Don Mahony wrote:
I am installing a Lewmar Horizon 600/900 horizontal windlass on a 27
foot power boat. The users manual says to use #4 AWG marine grade wire
from the battery to the solenoid to the breaker to the windlass and
back to the battery. The wire leads on the windlass are #10 AWG.

I know the concern here is with voltage drop to the motor but the cost
of the #4 wire is huge. Rather than following the general guidlines in
the manual does anyone have a better way of calculating exactly what
gauge wire would be needed for this installation?

The total run from the battery to the windlass and return is 72 feet.

Don

Don,

The #4 sounds like over kill, and you wire run is not back and forth,
it's from point A to point B. My old boat was 27 feet, my power winch
called for #6, much cheaper than #4. It worked perfect, that winch is
being used occasionally, not constantly. If it were being used for
extended periods of time the larger wire would be justified.