MikeD wrote:GlennD: Isn't there a danger in using "double wiring" (if I am correctly understanding you mean two separate wires are used for part of a circuit instead of just one) that the current can rather easily become unbalanced between the two wires? As an example, if a total of 30a is passing thru the two wires, assuming the wires have initially exactly the same total resistance, then 15a passes thru each wire. But if one (wire A) degrades differently over time such that it eventually has, say, twice the total resistance of the other (wire B) then the current flowing thru wire B will be twice that of wire A, i.e. approximately 20a versus 10a -- i.e. isn't there the very real possibility of eventual heat damage to wire B's insulation? Or am I misunderstanding something?
You might think that, but it's done all the time in high current situations
It one of the commercial buildings I work at for the main feed wire they had like 6 wires for each of the phases, 24 very heavy wires in total
I believe how it works is as long as the wires are similar in size the current will balance between the wires, if say one wire gets a bad connection and starts heating up, it's resistance goes up and current is routed through the other wires(a good thing) as without the other wire/wires, the wire would keep getting hotter and hotter, possibly resulting in a fire or melting of the bad wire.
Whitney probably knows the code but I believe for smaller gauge house wiring, your not allowed by code to double up the wire, things that are plugged in like a EVSE probably go off a different code.