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I am installing a ceiling light fixture. I was expecting to see black, white, and green wires. Can someone please help identify what each wire is for?

Since a couple of people have asked to see a picture of both the included instructions as well as the light fixture itself, here they are.

instructions

light fixture

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    The information you want is at the other ends of the wires from the ends in the photograph. - How many bulbs are in the fixture? - Do you have a means to test continuity? – A. I. Breveleri Nov 12 '16 at 21:20
  • Two bulbs. Not sure how to test continuity. – Steve Barden Nov 12 '16 at 23:48
  • What do the instructions say? – Tester101 Nov 13 '16 at 2:09
  • It's just a diagram with no words. Totally useless. – Steve Barden Nov 13 '16 at 2:51
  • I have posted pictures of both the instructions and the fixture below. – Steve Barden Nov 13 '16 at 16:01
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"L" for load. Green is an earth, white wite with striped symbol will be another earth and the unmarked will be your neutral or return. Continuity tester would be the safest option. Load wire should go to the tips in the lamp holder and neutral should go to threaded/screwed section of lamp holder.

  • I agree. This is what I would guess if the NEC had a section on guessing. - The bit of insulation left on usually indicates the ground, and the L often indicates the hot. It's just that I don't trust CAL not to get it completely bass-ackwards. – A. I. Breveleri Nov 13 '16 at 23:36
  • In this case "L" would stand for line, not load. It would be line, neutral and ground. – Speedy Petey Nov 13 '16 at 23:57
  • @speedy petey Potentially. But I would say Load as it's after the switch or any other control on the circuit - from what I can see. – Joshyp00 Nov 14 '16 at 0:20
  • After testing with a continuity tester I discovered: 1) the "L" wire is connected to the threaded part of the light; 2) the plain wire is connected to the middle part (where the very bottom of the bulb touches); 3) I'm assuming the 3-line wire is for ground. So...which one is considered hot and which is neutral? – Steve Barden Nov 15 '16 at 22:22
  • It's bad practice to have the threaded section connected to your hot wire as this is what makes contact with the threaded section on the lamp. If a person were to change the lamp with the circuit still energised it could be possible to come into contact with the exposed live part. If it's a very cheap fitting, it would not be a great stretch of the imagination to think good practice was not employed during manufacture. – Joshyp00 Nov 15 '16 at 22:59
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You are correct, the instruction sheet is worse than useless. It doesn't even match the apearance of the product. Also, the lamp is very poorly designed. And I notice that its safety certification comes from el Cheapo knockoff Intertek instead of an established lab such as Underwriters. All this means that you can have the elegance of a $250.00 lamp for, like, $84.00, but you're gonna have to do a little work.

You can safely assume that the green wire is intended as a fault ground for the ceiling box cover plate (the part installed in step 4). This leaves the three wires in the transparent cord to be identified.

You have two sockets in the fixture. Each socket has a shell, the part with the screw threads, and a tip, the little strip at the bottom that contacts the metal dot in the center of the bulb base.

Very likely, one of the cord wires is connected to the metal casing of the fixture (the part with the threaded rod). This is the fault ground for the lower part of the lamp. One of the other wires is connected to both shells. The last wire is connected to both tips.

Your problem is that the three wires appear identical and are not clearly marked. You can't go by what is most likely; you'll need to determine which wire is connected to what. One of the wires has a bit of insulation left on, and is marked with a tape printed with lines. Another wire seems to have the letter L stuck onto it. But what does that mean? Without a diagram you can only guess. Frankly, given the quality exhibited so far, I wouldn't trust these signals even with an included diagram.

So you cannot use this fixture until you know which of the three cord wires are connected to the shells and which to the tips. You will need to learn how to measure continuity. You can buy a continuity tester at Wal-Mart for under $7.00.

You can verify that the continuity tester is working by touching the two probes together.

Simply hold one probe against a shell and try the three wire ends with the other probe. Only one wire will present continuity. This is the "shell" wire. Check that the other shell is also continuous with the shell wire.

Do the same thing with the tips to find the "tip" wire. Label the wires as you find them.

Connect one probe to the remaining wire and poke the metal fixture with the other probe until you get a continuity indication. This proves the fault ground wire.

Now, in step 3 on the diagram, connect the cord's fault ground wire and the green wire to the house fault ground; connect the shell wire to the house neutral; and connect the tip wire to the house switched hot.

If you are in the U.S.A. and your house wiring is not ancient, the fault ground will be bare, green, or green+yellow. The house neutral will be white, and the switched hot is never white and usually black or red.

  • This is very helpful. I've ordered a continuity tester and will be able to have answer in a few days. – Steve Barden Nov 14 '16 at 4:35
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Notice that both the green wire and one of the transparent wire have a tag that looks like three lines? That is what is referred to as "Grounded." The neutral wire can be grounded but the ground cannot be neutral. That means the transparent wire with 3 lines is "white"(neutral) and the green is still just the ground.

This leaves us with two wires. Normally these last two wires would be red and black. the L is referring to the "Line," or the red wire(switch leg), connect this to one side of the switch(terminal screw), then connect the remaining wire(black) to the other side of the same switch(terminal screw)." The purpose of the neutral wire is for a power return path. The purpose of the green wire is safety. The purpose of the black wire is to maintain electricity. The purpose of the red wire is literally the switch or "gatekeeper".

  • Red Wire: L tag
  • White Wire: 3 lines on tag (same tag on the green wire as well)
  • Black Wire: Hot circuit wire
  • Green Wire: Ground for the light fixure

    Explanation of 3 line symbol that is on two of the wires:

Explanation of 3 line symbol that is on two of the wires

Diagram of a lightswitch circuit:

Diagram of a lightswitch circuit

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