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I had an electrician install two hanging pendants over a kitchen island. The install went well and the pendants work fine.

However, after the install I've had an opportunity to look at the fixtures up close, I can't understand what this wire is. The light fixture hangs with a chain and has a typical-sized black cord which I assume is the main power for the pendant. However, there's a copper-colored wire which hangs along down with the chain and the black cord, which doesn't seem normal to me.

Any idea on what this is? I'd like to remove it, but I want to be sure what it is and if it's important first.

Here is a closeup of the copper-colored wire: The mysterious copper-colored wire closeup

And here is a view of the full pendant:

The hanging pendant with a copper wire intertwined with the chain and cord

  • 3
    Give it some time, bare copped will darken by itself over time. Ever seen those matte black overhead wires trams and electric trains use? They were as shiny as your one when installed. (unless it's painted with clear paint) – Agent_L Jul 28 '16 at 12:31
22

I'm almost certain it is the ground wire. Do not remove it.

If you were to open the light fixture, there should be a screw where one end of the ground wire is attached. Then, mounted in the ceiling is a metal box through which is fed all the electrical wiring. There's a screw on the ceiling box that the other end of the ground wire is attached.

enter image description here

Thank you. A natural follow-up question to this, since the original intent was to remove the distracting copper wire for aesthetic reasons, is: will the ground wire be less effective if it is painted or somehow covered to match the rest of the fixture?

Adding paint is essentially adding a layer of insulation to the wire. Since insulated wire still conducts electricity, a painted ground wire will be just as effective (i.e., conductive) as one that lacks an exterior coat of paint. You simply want to ensure that you do not paint over the location where it is attached to the screw on both ends (it needs metal-on-metal contact).

  • 2
    Is there a reason the fixture would have been built like this instead of using a three-conductor cord? – Random832 Jul 28 '16 at 5:04
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    It's probably easier to buy a piece of black 3-wire cable and replace both the ground wire and the 2-wire cable than to remove the ground wire, paint it and reinsert it. – Simon Richter Jul 28 '16 at 12:29
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    I think it was added by the electrician who installed it in order to make an old/imported fixture conform to new/local code. – Agent_L Jul 28 '16 at 12:30
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    @Agent_L No, this arrangement is standard for lamps in the US. Historically, lamp cords contained only two conductors (power and neutral) that went to each lamp socket. When something goes wrong and the power touches the (commonly metal) lamp fixture, people get hurt. Starting in the (someone help here with the decade)'s ground wires were added to ground the fixtures, but the same lamp socket arrangement was kept. Many/most fixture makers never moved past this "temporary" workaround. Perhaps someone else can give background as to why. – JS. Jul 28 '16 at 17:46
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    I wouldn't recommend removing or changing the wire. It was designed to fit that fixture, the UL labs tested it, it should be safe far that fixture. Rewiring it could potentially make it a fire hazard, the fixture might be bonded at multiple location along the wire and if missed could become a fire or electrocution hazard. – RomaH Jul 28 '16 at 18:00
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Yes it is a ground wire. It is required by more-recent codes.

They definitely can be unsightly. Instead of trying to paint it, which will look awful, just replace it. Some black-insulated, copper, 16 or 14 (or maybe even 18) AWG wire should do the trick quickly and easily. There's no need to disturb the other wires, just run the new black wire in the place of the existing bare copper wire.

  • 4
    If you want to spend the time you can re-wire the entire lamp so it uses one wire for all 3 contact. Make sure you get the hot-neutral-ground correct though, because it can have safely implications if you swap hot/neutral. – Nelson Jul 28 '16 at 9:15
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    I WOULD NOT try to replace this ground wire. It is likely to be riveted in place, or connected to a large ring terminal, which will not be easy to replace or duplicate. .......Just leave it. – Speedy Petey Jul 28 '16 at 21:27
1

It is a frame ground. It's bonded to the metal of the fixture so that if a bare live wire touches the metal it trips the breaker. If it wasn't there and a live wire was touching, nothing would happen; until you went to change or clean the fixture. Then you become the source to ground and will get a zap.

A frame ground is a safety requirement and is not to be removed. After a week you won't even notice it anymore.

-1

This is a ground wire. And it looks like the ground was added later or like only the cage is grounded.

Remove it only if you are replacing the 2-wire cord with at least 3-wire cord.

With 4-wire cord you can light the bulbs independently (power1, power2, (shared) neutral, ground).

Also be sure that all metal parts are grounded.

  • 1
    This ground was not added later. Almost every chain hung fixture comes like this nowadays. Also, the term "common" is not really an accurate or accepted term. The term "neutral" is the industry standard. – Speedy Petey Jul 28 '16 at 21:26
  • @SpeedyPetey: Surely there must be some adjective that clarifies the neutral is shared between the two powers rather than just calling it neutral? Or at the very least isn't this a reasonable use of the term? Even if not a technical electrical term I'd have thought it was meaningful (and indeed I worked out what it meant). – Chris Jul 29 '16 at 0:04
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    Honestly, I have no idea what the comment means. One of the reasons the term is not used for a neutral is that the term "common" is used in 3-way switching setups, so it can be confusing. This does not change the fact that it is incorrectly used by lay folks pretty regularly. – Speedy Petey Jul 29 '16 at 0:07
  • @Chris: Neutral and common are not the same thing. "Neutral" implies a balance (or lack) of voltage potential; "common" does not. Not all circuits use or have a neutral, but what about a "common"? It's not as subtle as the difference between groundED conductor and groundING conductor. – Jovet Jul 29 '16 at 4:58
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    Ah. I appreciate that neutral and common are not interchangeable but the original wording of "common neutral" suggested to me a neutral that was shared by both. It sounds like common has a technical definition that I was not aware of though that was causing the amibuity/confusion/whatever (I'm a lay folk - guilty as charged!) :) – Chris Jul 29 '16 at 9:33

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