46 CFR §111.05-23

1. (a)Be at the vessel's ship's service generator distribution switchboard for the normal power, normal lighting, and emergency lighting systems;
2. (b)Be at the propulsion switchboard for propulsion systems; and
3. (c)Be readily accessible.
4. (d)Be provided (at the distribution switchboard or at another location, such as a centralized monitoring position for the circuit affected) for each feeder circuit that is isolated from the main source by a transformer or other device.