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There is a single run of cable that needs to be replaced; all of our wiring is aluminum. I want to use cable with copper conductors instead of aluminum if at all possible. The run goes directly from the main panel to a duplex receptacle, which has another run of aluminum that goes to a single throw light switch. I was thinking of buying an electric outlet that is rated for both Cu and Al, connect the (Al) short run from the light switch to the top terminal screws of the duplex, and then connect the (Cu) home run from the breaker box to the bottom terminal screws.

Is this okay to do? Thanks to anyone who can provide an answer.

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    Have you worked with AlumiConns before? Oct 24 '20 at 14:56
  • Have you considered AFCI breakers? (if impossible, AFCI receps in junction boxes right next to the panel)? AFCI detects arc faults which are the #1 thing you worry about with aluminum wire on copper terminations. Oct 24 '20 at 18:02
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I think that's going to be your best bet. Splicing aluminum to copper is the issue, you need special connectors and hear all kinds of horror stories. If the connection is through the receptacle, and the receptacle terminals are rated CO/ALR, you've walked around the trap.

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    Thanks, batsplatsterson, that's definitely the route then. Greatly appreciated.
    – user
    Oct 24 '20 at 13:21
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    The correct rating by the way is called CO/ALR (the old, bad, original Cu/Al rating for 15A/20A wiring devices shouldn't be available any longer, but eBay has a bad habit of dredging up such garbage...) Oct 24 '20 at 14:56
  • Addt'l reference - diy.stackexchange.com/questions/94747/…
    – Freiheit
    Dec 22 '20 at 19:30
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I want to use cable with copper conductors instead of aluminum if at all possible.

You really can't buy aluminum branch cable anymore, so copper is your only route here.

I would suggest going the extra mile here and buying some Alumiconns and converting to copper (they can be bought in 2-packs if you don't want to buy more than you need right now). Contrary to batplatsterson, I've actually found them decently easy to work with AND you permanently fix the problem so you can use copper wiring and fixtures anytime afterward. What he's likely thinking of are the Noalox-filled wiring nuts (they're purple), and those don't prevent the arcing risk of twisting the wires together.

That having been said, I did have one outdoor project where I did use a CO/ALR outlet to convert to copper, and I've not had any issues with it since. Still, I want to go back sometime and put Alumiconns there so I can get a proper GFCI in (no GFCI outlets are rated for aluminum).

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  • I have used the Alumicons, they're OK but I'd still go with the recep any day. The Al rated receptacle accomplishes the exact same thing without the bulk of the Alumicon in the box, and aluminum wiring usually also means cramped boxes. Oct 24 '20 at 16:11
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    AA-8000 Romex is legal to sell and use today, but probably nobody stocks it. Oct 24 '20 at 16:42
  • I agree with bat re: the CO-ALR recep is not worse than Alumiconns. Near as I can tell, the CO-ALR lugs are aluminum. Oct 24 '20 at 18:02
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    @Harper-ReinstateMonica Actually, CO/ALR coats the lugs in Iridium to avoid oxidizing the aluminum or copper.
    – Machavity
    Oct 24 '20 at 18:22

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