Installing a ceiling light?

Question

I am instaling a ceiling light that has two wires, both of which are clear. The ceiling hole has four wires--black, white, red and green. How do these all match up?

Answer 1

The fixture should have a switch leg conductor and a grounded (Neutral) conductor. The neutral should be white or gray; the hot may be any color except white, gray, or green. If the fixture wire insulation does not comply with these rules, check to be sure that it has a "Listing Mark" on the fixture. (It should also have a grounding conductor; usually on lighting fixtures (the Code now calls them "luminaires") this is a bare copper wire. Again, if it does not have a grounding conductor, I doubt the product is "listed".

To view the acceptable listing agencies whose Mark is likely to appear on this fixture, go to the OSHA website and then do a search for "NRTL"s. You will end up with a list of around 20 independent testing labs that are certified to examine products and compare them to nationally recognized product Standards.

If your fixture is "Listed", my next question would be, "Did you disconnect all of the wires in the ceiling box when you removed the old fixture? If your house uses Type MC Cable (that is the only way I can think of to explain two ungrounded conductors - the black & the red, one grounded conductor - the white, and one grounding conductor - the green. Any other system would not use a green insulated grounding conductor), it could very well be that the contractor installed a "3-wire" cable assembly, but only needed two of the conductors. Check to see which conductor activates a current tester when the switch is closed. That is the conductor to use, probably along with the white insulated conductor.

It bothers me a great deal that you say there are only two conductors on the fixture. If that is truly the case, AND you find a Listing Mark on the fixture, install a GREEN grounding s***w in the metallic ceiling box. Then, install a grounding pig-tail to the ground s***w. Using a wire nut, secure the green conductor, and the loose end of the pigtail (green insulated or bare copper) to another grounding pig-tail. Using another grounding s***w (NOT A SHEET METAL s***w!!!!) to secure the grounding pig-tail to any part of the metal of the fixture (hopefully, inside of the fixture, covered by the trim).

Put a wire nut on the unused conductor and put it back into the box.

(This was the "medium" length answer – the short answer is follow NEC 90.1 (C), and hire a qualified Licensed Electrical Contractor so you don’t burn down the house.)

Answer 2

This is the way it should work if circuit is done correctly. I would get out volt meter and find out what is hot and what is not. But if wired correctly then Black is 120 volts, Red is 120 Volts, White is common, Green is ground. Should have two light switches on wall. One controls the Black wire and the other switch controls the red wire. They do this so you can hook up a ceiling fan with light and control both functions separately. Make sure switches are turned off. Make sure light fixture will accept voltage 120VAC.  Connect Black to Clear, Connect White to other Clear wire. Install wire nuts on all wires backup with electrical tape.  Be careful electricity is nothing to mess.

Answer 3

You haven't said where you are from, which will make it difficult for you to get a definate answer, because the colours aren't universal.

In AUSTRALIA, black is the neutral, red is permanent active, white is the switched active and green is earth (there should be one more red wire than black wires if this is the case) . You need to connect the black to one of the clear wires and the white to the other. You should also put a connector on the red wires, and if it is a metal light fitting, the green needs to be connected to the frame of the light fitting.