Mix and match might work for some things. However, it does not make for a pretty or safe sight when working with electrical wiring when circuits include both copper and solid-strand aluminum wiring. The panel below has both -- mix and match. The terminal on the left clearly has a solid aluminum wire on the top breaker. The ones below that are copper. Solid-strand aluminum branch wiring, used for a relatively brief period into the early 1970's, has a history of safety problems. I have seen estimates that a home could be as much as 50 times more likely to have a fire when such wiring is present.
The photo to the right is the same panel, viewing it from farther away, and at that location some odd work was done. They cut many of the aluminum wires off, and then they used wire nuts to splice copper pigtails onto the aluminum. The copper went to the breakers so, in glancing at the breakers, one saw mainly copper but looking at the grounds or neutrals one saw solid-strand aluminum in abundance. This makes it all more confusing but it does not resolve the issue with the solid-strand aluminum wiring. And it makes each connection at each wire nut suspect -- dis-similar metals in contact. They do make wire nuts, that they say are designed for this purpose of joining the two different materials together but, even those are suspect as far as any long-term repair. In almost all cases, the recommended cleanup procedure is eliminating the solid-strand aluminum wiring. Sometimes, an electrician might use special pig-tails but for those to be done right it is not cheap. Also, the problem does not exist only in the panel. Those aluminum wires attach to switches, outlets, lights and often, when viewing those locations, corrosion will be apparent. A home inspector, when confronted with this issue, directs the client to consult a licensed electrician for repairs and further evaluation. Steven L. Smith Bellingham WA Home Inspections
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Steve, that whole set up is some seriously bad ju-ju. Like you indicated, similiar concerns around the rest of the house seem highly likely. Some might have missed that one.
Charlie,
Your earlier blog on this topic was tops. People should check it out for some shocking photos.
Aluminum wiring is like a disaster waiting to happen. Glad none of the homes I ever purchased in the past had aluminum wires.
Sean Allen
Thanks for the info. It will be nice to be able to refer back to this post if I come in contact with an aluminum wiring problem again.
Why not just add AFCI breakers to the panel?
Mike,
If that is what an electrician wanted to do, to fix it, then he or she can tell my client that. I have not yet, even once, had any licensed electrician around here suggest that. Personally, some of the wiring I have seen, corroded aluminum, I would sure not recommend that. It is like putting a band aid on a cancer. Also, my research and some personal experiments, have not given me faith in AFCI breakers. I do agree with using them, but I do not trust them very far as far as being the primary defense against bad wiring. I think the repair should start with safe wiring, then add the AFCI for extra safety. Ever read the comments at Mike Holt forum? They have since revised this slightly, saying that the AFCI is better than nothing but they are not enthusiastic about them.
http://www.mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_-_Why_I_Have_a_Problem_With_It~20020801.htm
Steve
I have used them and in a case where the house had aluminum wiring in it the (new) breaker worked. Service upgrade and I used AFCI's rather than re-wiring the home.
It helped me find a 'flying splice' that I would never had found.
Also remember that most entrance cables are aluminum.
PS yes I have read Mike Holts forum.
I was member # 68. There are 46,739 members now.
Mike,
Yes, I was speaking of, as stated, the solid-strand wires at branch circuits. Around here the majority of entrance cables are aluminum. Thanks for the comments. Again, if that is what the electrician decides to do, that is fine but I want the licensed professional to make that determination so he or she is giving the best advice, not me.
Steve
I agree with you. I believe that AFCI's can keep someone from having to rewire a home.
Here is our opinion in Ohio: http://news.cincinnati.com/apps/pbcs.dll/article?AID=/20080907/EDIT02/809070384/1019/EDIT
Should have thought of this before.
With both aluminum and copper in a home one place that no one checks is the junction box.
All EGC's (equipment grounding conductors ) must be tied together in a junction box. This could mean that both materials may be connected together.