Ground-fault protection at docks and marinas
Docks, including private residential docks, need ground-fault protection: 100 mA or less on dock feeders, 30 mA or less on each shore-power receptacle, and GFCI on other outlets and boat hoist outlets within set voltage and amp limits.
What the code requires
Section 555.35 applies to docking facilities other than floating buildings, and Article 555 covers noncommercial residential docks as well as marinas. Feeders installed on docks need listed ground-fault protection of equipment (GFPE) set at 100 mA or less. Coordination with downstream GFPE is permitted.
Shore-power receptacles (555.33(A)) need listed GFPE rated 30 mA or less. Other outlets need GFCI protection where they are 150 volts or less to ground and 60 A or less single-phase, or 100 A or less three-phase. Outlets of 240 volts or less that supply a boat hoist need GFCI protection.
Where a facility has more than 3 shore-power receptacles, a listed leakage-current measurement device for marina use must be available and used; the listing requirement takes effect January 1, 2026. Shore-power equipment with a built-in leakage indicator and alarm does not need a separate tester.
On the job
- Private docks at homes are covered, not just commercial marinas.
- Replacement shore-power receptacles need GFPE too (406.4(D)(8)).
- The 2023 edition also added an emergency shutoff requirement at marina power outlets (555.36(C)).
Exceptions that matter
- Transformer secondary conductors of a separately derived system, run 10 ft (3 m) or less in raceway, are exempt from the feeder ground-fault protection requirement.
- Low-voltage circuits that meet 680.23(A)(2) are exempt from GFCI protection.
What changed in 2023
The 2023 edition limited the 100 mA GFPE rule to dock feeders, widened GFCI from 125-V, 15- and 20-A receptacles to outlets up to 150 V to ground (60 A single-phase, 100 A three-phase), moved the boat hoist GFCI rule here from 555.9, and added a listing requirement for the leakage-current device. TIA 23-6 (effective Sept 1, 2022, folded in before printing) deleted a planned rule for 100 mA GFPE at the source supplying docks, so confirm with your building department.
Related sections
- NEC 555.33
- NEC 555.36(C)
- NEC 555.30
- NEC 406.4(D)(8)
- NEC 680.23(A)(2)
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