The discussion has been:
> Is 12 guage wire going to be enough?? I think I have 0 gauge wire in
> my 100amp alt. installation
> I have ... used just a 12 gauge wire...
12 gauge wire can safely carry up to about 20 amperes (I don't have
my book with the specific numbers) at 120 volts. Voltage is important
because if you lose 5 volts at 120 you still get 115 but if you lose 5
volts at 12 you get 7 which is a problem...
Voltage drop is simply amperage times resistance. If the wire is, say
0.1 ohms then at 10 amps you'll drop 1 volt.
The bigger the wire the lower the resistance. The longer the wire the
higher the resistance.
So you want the greater (i.e. heavier; lover number) of wire that is heavy
enough to take the current AND heavy enough to minimize voltage loss.
12 gauge, IMHO, is too light to meet the first criteria no matter how
short, and certainly too light if the run is of any length.
If the battery is mounted remotely (i.e. trunk) you need heavier wire just
because the distance is greater (therefore more voltage drop).
-- John
John F Sandhoff sandhoff@csus.edu Sacramento, CA
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