46 CFR § 120.372 - Equipment and conductor grounding.
(a) All metallic enclosures and frames of electrical equipment must be permanently grounded to the hull on a metallic vessel. On a nonmetallic vessel, the enclosures and frames of electrical equipment must be bonded together to a common ground by a normally non-current carrying conductor. Metallic cases of instruments and secondary windings of instrument transformers must be grounded.
(b) On a nonmetallic vessel, where a ground plate is provided for radio equipment, it must be connected to the common ground.
(c) Equipment grounding conductors must be sized in accordance with Section 250-95 of the NEC (NFPA 70), or other standard specified by the Commandant.
(d) Each insulated grounding conductor of a cable must be identified by one of the following means.
(1) A green braid or green insulation;
(2) Stripping the insulation from the entire exposed length of the grounding conductor; or
(3) Marking the exposed insulation of the grounding conductor with green tape or green adhesive labels.
(e) Cable armor must not be used to ground electrical equipment of systems.