Originally Posted By: roconnor
This post was automatically imported from our archived forum.
Russel is correct that AL wire is permitted in new construction (unless there is a local restriction) down to AWG #12
for 15A circuits (Both IRC and NEC), although that is not common in my area.
The newer AA-8000 series AL wire is much better and doesn't have the same problems as the old style AL wire. But for a given circuit, aluminum wire still has to be larger than if it was copper. Also, the newer AL wire usually doesn't require the oxide inhibitor compound (see links below) as long as the connector is listed for AL, CU/AL, or CO/ARL (no marking means CU only).
The real hazard is older AL wire AWG #10 or smaller (which is solid, as #8 and larger must be stranded) in homes build in the early 1960's to 1970's with what is called "old technology" aluminum wire. Even AL wire up to a few code cycles ago had some issues, including AA-13000 series AL wire.
I would red flag any AL wire AWG #10 or smaller in any existing home that does not have the CU pigtails and special AMP compression type crimp connectors (no wire nuts). Even with the correct pigtails and AMP connectors, some home insurance companies may not insure a house with old AL wire, so be careful. ![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)
The following links have all you ever wanted to know about aluminum wiring but were afraid to ask ... lol ... including links that talk about terminating AL wire and CPSC #516 on old AL wire and proper pigtails. The first page of CPSC #516 also has a good section on warning signs to look for:
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong