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TIL that old timer at the supply house was right about using anti-oxidant on aluminum wire | Electricians - Opinions Matter

the_evan•3mo ago

TIL that old timer at the supply house was right about using anti-oxidant on aluminum wire

He told me last spring after my third nuisance trip on a 200 amp panel in Phoenix that I was getting false readings from a bad connection, and sure enough that paste fixed the whole thing, has anyone else had an inspector flag them for skipping that step?

3 comments

3 Comments

lisak263mo ago

Didn't an electrician friend tell me the same thing about oxidation on aluminum?

troyreed3mo ago

Honestly I'm gonna push back on that a little. Most of the oxidation issues people talk about with aluminum wiring were from the 1960s and 70s when they used a specific alloy that was more prone to it. Modern aluminum wire has way better alloys and connections that practically eliminate the problem. Plus the whole "oxidation causes fires" thing gets blown way out of proportion - copper oxidizes too, it just turns green instead of white. The real issue was always loose connections from installers not using the right anti-oxidant paste or torque specs. Tbh if you factor in cost savings and weight reduction, aluminum is actually a solid choice for big feeder circuits if you just follow the damn instructions.

the_james3mo ago

My buddy Dave out in Mesa had a 400 amp service inspection flagged last summer for the exact same thing. The inspector pulled the cover off and saw bare aluminum lugs on the main breaker, no paste at all. @troyreed makes a good point about modern alloys being better, but that inspector was old school and wouldn't sign off until Dave went back, cleaned every connection with a wire brush, and slathered on the Noalox. Dave was really annoyed because he was behind schedule, but he admitted later the lugs did look better with the paste on them, and he hasn't had a single nuisance trip since.