Stumped by the Code? NEC Requirements for Protection of Flexible Cords at Carnivals, Circuses, or Fairs
Courtesy of www.MikeHolt.com
All questions and answers are based on the 2020 NEC.
Q. What is the Code definition of equipotential plane as applied to agricultural buildings?
A. Equipotential Plane, (as applied to agricultural buildings), is defined as an area where conductive elements are embedded in or placed under concrete and bonded to all metal structures and nonelectrical equipment that could become energized and connected to the electrical system to minimize voltage differences within the plane [Sec. 547.2], as shown in the Figure.
Q. What does the NEC require for protection of flexible cords or cables used for wiring methods at carnivals, circuses, or fairs?
A. Flexible cords or flexible cables accessible to the public must be arranged to minimize the tripping hazard, and they can be covered with nonconductive matting secured to the walkway surface or protected with another approved cable protection method, provided that the matting or other protection method does not constitute a greater tripping hazard than the uncovered cables. Burying cables is permitted, and the burial depth requirements of Sec. 300.5 do not apply [Sec. 525.20(G)].
Q. What is the NEC requirement when installing a separate equipment grounding conductor underground at an agricultural building?
A. Where the equipment grounding conductor is not part of a listed cable assembly, it must be insulated when installed underground [Sec. 547.5(F)].
Q. What are the specific NEC requirements for GFCI protection at agricultural buildings?
A. Ground-fault circuit-interrupter (GFCI) protection must be provided as required in Sec. 210.8(B), but GFCI protection is not required for receptacles rated 30A or more installed within the following areas:
(1) In areas having an equipotential plane in accordance with Sec. 547.10(A).
(2) Outdoors.
(3) In damp or wet locations.
(4) In dirt confinement areas for livestock.
Q. What does the NEC require as electrical datum plane distances for floating piers and areas subject to tidal fluctuations?
A. The electrical datum plane for floating piers and boat landing stages must be a horizontal plane 30 in. above the water level at the floating pier and a minimum of 12 in. above the level of the deck [Sec. 555.3(A)].
Areas subject to tidal fluctuations – In land areas subject to tidal fluctuation, the electrical datum plane must be a horizontal plane that is 2 ft above the highest tide level for the area occurring under normal circumstances, based on the highest high tide [Sec. 555.3(B)].
Areas not subject to tidal fluctuations – In land areas not subject to tidal fluctuation, the electrical datum plane must be a horizontal plane that is 2 ft above the highest water level for the area occurring under normal circumstances [Sec. 555.3(C)].
Q. What is the NEC rule regarding protection of lamps that are part of temporary installations?
A. Lamps (bulbs) must be protected from accidental contact by a suitable luminaire or lampholder with a guard [Sec. 590.4(F)].
These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.
