Nick,

A simple solution is to simply use 12-gauge for any length greater than 20 feet. Even at 60 feet, 12-gauge copper wire has insignificant resistance.

For lengths less than 20 feet, 14-gauge is fine, and for short runs 16-gauge presents insignifcant resistance.

Regards,

Alan

Alan Lofft,
Axiom Resident Expert (Retired)