46 C.F.R. § 169.688 – Power supply.

(a) The requirements of this section apply in lieu of subpart 111.10 of this chapter.
(b) If a generator is used to provide electric power for any vital system listed in § 169.642 of this subchapter, at least two generating sets must be provided. At least one required generating set must be independent of the auxiliary propulsion machinery. A generator that is not independent of the auxiliary propulsion plant must meet the requirements of § 111.10-4(c) of this chapter. With any one generating set stopped, the remaining set(s) must provide the power necessary for each of the following:
1. (1) Normal at sea load plus starting of the largest vital system load that can be started automatically or started from a space remote from the main distribution panel (switchboard).
2. (2) All vital systems simultaneously with nonvital loads secured.
(c) The adequacy of ship service generators must be demonstrated to the satisfaction of the OCMI during the initial inspection required by § 169.221 of this subchapter.