Driving myself nuts with cable size calculation. The main consideration is the possible addition of a bow thruster at some time in the future. It will be powered by a dedicated battery bank in the bow, but I want to install cables to cater for the max amperage possible. With a possible draw of 350Amps from a bow thruster and a total run (there and back) of 40 feet, allowing a 10% drop (as it is an intermittent load, and possibly only for a minute or so) I come up with 2/0 cable. Its possibly overkill but the cost difference is only a buck + change a foot. As I am not building 200 Hunters, I can live with it.
This obeyed ABYC Standards;
"Conductors used for panelboard or switchboard main feeders, bilge blowers, electronic equipment, navigation lights, and other circuits where voltage drop must be kept to a minimum, shall be sized for a voltage drop not to exceed three percent”. (See Table B).
Conductors used for lighting, other than navigation lights, and other circuits where voltage drop is not critical, shall be sized for a voltage drop not to exceed 10 percent.” 188.8.131.52.7. (See Table C).
All input appreciated!!!!