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Aluminum wire --Again

835 Views 4 Replies 4 Participants Last post by  Old Thomas
Read an interesting article at I believe it is building inspector site. At the end, the summary is "don't half way fix the problem. Do it right with proven procedures and material". I also read an article about using the CO/ALR device for switches and receptacles. BUT---it recommended not using the early ones that have "dark rough finish" screws . Use the newer ones with a more shine finish. WHAT? I think my head is going to explode. So the few I used 8-10 years ago are no good ?

So my future changes or updates will be with ALUMICONN connectors with copper pigtails and copper devices. I also purchased a torque screwdriver. Today I opened a single outlet that has ground wires twisted with a wire nut (30 years old?). The wire nut was used to secure an aluminum ground pigtail leaving the twisted grounds going to the receptacle.

1. When aluminum grounds are twisted together, is there an alternative to the expensive and HUGE purple wire nut?
2. If I need a piece of aluminum ( 12 ga. or 10 ga.) wire for pigtail, where can I find it?
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Aluminum and copper both oxidize in air. Copper oxidation is a conductor, aluminum oxidation is an insulator. Aluminum flows easily when hot, copper does not. Aluminum connections in air will oxidize, then get hot and the wire will flow away a tiny bit. Then when it cools there is room for more oxidation and the cycle continues till it gets too hot. Connections should be clean and greased to prevent air from contacting the wire at the connection. Special (expensive) wire nuts have grease inside and a skirt to reduce air infiltration and to keep grease inside. At fixture screws of AL approved devices, grease the wire, tighten the screw, then make sure grease covers it so no air gets in. Done properly with the correct materials, you will not have problems.
First, aluminum wire was used primarily from 1965 to 1972. The Vietnam War used a lot of copper, so wire went to aluminum. A house built in the 80s would be unusual with aluminum. I suspect that the house is older.
If the walls are open it would not be hard to rewire. I would not demo the walls just to rewire, though. Done correctly, aluminum is ok. Just remember that one size heavier wire is used with aluminum. For example, a 15 amp circuit uses 14 gauge copper but it uses 12 gauge aluminum.
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