[C320-list] Early Catalina 320 Battery fuses

[Troy Dunn]

It is hard to make a recommendation because one would need to assume that
your wiring has not been changed in order to get it right.  When you fuse
at the battery you are essentially attempting to protect the wires feeding
the main panel and the starter.   IF those are 1/0 wires, my reccomendation
is to add 250A MRBFs to each battery.  There are other approaches you can
take.

For a general idea of fusing vs. wire size/type, google Blue Seas
Ampacity.  Assuming you are the original owner, or the PO didn’t attempt
some creative wiring, the largest cables attached to your batteries are 1/0
and 105°C rated.    Problematically there will be other cables (probably 4
AWG) attached to your battery that are not fused within the desired
distance.   Whether or not this is truly an issue is a matter of
debate...aren’t you glad you asked?  LOL.

The debate part is all about where you think a short to negative will occur
in your wiring.   Fortunately on a fiberglass hull the probability that
your 1/0 + wire will find some other circuit back to your battery -
terminal before it finds a fuse is pretty darned small...not zero
though...Hence the word probability.

For a whole bunch of great articles on this and many other topics, google
marinehowto.com.

Troy Dunn
Hull#514