Wdeertz
Senior Member
I recently replaced my alternator and while doing so I noticed the wire looked a little light for the 120 amp alternator. I confirmed with the prior owner that the 120 amp alternator and 6 awg wire is original from the factory. I estimated the positive wire is about 15 ft and the negative is about 5 ft to the starter which from there continues another 10 feet on 2/0 cable. If I use my dc wire app for a 30 foot dc loop it shows I should be using 2/0 for the entire length with a 2.4% voltage drop. If I use a 10% voltage drop it shows to use 4 awg. I have a Balmar external regulator so could limit output to 90-100 amps which would sneak the 6 awg wire within limits.
The alternator is a 120 amp Bosch so not sure of the specs but suppose once warmed up it’s only putting out 90 amps or so. The alternator Wire didn’t have a fuse on it as my vintage boat didn’t require one at time of build but I plan to add one. I’d like to put a 150 amp fuse to avoid nuisance trips but then need to step up to 2 awg wire.
All inputs appreciated.
The alternator is a 120 amp Bosch so not sure of the specs but suppose once warmed up it’s only putting out 90 amps or so. The alternator Wire didn’t have a fuse on it as my vintage boat didn’t require one at time of build but I plan to add one. I’d like to put a 150 amp fuse to avoid nuisance trips but then need to step up to 2 awg wire.
All inputs appreciated.