Wire sizes, plugs, and sub panel

[Rob Russell]

Chris,

I just checked with our local orange borg.

2-2-2-4 aluminum SER is good for 75 amps and costs $1.49/foot.
6/3 copper NM (aka "Romex") is good for 60 amps and costs $3.07/foot.

[Buck Williams]

Aluminum wiring gained a bad rep in the late 50's and early 60's when it was used to wire houses in #14 and #12 gauge romex. Aluminum in that size couldn't handle the thermal expansion at the termination point of switches, receptacles and fixtures and created a fire hazard. Since that time aluminum wire cannot be manufactured in any size smaller than #8 gauge. #8 and above is acceptable per the NEC code for branch circuits in commercial and residential applications. Of course local codes, specifications and interpretations do apply. It's common, for example, to see aluminum SER cable used in a residential application to feed an electric range to avoid the higher cost of copper. Copper is by it's nature a better conductor, but aluminum if installed properly will not create a problem. I doubt that there is an electrical utility in the nation who is feeding their customers service with copper instead of aluminum and you don't hear of a high percentage of failures of fires. Not pushing aluminum over copper, but if cost may be a factor, aluminum could be an option. Not an electrician, but I've been around the industry for a few years. Just my $ .02 on aluminum wire.

[Rob Russell]

Buck,

Well said.

Rob

[Rollie Meyers]

In reply to those who think that the NEC prohibits aluminum branch circuit wiring, there is no such thing, if one were to find some new old stock 10 & 12 AWG aluminum of the correct alloy (early 1970's NM AL cable is the modern alloy), there would be no NEC issues, but being able to do so does not make it a good idea. I don't care for AL used for loads under 100A, just my opinion.....