46 CFR § 58.25-65 - Feeder circuits.
(a) Each vessel with one or more electric-driven steering-gear power units must have at least two feeder circuits, which must be separated as widely as practicable. One or more of these circuits must be supplied from the vessel's service switchboard. On a vessel where the rudder stock is over 23 centimeters (9 inches) in diameter in way of the tiller, excluding strengthening for navigation in ice, and where a final source of emergency power is required by § 112.05-5(a) of this chapter, one or more of these circuits must be supplied from the emergency switchboard, or from an alternative source of power that—
(1) Is available automatically within 45 seconds of loss of power from the vessel's service switchboard;
(2) Comes from an independent source of power in the steering-gear compartment;
(3) Is used for no other purpose; and
(4) Has a capacity for one half-hour of continuous operation, to move the rudder from 15° on either side to 15° on the other in not more than 60 seconds with the vessel at its deepest loadline draft and running at one-half maximum ahead service speed or 7 knots, whichever is greater.
(b) Each vessel that has a steering gear with multiple electric-driven power units must be arranged so that each power unit is supplied by a separate feeder.
(c) Each feeder circuit must have a disconnect switch in the steering-gear compartment.
(d) Each feeder circuit must have a current-carrying capacity of—
(1) 125% of the rated full-load current rating of the electric steering-gear motor or power unit; and
(2) 100% of the normal current of one steering-gear control system including all associated motors.