With the price of copper going up, and copper thefts making the news every day, what’s the likelihood of aluminum wiring making a comeback for brach wiring? I know that aluminum is used for high-amperage circuits today. My house was built in 1970, and it has aluminum wiring. When I bought it in 1994, I spent $1,500 to have all the ends terminated in Amp’s COPALUM system. Everything has been fine since then.
God, I hope not. Aluminuim wiring is a pain in the posterior.
Agreed. Aluminum is perfectly fine in the hands of experts who know how to terminate, connect and maintain it. We’ll have a huge rash of home fires when every Joe Handyman starts messing with it and they do dippy things like connect it to copper under a normal wirenut, assuming they use a wirenut at all. I’ve seen far too many times where someone just gave two wires a couple twists and wrapped it with electrical tape. Often, the connection is so bad that it warms up and the tape melts. :eek:
One of the ratings factors on my homeowners insurance was whether or not there was any aluminum wiring in the home aside from the service drop, so I’d expect some pretty stiff resistance from the insurance industry against bringing back aluminum for in-house circuits.
Key words there. Even properly connected and terminated aluminum wiring can work loose over time. My mother’s house is fortunate to still be standing, with no less than three recepticles shorting out or developing high-resistance contacts at one time or another.
We had a professional go through the hous and pig-tail all terminations. All aluminum that could be stripped was stripped out. I was trained to do this stuff in the Nav, but aluminum makes me sufficiently paranoid that I won’t touch it if I can avoid it - I’ll pay for a professional who’s current in his practice, first.
pun not intended, but acknowleged.
Is THIS a pun?
I doubt it will come back for home wiring. I replaced all aluminum wiring when I purchased a home. It’s a good thing the electrical boxes were fire proof, because three outlets were fried. One had no insulation left on it for 6 inches in all directions from the outlet. One had only a the front of an outlet attached to the face plate, because the back half had been burned away. I wouldn’t stay in a building wired with aluminum.
What about copper-clad? It was supposed to be just like copper in it’s application, and cheaper.
Can one of you knowledgeable people fight my ignorance - what’s so bad about aluminum wiring? I see from this thread things like fried outlets and connections working loose - what are the actual differences between aluminum and copper that make aluminum unsuitable for house wiring?
Can you explain this for those of us ignorant in the dark ways of the electric? Why is aluminum any more difficult to deal with than copper? Why does it make you paranoid?
Copper develops a conductive oxide. Aluminum develops are very hard (think Sapphire) non-conductive oxide, and it happens very fast. Any bare aluminum becomes non-conductive quickly, making high-resistance connections. Also, aluminum tends to “creep”, meaning that the connections tend to loosen up over time. All of these things mean that aluminum must be connected with much greater care than copper, which is pretty tolerant of mistakes. That said, Aluminum is used for high-current cables all the time.
Aluminum expands significantly when heated. So when aluminum wiring is placed under load, it expands, loosening the connection points. Remove the load and the wire returns to its normal size, but the connection is now loose. Do this often enough and you’ll get a gap and significant arcing.
Creeping, working, shrinkage, and non-conductive oxides, as mentined above, are all important reasons. Anything that tends to make connections unreliable is bad enough in a professional environment, where they’ll get regular maintenance and inspection. But there, they will get maintenance. When was the last time you heard of a homeowner popping open all the junction boxes, recepticles, wall swrtiches, lights, and any other fixuture in a house, for the purpose of inspecting the connections? One bad connection, left unattended, can burn a house to the ground. As I mentioned above, my mother’s house had three such incidents. Fortunately, she’s smart enough to call me when things get weird, and I’m smart enough to pop the master breaker until the problem is found.
In addition to the above, aluminum tends to ‘work harden’ as it ages, becoming brittle. That makes it harder to add, remove, or replace fixtures.
“Pig tails” are special transition wires that are a blend of alloyed metals that transition from the aluminum at one end to copper at the other end, transitioning one to the other. That removes the short at the fixture problem, but not the rest of the connections in the house, many of which may be completely hidden, thus uninspectable, and thus unknown fire hazzards.
Technically no splice may be “hidden”. If it’s wired per NEC. I understand what you mean when you say hidden though, not everyone understands that there may be splices in the box above the fixture or hidden in a J-box under the insulation in the attic. Those splices that are hidden from plain view may be hidden to the casual observer, but not unserviceable.
Correct, though I will note that the NEC is not always followed. My mother’s house looked like it’d been wired by drunken monkeys on crack. Don’t ask me how it passed any inspections - I’m perplexed too. Yet another reason to get a professional - they follow code, on pain of official sanction.
Also correct, and this is the greater worry - people, not realizing that they’re there, will simply not go looking. Well, they don’t look anyway, but you’ve clearly already figured out what I mean.
I doubt that it will ever come back. It is deficient, dangerous and I believe not up to code.
So, why did they use aluminum in the first place? Obviously it’s cheaper than copper, but did no one foresee the problems? Was there no testing before the manufacturers started churning out miles and miles of aluminum house wiring?
Was it done due to wartime copper shortages or for some other reason?
ETA: As a historical sidelight, the peak of the Washington Monument was made out of aluminum, because at the time it was very rare and more valuable than gold.
Pretty much, no, there wasn’t any comprehensive long-term testing. It never occured to anyone that there were down-time problems. And it was cheaper. Only time and experience showed the problems.
Aluminum wiring is unlikely to come back, for several economic reasons:
- electricians don’t like it. It is harder for them to work with than copper, for reasons mentioned above. Especially in renovations or remodeling. And it’s riskier for them – aluminum wiring tends to have more fires, and then electricians being sued. (Many electricians will refuse to work on aluminum wiring unless you rip the circuit out and replace it with copper back to the breaker box.)
- Builders, Insurance companies, Fire Departments don’t like it, because of the requirement for more careful installation, and the tendency to cause more fires.
- aluminum is used much more for other purposes nowadays. Just the soda pop can market needs much more than electric wiring.
- there is an extensive copper recycling system (which is why thieves steal copper), which increases the supply of copper. Before the Bell phone system split itself up, their recycling system was a larger producer of copper than any of the copper mines. (According to a Bell System worker; I don’t know if that is completely accurate.)
Aluminum wire used to be so much cheaper than copper that it was worth the extra labor costs needed to install aluminum wire. As copper wire has come down in price compared to aluminum, and electrician labor rates have gone up, that is no longer true. So there is no advantage to using aluminum wiring any more.
As others have mentioned, the primary problem with aluminum wiring is “creep.”
Aluminum wiring can be made safe if the right interconnection technology is used. You know the service wire between the transformer on the pole and your house? Aluminum wire. Or the wiring between the generator and main breaker panel on a military aircraft? Aluminum wire. Or high voltage/high tension lines? Aluminum wire.
Airbus is using copper-clad aluminum wiring in one of its latest jets. So I can only assume the interconnection technology has reached the point where copper-clad aluminum wiring is safe.