Why are all the wires black?

Question

I took down a light ceiling fixture. There are 2 sets of 2 wires. All the wires are black. It's an old house so maybe age has blackened some of the wires, but why would all the wires be black? I know hardly nothing about electrical standards but I thought that for ease of repair and for safety ,certain colors had certain uses. I'm finding out that's not the case. I know I can find out if the wires are hot and so on, but I don't understand why all four wires connecting my ceiling fixture would be black. Thanks

Answer 1

Unless we have more information, you will only get generic answers and guesses. Granted, some of the replys so far have had important points, but only if you understand what they are saying. Most people would not because they lack the experience in working on old buildings.

How old is the house? What do the wires look like; does the insulation look like most electrical wires, like in the store, or is it much thicker? Is the insulation plastic or something else, perhaps that you can't identify? Is the insulation brittle or does it flex easily? Does it look like there is a thin cloth covering over the insulation? Are the actual wires discolored? Any burn marks in the box? Are there any white "things" in the basement or attic that look like wires used to be attatched to them or go through them?

I'm trying to see if this is an old, obsolete type of wiring that had only black insulation. That would explain your situation.

In any case, work on this is best done by someone who is very competent with a volt meter. It is important to insure that the power is definately turned off to any wire that you will work on. Simply turning off the switch is not good enough for safety.

Even turning off one breaker may not be enough. This is because there may be circuits that run past your light, but don't power it. You can turn off the breaker that controls the light, but does that breaker also control the other circuits that are in that box? You need to know.

Answer 2

Take a step back for a second on this. Where were the wires black? In the cieling or on the wall switch? Did you have the light on a wall switch? If the light was on a switch then the power source was direct to the light fixture and the white wires were marated to a black wire, maybe hidden in the fixture box. Check the switch and see if the switch has any white wire. What happens is the switch will have two wthie wires to it, both run up to the ceiling and get power from there. The light is "always supplied with power" it is only broken when the switch is in the off position. For any one out there doing repairs always turn off at the source, not at switches as you will be in for a surprise if you try shut off power at the light switch.

Answer 3

when i started working on my 1932 house the first thing i did was go to a home center and buy a roll of white and a roll of red electrical tape. i already owned a multi meter but i picked up a circuit tester that just plugs in to an outlet and indicates, with lights, correct wiring connections. old houses often have knob and tube wiring, black fabric covering black rubber insulation on the wires. anytime that i worked on a circuit i would determine which wires were hot and which were netural then mark the hot with red tape and the netural with white. the reason for the red as opposed to black was because everyone uses black tape and this way i would know which circuits i had worked on. the way that i would determine hot or netural, was to run an extension cord to a grounded outlet, then with the meter set to ac volts plugged into the ground terminal, touch it to each wire. if i got a reading, it was a hot wire and i marked it with red tape, if none were hot then i would filp the light switch and test again to determine the hot lead. it was a slow process and there might be a faster way with better equipment, but it works. also, a few bits of advice and or warnings; most of the old wiring was 16 gauge wire. the insulation gets brittle and crumbles easily, espesially the wires above ceiling lights, from the heat of high watt bulbs. if the procedures that i described are within the scope of your abilities then go ahead and repair your wiring, if not, be safe and call an electrician. good luck, hope things work out for you.

Answer 4

That's an easy one. Either it was wired pre-code era, or a DYI-er or unlicensed electrician did the wiring. That is the only reason why it would be that way. You don't necessarily need to change out the wires, but I would buy some colored electrical tape to indicate which is which once you check (Carefully!)

White is neutral, Black is Hot, Green or Unshielded is Ground. Sometimes there are Red, which are usually Hot.

Remember when dealing with a switched fixture to make sure you are switching the Hot line, not the neutral.

Answer 5

Older houses used one color because that was what was available back then. You can use a circuit tester to see which wires are which.