46 CFR § 111.75-1 - Lighting feeders.
(a) Passenger vessels. On a passenger vessel with fire bulkheads forming main vertical and horizontal fire zones, the lighting distribution system, including low location egress lighting where installed, must be arranged so that, to the maximum extent possible, a fire in any main vertical and horizontal fire zone does not interfere with the lighting in any other fire zone. This requirement is met if main and emergency feeders passing through any zone are separated both vertically and horizontally as widely as practicable.
(b) Machinery spaces. Lighting for enginerooms, boilerrooms, and auxiliary machinery spaces must be supplied from two or more feeders. One of these feeders must be a ship's service feeder.
Special requirements for emergency lighting, feeders, and branch circuits are in subpart 112.43 of this chapter.