46 CFR 169.667 - Switchboards.
(a) Each switchboard must be in as dry a location as practicable, accessible, protected from inadvertent entry, and adequately ventilated. All uninsulated current carrying parts must be mounted on nonabsorbent, noncombustible, high dielectric insulating material.
(b) Each switchboard must be -
(1) Totally enclosed; and
(2) Of the dead front type.
(c) Each ungrounded conductor of a circuit must have at the point of attachment to the power source either -
(1) A Circuit breaker; or
(2) A switch and fuse.
(d) Each switch other than one mounted on a switchboard must be of the enclosed type.