I have 125 amp service, and bought two #1 AWG black-colored wires for the electrician to use in his replacement. I couldn't find a white wire that size, or bare copper. Neither at Lowes nor Home Depot.
In my search, I found somewhere that said you don't necessarily have to buy the same size conductor for the neutral wire. That the neutral wire has to be at least 70% the size of the hot wire.
Is this true? And if it is, what size in AWG would this be? And does the wire have to be insulated?
My state follows NEC.
Best Answer
The maximum current for 1 AWG used in power transmission is 211 amps.(source) 70% of that is 147.7 amps.
2 AWG is rated at 94 amps, and 3 AWG is rated at 75 amps.
So there is no smaller wire rated at 70% or larger. You'll have to use 1 AWG (or larger) for all wires.
You could try an electrical supply house for other colors of 1 AWG, but I've found they only sell big spools (250+ feet) of such wire.
Try contacting a commercial electrician. They often carry those big spools around and might be willing to sell you a few feet of it. Of course they'll also want to charge you a $75 delivery fee and a $95 installation fee, but you should be able to avoid the first by going to them to pick it up, and the latter by firmly insisting that you don't want them to do it. Standard counter is they'll tell you it is illegal/dangerous/immoral for you to do it yourself. Stand your ground.