Aluminum Wiring options.

[Steve in Virginia]

My wife and I are remodeling a bedroom . Our home was built in 1974. At the time the electrical code allowed for use of aluminum wiring because of the excessively high cost of copper at the time. When we first moved in, every light switch and outlet was replaced with CO/ALR devices and the wires coated with a no-ox compound. (Yeah, we found a whole bunch of Cu-rated switches and outlets with all the accompanying snap, crackle and pop of flukey Cu-Al connections). And no the house didn't burn down - fortunately. Obviously, aluminum wiring is not to code any longer, and yes, I've considered re-wiring the house with copper.

Now here's my quandry - I'd like to add recessed lighting, dimmer switches and two new outlets to the bedroom. Of course all those devices are rated for Cu wire. What are the options for interconnecting Cu wire to the existing Al? I I know I can use COPALUM connections ($35-$55 per connector -ouch!). Or can Ideal #65 Twister connectors be used, if available?

COPALUM would be easier than re-wiring the house. Then again a re- wire would allow me to hook up each room in the house with one or more dedicated circuit breakers. That way I could work on, say, a bathroom fixture without having to kill the power on half the upper floor. Any suggestions, or have I already answered my own question?

Thanks in advance,

Steve

"If we knew what we were doing, it wouldn't be called research, would it? " Albert Einstein

[RayV]

Sorry about you troubles. You might want to stay away from the Ideal

65 the 3M scotchlock is a better alternative If it were me (I also have Al wiring) I wouldn't pigtail or 'upgrade' any circuit. Any chance you get replace with copper.

You will be told by others here that Al wire is not outlawed and is used in transmission lines and for big appliances such as AC and ranges every day (true). You may also hear that Al is no more dangerous than copper if installed by a licensed electrician (false). Why take a chance? Al is much less forgiving than copper and not worth the risk.

[Joe]

[RayV]

Stay away from the Ideal 65

has a product that MAY be better

[William.Deans]

Greetings,

If you already have cu/al receptacles in your bedroom simply replace attach an aluminum wire to one set of terminals and a copper wire to another set of terminals. Do all of your upgrades off the copper. $35-$55 per connector is outrageous.

Good Luck, William Deans

[dpb]

And they only _thought_ Cu was expensive... :(

...

Beyond the other suggestions, if you have place for it (it would have to remain accessible, of course) a junction box w/ a Cu/Al-rated terminal strip could be used as the junction and the feed from there.

Unless it were extremely difficult, it would seem the better, longer- term solution would be for new work to be a new circuit run or take the opportunity to rewire this circuit now if that's in the longrange plans, anyway.

[RayV]

There are also these connectors

requested a sample and they are not much larger than a red wirenut but the wires obviously go in the side.

[Jack]

Looks like you've timed this cycle perfectly again where copper prices are going through the roof!

[Steve Barker]

they're actually on the way back down. 1000' of 12-2 is about half what it was 4 months ago. Still high, yes, but on the way down.

[LayPerson Tom]

imho:

I've been hearing some negative stories about the AL/CU Wire nuts. Not that the wire nuts are bad, just that it its design can make it easy for a person to improperly use them. So not that it's a bad product, that untrained people can really mess it up. So..... I've been looking into AlumiConn. If you use them, please post what you thought about them.

tom @

[Joe]

But is it as safe and reliable?

It looks like you have.

Residential rewiring is naturally much trickier tha new construction. But many journeymen have neat tricks that solve the problems you will encounter. For example, using an old cable to pull a new one into pace can stymie you if the cable is stapled to the stud per code. The old timers get around this by making a small opening in the wall and locating and prying out the staple. This often allows a fairly long new run to be pulled into place. Some horizontal runs through holes drilled in the studs may resist all efforts to move them, So they are left in place and new runs made by removing wall material sufficient for the wire to pass and a protective plate installed over it before the wall repair is made. For a DIY person a fiber optic scope might be useful, but I don't know of anyone that has tried one yet. HTH

Joe

[Dave Martindale]

A related but slightly different question: The 15 A branch wiring in our home is all copper, but the stove and clothes dryer circuits are 6 and 8 gauge multi-strand aluminum. As I understand it, there is less concern about multi-strand cables, I assume because the terminals are all screw terminals (no push-in connections) with the force spread over a large surface area.

There is no sign of overheating or corrosion problems at the circuit breaker end of these cables; I haven't checked the other end yet.

So, are multi-strand heavy-gauge aluminum cables still basically safe? Should I check both ends just to be sure? Or should I try to replace them with copper? (The latter will not be easy; the entire length of the cables is behind finished walls and ceiling).

Dave

[Bud--]

The whole paper at:

the best information I have seen on options for aluminum wire. The information is the result of extensive testing of aluminum connections for the Consumer Product Safety Commission, which apparently tried to recall aluminum 15 & 20A branch circuit wire.

I would probably pigtail using scotchlocks and the *detailed procedure* in the paper.

More information, much of it derived from the CPSC, is at the wider link:

link has very limited information on the AlumiConn connectors in a couple other posts.

A major problem with aluminum connections is a very thin oxide layer that rapidly forms on aluminum surfaces. The layer is an insulator and transparent. The "procedure" in the paper removes the oxide layer. The screws on 15/20A receptacles may not bite through. Wirenuts won't reliably bite through either. The AlumiConn probably will.

The problem has been on 15 & 20A branch circuits (where aluminum is still permitted but seldom if ever used).

-- bud--

[Bud--]

Push in ("backstab") connections for 15/20A branch circuits were never legal for aluminum wire.

I believe stranding is not the difference. The connections use screws that bite into the aluminum and deform the surface which gets through the insulating aluminum oxide layer. There is advantage in not spreading the force.

Another problem with aluminum wire is aluminum expands faster that most metals which can result in loose connections. Because of 15/20A branch circuits problems the alloy was changed about 1974. Receptacles and breakers should be listed for aluminum wire, which minizes expansion problems.

I would use antioxide paste at all connections. You might want to check tightness occasionally. If I had aluminum stove or drier wire I wouldn't worry about it.

-- bud--

[Dave Martindale]

Perhaps not, but I have seen a 15 A receptacle in someone's house that did use the rear push-in connections for solid aluminum wire. Though illegal, it did happen. (This receptacle showed signs of overheating clearly visible on the front face, and I suggested replacing it with a proper AL-rated receptacle before he had a house fire).

As I understand it, the problem is that these push-in connections apply high force in a very small contact area, and the aluminum simply cold-flows away from the contact point until there's almost no contact pressure (and a high resistance connection). In comparison, screw connections on outlets or the clamps used on breakers spread their clamping force over a much larger area, avoiding cold flow.

Thanks. It doesn't look like paste was originally used, so I may add some when I inspect the stove and dryer receptacle boxes.

Dave

[Bud--]

Backstab connections have a spring contact so I doubt the aluminum could cold-flow away - the spring would follow. "Binding screws' on receptacles don't have enough pressure to always make a reliable contact through the oxide. They don't deform the wire as larger connectors do - cold-flow helps make the connection. Backstabs have not real high pressure on a small area on one side and the same pressure over a large area on the other side. Seems like a recipe for failure with aluminum.

All posts on this newsgroup I have seen on the subject (which I agree with) strongly recommend not using backstab connections with copper either.

-- bud--