Fishing Docks, De-Icing Equipment and More

By Jim Dollard | Sep 11, 2023
Does all outdoor electrical distribution equipment at a commercial fishing dock require an equipotential plane?

Commercial fishing docks

Does all outdoor electrical distribution equipment at a commercial fishing dock require an equipotential plane? The installation is a 200A, 480V fused disconnect for two future industrial control panels for hoists. We questioned the need for it, never saw this before, and the engineer told us it is a Code thing. Is that true?

A commercial fishing dock is a special occupancy, and the requirements of Article 555 contain modifications and supplemental requirements for marinas, boatyards, floating buildings and commercial and noncommercial docking facilities. Section 555.14 contains requirements for equipotential planes. Equipotential planes are required in this installation only for service equipment or disconnecting means that control equipment in or on water, and only under either or both of the following conditions: (1) where the system voltage exceeds 250V to ground, and (2) where the equipment is located within 10 feet of the body of water. 

While your question does not include the distance from water, a 480V fused disconnect (controlling equipment in or on water) triggers this requirement. Where an equipotential plane is required, all metallic enclosures and controls likely to become energized and accessible to personnel must be bonded. The equipotential plane must completely cover the area around the equipment from the area directly below it and outward not less than 3 feet in all directions where a person could possibly stand and come in contact with the equipment.

GFCIs for gas-fired pool heater

Does a 120V hard-wired source to a gas heater for a swimming pool require GFCI protection? One inspector said no, but the guy that came out for the final said it is required.

Yes, GFCI protection is required. See Section 680.28, which requires any circuit supplying gas-fired swimming pool or spa water heaters that operate above the low-voltage contact limit (120V is above the low-voltage contact limit) be provided with GFCI protection. 

GFP for de-icing equipment

De-icing assemblies are shown on all roof edges on a new project. The shop drawings note ground-fault protection. Is this just a GFCI?

Fixed outdoor electric de-icing equipment is specifically addressed in Article 426. See Section 426.28, which requires ground-fault protection for all fixed outdoor electric de-icing and snow-melting equipment. This requirement mandates that the installer provide a ground-fault trip level as specified by the manufacturer. Note that the requirement is not for GFCI protection; it is simply ground-fault protection, which will likely be specified at a leakage current above that in a Class A GFCI. The specified setting by the manufacturer of the de-icing equipment for the ground-fault protection could be at 30 milliamps (mA), which is well above the 4- to 6-mA threshold for a Class A GFCI device.

Panelboard relocation

Due to insurance company demands, we are replacing 150 panelboards with older type molded-case circuit breakers with a history of failure in an apartment complex. The job is complicated by the fact that the panelboards are located in closets. Most replacements can be made by simply removing and replacing the panelboard to face into a hallway. However, some need to be moved a few feet with branch circuits spliced in the old can. Do we need AFCI circuit breakers for all of these?

No, see the applicable requirement in Section 210.12(E), which addresses extensions, modifications or replacements of branch circuit wiring. Where branch circuits are extended, the general rule requires AFCI protection of the entire branch circuit (circuit breaker type) or a listed outlet branch-­circuit-type AFCI located at the first receptacle outlet of the existing branch circuit. 

However, the exception to this rule applies to your installation. As long as the extension of the existing branch circuit conductors is not more than 6 feet and does not include any additional outlets or devices, other than splicing devices, AFCI protection is not required. The 6-foot measurement does not include the conductors inside the cabinet in which the panelboard is located, or the junction box (in this case, the original cabinet) in which they originate.

About The Author

DOLLARD is retired safety coordinator for IBEW Local 98 in Philadelphia. He is a past member of the NEC Correlating Committee, CMP-10, CMP-13, CMP-15, NFPA 90A/B and NFPA 855. Jim continues to serve on NFPA 70E and as a UL Electrical Council member. Reach him at [email protected].






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