Ground-fault protection requirements for marinas, boatyards and docking facilities are being revised for the 2020 National Electrical Code.
The GFP requirements were divided into three parts to provide clarity, according to the International Association of Electrical Inspectors.
Section 555.35(A)(1) addresses shore power receptacles with individual GFPE not to exceed 30 milliamperes. Section 555.35(A)(2) addresses 15- and 20-ampere receptacles for other than shore power with Class A ground fault circuit interrupter protection (4 to 6 mA) being provided in accordance with NEC 210.8. Section 555.35(A)(3) addresses feeder and branch-circuit conductors that are installed on docking facilities to be provided with GFPE set to open at currents not exceeding 100 mA with coordination downstream GFPE permitted at the feeder overcurrent protective device.
An exception was added that exempts transformer secondary conductors of a separately derived system (exceeding 10 feet) installed in a raceway from this GFCE protection because it would be difficult to provide ground-fault protection on the conductors from the transformer to the first panel board where the transformer is located at a marina.
According to the IAEI, 50 percent of electric shock drowning incidents could have been prevented by the 30 mA protection at shore power receptacles. Informational notes will be added to address concerns regarding vessel testing to alleviate potential current leakage that contributes to ESD because test data has shown that much of the stray current in water around marinas comes from boats.
The NEC doesn’t have jurisdiction over boats in a marina. However, it can require current leakage measurement devices be in place at any facility where more than three receptacles supply shore power.