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Author(s): Derek Vigstol. Published on September 1, 2017.

In Compliance | NEC

New provisions in the NEC to improve electrical safety around water


The weeks following Labor Day still count as deep summer for many parts of the country, and many of us search for ways to escape, relax, and enjoy the autumn heat. This often means heading to the lake or coast to spend time on the water. But is the water safe to go in?

Headlines of deaths from across the country continue to serve as sober warnings of the risk of electric shock drowning (ESD), where electrical current in the water immobilizes or kills people. ESD can occur anywhere electricity is located near the water. Docking facilities commonly supply shore power to boats or have electrical equipment installed directly on them. While it is true that the National Electrical Code® (NEC®) does not cover electrical systems and equipment installed within the boats themselves, it does cover all of the installation up to the boat.

The 2017 edition of the NEC saw certain revisions aimed at curbing this deadly phenomenon. Article 555, which covers marinas, boatyards, and docking facilities, has been expanded to include docking facilities associated with one-, two-, and multi-family dwelling units. These docks were specifically excluded in previous editions. This expansion brings all of the safety measures included in Article 555 into the residential world, where many of these incidents occur. Due to the corrosive nature of marine environments, many of these requirements are aimed at preserving the integrity of the electrical system, such as the requirement to use an insulated equipment grounding conductor.

Another major revision addressed the level of ground-fault protection required for the overcurrent protective device supplying the marina, boatyard, or docking facility. The maximum trip threshold for this ground-fault protection has been reduced from 100 mA to 30 mA based on data from a Fire Protection Research Foundation and American Boat & Yacht Council Foundation report. This level of ground-fault protection applies to any overcurrent protection device that supplies power to these facilities and is in addition to any ground-fault circuit interrupter that is required for specific outlets and receptacles. It is important to note that this GFCI protection required for receptacles and outlets by other parts of the NEC must have a trip setting in the 4–6 mA range.

New in Article 555 for 2017 is the addition of a warning sign that must be clearly visible from all approaches to a marina or boatyard facility. While this is not necessarily an electrical requirement, it is similar to the requirement to warn service personnel when an arc-flash hazard exists as required in Section 110.16. This signage must display the words “WARNING—POTENTIAL SHOCK HAZARD—ELECTRICAL CURRENTS MAY BE PRESENT IN THE WATER.” The intent is that those entering the area are warned of the potential danger of diving in. Other language can also be added to these signs, such as no-swimming policies.

Maintaining the integrity of the system is critical to improving safety for the people using them, and the NEC requires that any equipment installed must be able to withstand its environment. All manner of events can take place after the installation that can damage or deteriorate the equipment, however. Boats colliding with docks can damage wiring, wood can rot and lose its ability to properly support equipment, and water can find its way into places it doesn’t belong. Maintaining the system afterward is just as important as the initial installation requirements.

As the NEC evolves to address this issue, it is important to remember the end goal, which is the same as the NEC’s purpose—“the practical safeguarding of persons and property from the hazards arising from the use of electricity.” If we install, inspect, and maintain electrical equipment in marine facilities with the NEC’s purpose in mind, safety will improve, making tragic ESD headlines a thing of the past.

DEREK VIGSTOL is NFPA technical lead of Electrical Tech Services.