"Copper Only" Recepticles?

[TaskBoy]

Hi all, this is my first post. Anyway, I am about to replace some 110 recepticles in our home and want to know how important it is to NOT to mix copper-only recepticles with wire aluminum wiring and why? I didn't notice the labels until I got home. Thanks!

[Tom R]

I don't know the exact answer, but do know it is VERY important! A definite FIRE HAZARD! You need to return them and purchase Co/Al or just Al. receptacles, depending on if your wiring is 'mixed' or just aluminum. If you don't go by these rules, you're home insurance, if not your family 'preservation', is nullified. Two 'dis-similar metals contacting each other cause a galvanic reaction, followed by a corrosive action, leading to 'separation' of the connections, followed by arcing, sparking, then possible FIRE! Hopefully, someone else will chime in with more info.

[Sparks]

A galvanic reaction as well as different expansion and contraction rates of al. and copper which eventually causes a loose connection which leads to house fires. You may want to have a pro look at your situation and suggest the best course of action. There are a few different ways to go and it would depend on the condition of existing wiring, etc. If you opt not to replace the al. wiring, if it were me and my family lived there, I would at least install A.F.C.I circuit breakers in the service panel. These breakers are code now for bedrooms for new builds in some areas. The breakers will sense when an arc is taking place in the circuit and trip to interupt the power, possibly saving lives. Around here they cost about 20-25 dollars a piece but in my book are worth the bread. But when it comes to electrical I never take chances. Just don't confuse afci breakers with gfci breakers cause they're two different things with different purposes. Just some thoughts but without seeing your wiring and condition I wouldn't know the best approach. I suggest contacting a local electrician to be sure and let him take a look at your situation.

[Tom R]

Thanks for jumping in, Sparks. Good advice.

[Vector]

AFCI breakers will help in the case of a wire that has become loose and is arcing to the outlet/switch/etc, but will do nothing in the case where an oxidized wire is providing a high-resistance connection, and as a result heating up dramatically under load.

Having AFCI is however, much better than not having anything.

[mjpliv]

Two 'dis-similar metals contacting each other cause a galvanic reaction, followed by a corrosive action,

Its the same reason you cannot hang copper pipe using steel, tin or aluminum fasteners.

[N2Deep]

Just wondering why the Electric Company uses Alum. wire to connect the panel but requires copper for the house? The panel is not copper but still seems wierd for Alum to the transformer.

And one other thing that is new in the 2002 NEC codes that are just being enforced in my area are the "bubble" covers for all Exterior switches/outlets. You can no longer use the damp approved covers, but must be waterproof covers with cover. Heck I live in the desert and get about 4 inches of rain a year and outlets are under covered patio and still required to install these silly things @ $11 apiece.

Ooh well what can you do if you want to close and move in after construction.:)

[Rich]

We're using 500 cu lines for our service to the transformer - all the way to interior. Kind of a special case though being that it's a 1200 amp service.

[Vector]

Just wondering why the Electric Company uses Alum. wire to connect the panel but requires copper for the house? The panel is not copper but still seems wierd for Alum to the transformer.

There is nothing wrong with properly prepared, sized and terminated Al wire. It just takes the proper knowledge. Al is cheaper than Cu, and in large size wires, it's a big difference. Since (theoretically at least) the lineman knows his business, Al service wire is cheaper to use, and just as safe.

Inside the house where any bozo could (and probably has) messed with the wiring at some point, Al can be quite dangerous.