I recently removed some hanging light fixtures from an older house and plan to use them in my house. Unfortunately, there is nothing distinguishing the two wires (black/white or ribbed,smooth) in the fixture so that I know which to connect to the wires in my ceiling.
Does it matter on old fixtures? How do I tell the difference? If I wire the fixture- and it happens to be incorrect- will it damage the fixture or just throw a breaker?
Any ideas?
It doesn’t really mater to any great extent; if you wire the lamp backwards, it will still function properly and the breakers will not trip. However, you will have created a small safety hazard, since the proper wiring result in the threaded part of the bulb to be connected to neutral (white) so you can’t get a shock while changing the bulb. If you want to do it right, either use a multimeter or a noncontact voltage sensor to determine which wire is hot (black or red), and then wire the new fixture accordingly. Otherwise, I wouldn’t worry about it too much, except to be sure the switch is off before changing bulbs.
If I am reading the OP correctly, it is not the wires, but the fixture, that is unmarked. There should be a brass colored screw and a silvery screw where the wires actually connect to the bulb holder. The brass colored one is hot (black) and the silvery one is neutral (white).
If you actually have wires that are still attached to the fixture, my thought would be to remove them (as old and not dependable), replacing them with wires you have purchased. To do that, you will need to open up the fixture to find the connecting point, where (if you are lucky), you will see the brass and silver screws.
(For that matter, you might want to replace the bulb-holding guts of the lamps, so you can buy your own new guts with clearly marked hot and neutral connections (and even, if your wiring supports it, the third ground wire).)
Yeah, I think i’m going to replace the entire socket for peace of mind. I think Q.E.D’s suggestion will work, but I’d rather have more current wiring.
FYI, the fixture is a hanging chandalier with one bulb socket.
If the fixture is that old, I wouldn’t count on it. In any case, if you have a multimeter, it’s very easy to tell which is which: put the meter in resistance mode (scale is irrelevant), and measure from the silver threaded part in the lamp socket to each wire; whichever wire gives you about a zero ohms reading will be the neutral (white).
If they are old cloth-covered wires look for traces of a bit of white paint along one of them-- there might be some crusty white goo left detectable.