@RichP said:
Sanity-checking those numbers: 100' of 12 AWG with a 10A load will drop 1980 Volts. That would mean 100' of 12 AWG would not work for wiring a household 120 VAC circuit.
That's the least sane sanity check I've ever seen; I was compeled to create an account just to reply to that. 10A dropping 1980V would require 198ohm, or 123,750' of 1.6ohm/1000' 12 gauge wire. There are at least two factor-of-10 errors in the analysis above that resulted in a 32mV drop. 100' (which is rather too long for a 20A run of 12 gauge wire, 10 would be better) of 1.6ohm/100' cable would have a resistance of 0.16ohm. 20A passing though that resistance would result in a volatge drop of 3.2V, or 2.66% for a 120V circuit. This is of course out of spec for a 2% drop, but in spec for a 5% drop, assuming all terminations contribute no resistance.