The first line of defence for electrical wirings should be the
installation. Don't have wires that are permanent lying around lose and
unprotected that can get nicked, cut or worn in the normal operation of
the boat. I try to run power cables in plastic electrical conduit
=B9=82=B2=82=B3 where I can and wire tie out of harms way where I can't. =


In the case of a trolling motor that is installed in the open, the
cables should be lashed out of the way. They should not be laying on
the deck, for instance, where you could drop a portable steel gas tank
on them.

As someone pointed out, "most"=A0 devices will open up (but don't bet on
it) under the strain of the hundreds of amps a battery will deliver when
short circuited. If you have a need to fuse, and you certainly should
on a permanent installation, use an automotive fuse link (more reliable
than a mechanical breaker especially in a wet boat) at the battery.
They are rated around 100 to 300 amps and will blow if the cable is
shorted and will not blow from the normal load.

My opinion, worth what you paid for it.

Ron

Notes

1. Power cable in conduit has to be over rated, depending on the number
of conductors, because of reduced heat loss. Consult an electrician.

2. Cables are rated for max load at a max surrounding temperature
(usually 60=B0 or 90=B0 C). A cable rated for 100 amps will carry many
times that before it fails.

3. Marine cable is available with a SS braid for armoring. Its easier
to install than conduit. Don't remember what the standards say for
shipboard but I prefer National Electric Code rated conduit.