Just caught someone using wire nuts on aluminum wiring in a panel

I was doing a service call in an older house off Elm Street last week and found a mess in the panel. Some handyman had pigtailed aluminum to copper wire using standard wire nuts without any antioxidant compound. That's just asking for a fire with that galvanic corrosion over time. I see this mistake way too often from guys who don't know aluminum needs special connectors or at least the purple wire nuts with goop. Even my apprentice knew better after I showed him the burnt up connection from a similar job. How do you guys handle explaining this to customers without sounding like you're just upselling them?

3 comments

3 Comments

the_olivia17d ago

Yeah, the "my father-in-law did it for years" argument drives me nuts too.

terryb1117d ago

Honestly, what gets me is nobody's talking about the insulation rating on those cheap wire nuts. Most people just grab whatever's on the truck, but standard 105°C rated nuts can break down way faster when you mix metals and add heat cycling. I had a guy argue with me for ten minutes that his father-in-law did it for thirty years without issues, but he was running a 60 amp sub panel on 50 amp breakers so the heat never got high enough to melt stuff. It's like the fire hazard lottery and some folks just get lucky until they don't.

claire_butler117d ago

Tell you what @terryb11, I've seen this exact thing play out on jobsites more times than I can count. Grab some 150°C rated nuts for anything mixing copper and aluminum, they're worth the extra few bucks. The cheap ones start cracking after a couple years of that heat cycling and you're chasing ghost trips and flickering lights. I always tell guys to just skip the argument and swap them out upfront, saves you a headache when the homeowner calls you back six months later. Your point about the father in law running on undersized breakers is spot on too, low heat hides a lot of sins until you actually load it properly.