So the other night, the kitchen lights went out. Upon inspection, the bulbs weren’t burnt out, and replacing them did nothing. Lights still wouldn’t work.
As such, last night, I checked the breaker. No problems - not tripped. I crawled into the attic and checked the fixture’s wiring - nothing wrong there. I then climbed the ladder, took out the bulbs, and unscrewed the whole fixture. Every wire was connected and solid.
However, the individual wires leading to the three bulb sockets were twisted quite tight; a result, I suspect, of years of screwing in different light bulbs. When I loosened the sockets from the fixture, each spun around a few times until the wires untwisted themselves. When I replaced the fixture and put in the (original, unburnt) bulbs, the whole thing worked again.
I have absolutely no idea why the lights stopped working. Every connection was solid, and the bulbs fine. Could the individual twisting have resulted in a “pinched straw” as it were? I find this hard to consider, as connections by necessity have to be twisted to ensure conductivity. But this is the only change to the entire fixture I made.
Get an electrician to replace those wires ASAP. I suspect what has happened is that all the twisting pulled/bent/strained the wires hard enough to break the conductors inside the insulation somewhere; when you untwisted them, you allowed enough slack for the conductors to contact again. This is a bad situation, since you now have the possibility of high-resistance contact point, which can cause significant heating and could lead to an electrical fire. I would not use those lights until the problem has been resolved.
You’ll need someone with experience to figure out if you have broken wires (that you can’t visually locate) or if there is another problem. Often times fixtures will develop an open neutral and finding it becomes the challenge.
The metal conductor inside an insulated wire is stiffer and less stretchable than the plastic around it. You may have a broken conductor inside the insulation, caused by all that twisting. The plastic holds it in approximately the right spot, and when you relax the twisting the ends of the conductor can meet one another again and conduct electricity.
The problem is, the spot where they meet is not a good connection. It can open up again, so your light goes off. Worse, it could become partly disconnected, with an arc passing current between the two pieces, and a voltage across it. This means there is energy being consumed at that tiny little hidden spot, energy that could start a fire or do other evil.
So, yes, what they said.
I think it is much much safer to leave the breaker off, or to take the bulb out of the fixture. In this case you should not be able to pass any current through a faulty contact inside the insulation, so no energy doing evil. However, we are still, of course, to some degree guessing what is going on. If there is a break in the insulation or a stray strand of wire lying across something, all bets are off, so to speak. So, leave everything as disconnected as you practically can. If you have to leave that breaker on (maybe Aunt Bessy’s iron lung is hardwired to the same circuit), at least, open things up again and visually inspect for short circuits, and then leave the fixture turned off and the bulb out.
An open neutral is where you loose the return path to ground. Since you can trace out an open hot wire by using a voltage sensing device, and not an open neutral in the same manner, they are harder to locate. An open neutral is simply a break in the grounded conductor (some people call it the negative wire or return conductor, it’s usually white in an AC circuit) and is a bitch to locate and can cause weird problems like dimming lights, or intermittent power. They’re also not usually safe to have around the house.
I suppose this may be obvious, but if other people use your house, it may be an idea to stick some duct tape or something over the switches. It’s too easy to flip a switch out of habit without thinking.
Just me and my wife. But I was going to put tape over it regardless, as I tried to turn it on yesterday, even though I knew it wasn’t going to work. Flip switch first, ask questions second…
Actually I just found one of these a few weeks ago. I just grounded the hot wire at the box and supplied power to the open neutral through a low watt light bulb from another circuit and just found where the voltage sensor quit beeping.
It turned out to be a staple I had put in badly. :smack:
Inside a newly plastered and painted wall :smack: :smack:
A whole day wasted finding it and fixing it. :smack: :smack: :smack:
>Ah. Gotcha. Wire = Sheathing + conductor. I’ve always mentally called the conductor “wire,” as well as the whole. Now I know.
I didn’t mean quite that much. Insulation + conductor = insulated wire. Whether somebody who says “wire” means the conductor, or the insulation and conductor together, or several insulated conductors bundled together inside a sheath, is I think not necessarily clear except from the context. That’s why I said "The metal conductor inside an insulated wire ". And I never did clearly say that, because the conductor is stiffer and less stretchable than the surrounding plastic insulation, it may very well break before the insulation does, which is how breaks get hidden inside whole insulation.
>An open neutral is where you loose the return path to ground.
Right. Though I think this detail can be confusing, because it better reflects what purpose the wires serve to say you lose the return path back to the common neutral connection (which is also ground). Normally, a circuit breaker panel and distribution center has a chassis that is grounded to a ground rod in the earth, or the steel frame of a building, or a heavy water pipe, or these sorts of things. There are also generally heavy, uninsulated terminal blocks made of a single block of Aluminum mounted on this chassis. All these things are, clearly, connections to ground. Then, you run your hot/neutral/ground sheathed bundles of wire around to outlets and such. In the circuit breaker panel, the white neutral wires and the bare ground wires of these bundles are connected to the ground connections. So, the ground wires and neutral wires wind up at the same place. It’s their PURPOSE that is different, not what they’re connected to. Whatever current you draw through the hot wire is supposed to complete its circuit through the neutral wire. The ground wire is there to provide a safe alternate path if something goes wrong - like, f’rinstance, an open neutral and a short to the chassis of an appliance or lamp. So, I think it might be more consistent with the neutral wire’s purpose to say an open neutral is a broken connection somewhere along the neutral wire path back to the circuit breaker panel. One last note on this - sometimes you do something different with the neutrals back at the panel, like run them through special transformers with the hots to measure “ground fault” currents that seem to be going someplace they don’t belong and trip a “ground fault interrupter”.