitions.
   2. Alcohol-Based Windshield Washer Fluid. The area used for storage, handling, or dispensing into motor vehicles of alcohol-based windshield washer fluid in repair garages shall be unclassified unless otherwise classified by a provision of 511.3. [30A: 8.3.1, Exception]
4. Wiring and Equipment in Class I Locations.

1. Wiring Located in Class I Locations. Within Class I loca‐ tions as classified in 511.3, wiring shall conform to applicable provisions of Article 501.
2. Equipment Located in Class I Locations. Within Class I locations as defined in 511.3, equipment shall conform to applicable provisions of Article 501.
   1. Fuel-Dispensing Units. Where fuel-dispensing units (other than liquid petroleum gas, which is prohibited) are located within buildings, the requirements of Article 514 shall govern.Where mechanical ventilation is provided in the dispensing area, the control shall be interlocked so that the dispenser cannot operate without ventilation, as prescribed in 500.5(B)(2).
   2. Portable Lighting Equipment. Portable lighting equip‐ ment shall be equipped with handle, lampholder, hook, and substantial guard attached to the lampholder or handle. All exterior surfaces that might come in contact with battery termi‐ nals, wiring terminals, or other objects shall be of nonconduct‐ ing material or shall be effectively protected with insulation. Lampholders shall be of an unswitched type and shall not provide means for plug-in of attachment plugs. The outer shell shall be of molded composition or other suitable material. Unless the lamp and its cord are supported or arranged in such

511.7 ARTICLE 511 — COMMERCIAL GARAGES, REPAIR AND STORAGE

N Table 511.3(C) Extent of Classified Locations for Major and Minor Repair Garages with Heavier-Than-Air Fuel

Class I

	Location	Division (Group D)	Zone (Group IIA)	Extent of Classified Location
Repair garage, major		1	1	Entire space within any pit, belowgrade work area,

(where Class I liquids or gaseous fuels are transferred or dispensed*)

or subfloor work area that is not ventilated

2 2 Entire space within any pit, belowgrade work area, or subfloor work area that is provided with ventilation of at least 0.3 m3/min/m2

(1 ft3/min/ft2) of floor area, with suction taken from a point within 300 mm (12 in.) of floor level

2 2 Up to 450 mm (18 in.) above floor level of the room, except as noted below, for entire floor area

Unclassified Unclassified Up to 450 mm (18 in.) above floor level of the

room where room is provided with ventilation of at least 0.3 m3/min/m2 (1 ft3/min/ft2) of floor area, with suction taken from a point within

300 mm (12 in.) of floor level

2 2 Within 0.9 m (3 ft) of any fill or dispensing point, extending in all directions

Specific areas adjacent to classified locations Unclassified Unclassified Areas adjacent to classified locations where

flammable vapors are not likely to be released, such as stock rooms, switchboard rooms, and other similar locations, where mechanically ventilated at a rate of four or more air changes per hour or designed with positive air pressure or where effectively cut off by walls or partitions

Repair garage, minor

(where Class I liquids or gaseous fuels are not transferred or dispensed*)

2 2 Entire space within any pit, belowgrade work area,

or subfloor work area that is not ventilated

2 2 Up to 450 mm (18 in.) above floor level, extending

0.9 m (3 ft) horizontally in all directions from opening to any pit, belowgrade work area, or subfloor work area that is not ventilated

Unclassified Unclassified Entire space within any pit, belowgrade work area,

or subfloor work area that is provided with ventilation of at least 0.3 m3/min/m2

(1 ft3/min/ft2) of floor area, with suction taken from a point within 300 mm (12 in.) of floor level

Specific areas adjacent to classified locations	Unclassified	Unclassified	Areas adjacent to classified locations where
	flammable vapors are not likely to be released,
such as stock rooms, switchboard rooms, and
other similar locations, where mechanically
ventilated at a rate of four or more air changes
per hour or designed with positive air pressure,
or where effectively cut off by walls or partitions

*Includes draining of Class I liquids from vehicles.

a manner that they cannot be used in the locations classified in 511.3, they shall be of a type identified for Class I, Division 1 locations.

1. Wiring and Equipment Installed Above Class I Loca‐ tions.
   1. Wiring in Spaces Above Class I Locations.
      1. Fixed Wiring Above Class I Locations. All fixed wiring above Class I locations shall be in metal raceways, rigid nonme‐ tallic conduit, electrical nonmetallic tubing, flexible metal conduit, liquidtight flexible metal conduit, or liquidtight flexi‐ble nonmetallic conduit, or shall be Type MC, AC, MI, manu‐ factured wiring systems, or PLTC cable in accordance with Article 725, or Type TC cable or Type ITC cable in accordance with Article 727. Cellular metal floor raceways or cellular concrete floor raceways shall be permitted to be used only for supplying ceiling outlets or extensions to the area below the floor, but such raceways shall have no connections leading into or through any Class I location above the floor.
      2. Pendant. For pendants, flexible cord suitable for the type of service and listed for hard usage shall be used.
         N Table 511.3(D) Extent of Classified Locations for Major Repair Garages with Lighter-than-Air Fuel
         
         LocationClass IDivision2 Zone3
         Extent of Classified LocationRepair garage, major (where lighter-than-air gaseous fueled1 vehicles are repaired or stored)2 2 Within 450 mm (18 in.) of ceiling, except as noted belowUnclassified Unclassified Within 450 mm (18 in.) of ceilingwhere ventilation of at least0.3 m3/min/m2 (1 ft3/min/ft2) of floor area, with suction taken from a point within 450 mm (18 in.) of the highest point in the ceilingSpecific areas adjacent to classified locations Unclassified Unclassified Areas adjacent to classified locationswhere flammable vapors are not likely to be released, such as stock rooms, switchboard rooms, and other similar locations, where mechanically ventilated at a rate of four or more air changes per hour or designed with positive air pressure, or whereeffectively cut off by walls or partitions1Includes fuels such as hydrogen and natural gas, but not LPG.2For hydrogen (lighter than air) Group B, or natural gas Group D.3For hydrogen (lighter than air) Group IIC or IIB+H2, or natural gas Group IIA.
   2. Electrical Equipment Installed Above Class I Locations.
      1. Fixed Electrical Equipment. Electrical equipment in a fixed position shall be located above the level of any defined Class I location or shall be identified for the location.
         1. Arcing Equipment. Equipment that is less than 3.7 m (12 ft) above the floor level and that may produce arcs, sparks, or particles of hot metal, such as cutouts, switches, charging panels, generators, motors, or other equipment (excluding receptacles, lamps, and lampholders) 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.
         2. Fixed Lighting. Lamps and lampholders for fixed lighting that is located over lanes through which vehicles are commonly driven or that may otherwise be exposed to physical damage shall be located not less than 3.7 m (12 ft) above floor level, unless of the totally enclosed type or constructed so as to prevent escape of sparks or hot metal particles.
   N
2. Underground Wiring. Underground wiring shall be installed in threaded rigid metal conduit or intermediate metal conduit.Exception: Type PVC conduit, Type RTRC conduit, and Type HDPE conduit shall be permitted where buried under not less than 600 mm (2 ft) of cover. Where Type PVC conduit, Type RTRC conduit, or Type HDPE conduit is used, threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last 600 mm (2 ft) of the underground run to emergence or to the point of connection to the aboveground raceway, and an equipment grounding conductor shall be included to provide electrical continuity of the raceway system and for grounding of non–current-carrying metal parts.
3. Sealing. Seals complying with the requirements of501.15 and 501.15(B)(2) shall be provided and shall apply to horizontal as well as vertical boundaries of the defined Class I locations.
4. Special Equipment.

1. Battery Charging Equipment. Battery chargers and their control equipment, and batteries being charged, shall not be located within locations classified in 511.3.
2. Electric Vehicle Charging Equipment.
   1. General. All electrical equipment and wiring shall be installed in accordance with Article 625, except as noted in 511.10(B)(2) and (B)(3). Flexible cords shall be of a type iden‐ tified for extra-hard usage.
   2. Connector Location. No connector shall be located within a Class I location as defined in 511.3.
   3. Plug Connections to Vehicles. Where the cord is suspen‐ ded from overhead, it shall be arranged so that the lowest point of sag is at least 150 mm (6 in.) above the floor. Where an auto‐ matic arrangement is provided to pull both cord and plug beyond the range of physical damage, no additional connector shall be required in the cable or at the outlet.

511.12 Ground-Fault Circuit-Interrupter Protection for Personnel. All 125-volt, single-phase, 15- and 20-ampere recep‐ tacles installed in areas where electrical diagnostic equipment, electrical hand tools, or portable lighting equipment are to be used shall have ground-fault circuit-interrupter protection for personnel.

511.16 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.
2. Supplying Circuits with Grounded and Grounding Conduc‐ tors in Class I Locations. Grounding in Class I locations shall comply with 501.30.

511.16 ARTICLE 513 — AIRCRAFT HANGARS

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 equipment grounding conductor between the fixed wiring system and the non–current-carrying metal portions of pendant luminaires, portable luminaires, and portable utilization equipment.