---
kind: "section"
citation: "46 C.F.R. § 129.375"
title: "46"
number: "129.375"
heading: "System grounding."
url: "https://uscodex.org/cfr/46/129.375"
---

# §129.375. System grounding.

- (a) If a grounded distribution system is provided, there must be only one connection to ground, regardless of the number of power sources. This connection must be at the main switchboard.
- (b) On each metallic vessel, a grounded distribution system must be grounded to the hull. On each nonmetallic vessel, the neutral of a grounded system must be connected to a common ground plate, except that no aluminum grounding conductors may be used.
- (c) On each nonmetallic vessel with a grounded distribution system, the common ground plate must have—
  - (1) Only one connection to the main switchboard; and
  - (2) **The connection to itself readily accessible for checking.**
- (d) On each nonmetallic vessel with a ground plate provided for radio equipment, the plate must be connected to the common ground plate.
- (e) Each insulated grounding-conductor of a cable must be identified by one of the following means:
  - (1) **Wrapping of the cable with green braid or green insulation.**
  - (2) **Stripping of the insulation from the entire exposed length of the grounding-conductor.**
  - (3) **Marking of the exposed insulation of the grounding-conductor with green tape or green adhesive labels.**
- (f) No vessel's hull may carry current as a conductor except for—
  - (1) An impressed-current cathodic-protection system; or
  - (2) **A battery system to start an engine.**
- (g) No cable armor may be used to ground electrical equipment or systems.
- (h) Each receptacle outlet and attachment plug, for a portable lamp, tool, or similar apparatus operating at 100 or more volts, must have a grounding-pole and a grounding-conductor in the portable cord.

## Notes

### Authority

Authority: 46 U.S.C. 3306; sec. 617, Pub. L. 111-281, 124 Stat. 2905; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 82-004 and CGD 86-074, 62 FR 49332, Sept. 19, 1997, unless otherwise noted.