How to identify aluminum wiring?

Question

I'm in contract on a house built in '75, and I don't want to have the same issues I had last time and waste money on inspections...is there an easy way for an amateur to see if there's aluminum wiring? Can you tell by removing an outlet cover and looking at what's inside? I don't know if I should be messing around with the panel. Thanks.

Kevin C. · Answer

Now that you mention it Marc, I recall the only concern back when we had aluminum wiring was the wiring in the house.   Regardless of the feed (copper or aluminum), all I remember is that aluminum in the house was not so great.

I remember if I had to change a switch or outlet, I had to buy the pieces specifically designed for aluminum, and they were always at least twice the price of an outlet for copper.

We never had a problem with the wiring, but we were only in the house a few years.

These days, I'd avoid a house with aluminum wiring (not the feed, but the wiring throughout the house)  I just don't want the additional risk associated with aluminum.

Kevin C. · Answer

I had a home with aluminum wiring back around '80.  If you pull a switch or outlet cover you should be able to see the wire, aluminum will be aluminum in color.

Some homes that were wired with aluminum have been converted to copper.  The conversion may be just a pigtailed length of copper onto the existing aluminum wire, then the copper wire is connected to the switch/receptacle.  I believe there was a salve of some sort that was supposed to be put on the aluminum to copper junction.

Wall switches and outlets designed for aluminum wiring will be stamped CO/ALR.

I'm not an electrician, just posting up some of what I remember from back when I had a home with aluminum wiring.

Edit to add:  Based on what Charles posted, I'll add that I believe the main feed to our house was copper, then aluminum was used to wire the house.  I have no idea if that would have been the norm.

Marc Freislinger · Answer

Charles,

Don't most homes have aluminum service wires? Every new service I've installed does. They are much cheaper in the 100-200Amp sizes, and when installed properly, are completly safe. Is that not standard throughout the country?

Account Closed · Answer

It's very easy to take the cover off the service panel and you can quickly see what kind of wiring you have.

The problem with checking an outlet is that it won't tell you what your service wires are made of.  A home could be wired with copper and have aluminum wires servicing the house.

Steve Babiak · Answer

Marc,

I agree with your point on the main service lines being Al in most cases.  Use of "no-lux" anti-oxidant on those connections involving Al wiring is advised.

Bienes Raices · Answer

Thanks. What should I look for when I remove the service panel?

How to identify aluminum wiring?

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