i had to remove a couple of light fixtures for some drywall repair i was doing. the fixture was hooked up to a hot-neutral aluminum wiring AND a hot neutral copper wire. i think the other fixture had same wiring. have these fixtures been pig tailed? if not, what should it look like? thanx!
you should NEVER pig tail copper to aluminum ! ! !
I had a home with Aluminium wiring. This type of wiring is safe if you take certain precautions: Aluminium wire is more flexible, but more fragile, so handle it more delicately than you would Copper. Use only Aluminium connectors with Aluminium wires. Fixtures should have a symbol printed or moulded into them with Al in a circle. If you see Cu in a circle and Al in a circle with a slash across, that means it is not for use with Aluminium directly. You can connect Copper wires to Aluminium wires if you use special connectors (#33) AND a special paste. Your local home centre should have both.
The only way to connect copper to aluminum and limit the possibility of fire is to use split nuts which can be bought at an electrical supply store. While you are in the store, get some anti-oxidant. The main problem with a split nut is that they will be large and you will have at least two of them per box and most boxes are too small for this. Wire nuts are not the thing to use. There is a method that is approved for this, but the electricians have to be specially trained and that cost a lot of money, so they avoid it. They have to rent the tool to do it from the manufacturer and they want something like $8000 as a deposit to rent it, so an electrician who can do it will be expensive.
It is very common in older homes to have tin coated copper wiring which many people then think they have aluminum wiring. If you have a piece of the older wiring or can turn the breaker off to one of these wires use a screw driver to scrape at the wire on the bare end; if it's tin coated copper you will see the orange/rust color of copper after a few light scrapes, the scaping is nothing agressive. This will determine if you have aluminum or not. Someone else mentioned about a loose connection which if a copper wire aluminum wire are connected together it would very likely fail creating a short. The two different materials expand contract at different rates which creates a bad connection. There is a special crimp process that can be done to join the two but a electrician should definately do this. A lot of the older homes just have two many items all on one breaker. With what you've described I would suggest using a electrician. Additional: If no breakers are tripped off and you do not have power in some areas you might have another panel (sub-panel) somewhere else in the home OR this circuit is hooked up to a GFI outlet somewhere else such as the kitchen, bathroom or garage. I would physically re-check each breaker and then hunt for a GFI outlet and sub-panel.
