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In order to keep a hanging pendant light from falling through the cover plate in the ceiling I tied a knot in the electric wire, as a stopper. Is this safe, or did I just create a fire hazard? If it's unsafe, what can I use as a stopper on the electrical wire of a pendant light?

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  • I've seen hard plastic wire holders that allow you to create a short loop without actually making a knot on the wire itself. I don't know what they are called (and certainly not in English), but any decent home improvement or home electrical store should have them or know what they are called so you can look online. The cost should be trivial since it's basically just a piece of plastic.
    – user
    Jan 7, 2013 at 9:30
  • @MichaelKjörling I can't find something like this anywhere. If anyone knows of one, please tell me about it
    – David
    Jan 7, 2013 at 13:55
  • @MichaelKjörling try "zip ties"
    – ratchet freak
    Jan 8, 2013 at 0:07
  • @ratchetfreak Actually, that's not what I have in mind, although it should work as well. I've looked but was unable to find a picture; sorry.
    – user
    Jan 8, 2013 at 9:00
  • zip ties didn't work. They didn't get tight enough and the wire could pull right through with minimal effort.
    – David
    Jan 8, 2013 at 12:23

2 Answers 2

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In the case that the lamp is light weight enough to not stress the cord, there's a specific knot for that called an Underwriter's Knot that is supposed to put minimum stress on the conductors and provide enough bulge to keep it from pulling out. Since most PVC insulation will cold flow under pressure, the edges it butts up against must be well rounded.

Underwriter's Knot

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  • Isn't this actually supposed to be a temporary measure? The OP seems to be asking for a more long-term solution...
    – Pacerier
    Dec 18, 2013 at 6:06
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    The Underwriter's Knot is intended for permanent use to form a strain relief so the wire end connections do not get pulled apart in the lamp socket or out of the plug as it guarantees slack in the tails. Given a couple replacement plugs I've dealt with, it's a really good idea to use it as the clampy-do on most replacement plugs allows the cord to slowly slip out as it's yanked on as the method of removal by your warehouse shop-vac operator. Your first indication something's wrong is to examine the plastic body for melting due to the wire slowly coming loose where the screw holds it down.
    – Fiasco Labs
    Dec 18, 2013 at 6:31
  • Knots in power supply cords are used everywhere, and have been since the beginning of home electrical use. Lampholders, tools, appliances, you name it. There are alternatives sometimes used, but none of 'em are as cheap as a knot.
    – kreemoweet
    Dec 21, 2022 at 3:01
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It's not perfectly safe, but it's a good temporary solution.

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    Why isn't it safe, and what is a permanent solution? Thanks
    – David
    Jan 7, 2013 at 0:50
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    If the wire is under tension, over time the insulation will wear, creating a hazard.
    – Jason
    Jan 7, 2013 at 1:46
  • There are suspended lights that use the electrical cable as the suspension element. It is specially made so that the wires don't take the weight. Not a very good idea if its common lamp zip cord.
    – Fiasco Labs
    Jan 7, 2013 at 2:24
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    @FiascoLabs there are (cheap) lightweight pendant lamps that are designed to hang from the electrical cable. They usually have a compression fitting to prevent the wires from being pulled through.
    – Brad Gilbert
    Jan 7, 2013 at 12:57
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    The compression gadgets are called CGB's cord grip bushings. A UL listing on a light fixture over rides the NEC and many pendant lights are suspended by the cord. The NEC is for the structure wiring. Any one that sold a non listed device is taking a chance in the U.S. even if 100% listed parts are used.
    – Ed Beal
    Aug 23, 2018 at 15:23

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