wire burns up one inch before socket connector

[ledzephar1]

I have a Hampton Bay light hanging light fixture in my dining room that has been installed for about 2 years. One night while the fixture was on, we heard a pop and the light went out. Thinking it was just a bulb, I replaced it and light never came on. took fixture apart and discovered one of the wires was burnt about an inch before the connection to the porcelan light socket. Replaced the wire and light still did not work. I then replaced the dimmer switch which also burnt out. After replacing the dimmer, light worked for about a half-hour before the wire burned again. Rpleaced the wire for third time and reduced wattage of the light bulb from 100 watts to 75 watts - same problem. help!

[BobK207]

Bad socket? Too much internal resistance?

cheers Bob

[Goedjn]

Get a voltmeter, and check the voltage on that branch. Sounds to me like you're getting overvoltage, and the circuts going to keep burning out at the weakest point until you fix it.

[avid_hiker]

1) Make sure your light socket is not cracked or corroded, if so replace the socket. 2) Your lamp, from what I get from your post, sounds as if it is getting too hot and melting the wiring, which then shorted out and melted the switch. Not sure what this light looks like , so picturing it and your problem is yet possible......would you have a model# of this lamp or a location of a picture of the same model? You mentioned it was hanging, so Im figuring that the wiring by the socket of problem is not next to the ceiling but maybe 2 feet below?...is this correct? This matters...for concerning insulation above fixture which protects the wiring from overheating in incandescant ceiling fixtures. 3)You should probably make sure the breaker is working properly also. This will not cause the problem but should avoid major current issues. It sounds as if your breaker should have definetly tripped when this happened. 4) Replace the fixture......they are not all that expensive.

[Bob F]

I would guess that there is a partial short in the socket. Either that or the wire was REALLY defective. What happens if you fix it, screw in a dead light bulb, and tirn it on?

Bob

[Jeff Wisnia]

C'mon, you can't be serious...

If he had a serious overvoltage problem the bulbs would have been burning out regularly, long before any reasonable fixture wiring would overheat.

Jeff

[ledzephar1]

Thanks so much for the replies and ideas.

To reply to some of your questions: Can't find the model # but you are right in your assumption that the socket in the fixture is about 2 feet from the ceiling box. The fixture hangs from a chain which is about 2 feet long. I'm not sure if I mentioned it but I did replace the socket also. What really bothers me is this light was okay for 2 years before this problem occured and I have not made any changes in my circuits.

Overvoltage was one thing to check for. I will try to get a meter to check that but what would cause an overvoltage condition?

Thanks agan.

[scott21230]

Use a compact flourescent bulb instead of an incandescent. I think anything above 60W is probably above what it's rated.

[Goedjn]

Nope, on second thought, I agree with Mr. Wisnia.

I'd just keyed on device failure in two separate places, and that triggered the "check the supplied power" reflex. In retrospect, dimmer switches are the sheep of electrical components, (they spend their short, miserable lives looking for a way to die) so it's not unlikely that it was the death of the light that killed the dimmer, not the same thing killing both directly.

Does this device have more than two wires in it? maybe a fan motor that's stalled?

In the absence of that, I think I'd replace all the wires and the little cartridge thing that the light-bulb screws into. Those are only a couple of bucks.

--Goedjn

[hallerb]

bad socket high resistance causes heating and wire burn up near socket. replace socket and enough wire till your back to wire that hasnt overheated.

i fix machines that use heaters for a living its a very common failure. i carry a roll of wire for splicing cause it happens so much

[buffalobill]

[Chris Lewis]

According to Goedjn :

What it sounds like to me is that there's something wrong inside the fixture - eg: a bare spot on a wire, and when the fixture begins to heat up, thermal flexing is causing it to dead short. It's a little odd that it seems to repeatedly damaging the wire at the box, rather than something else, but dead shorts will certainly kill dimmers.

This is a chain-supported lamp? Check over the wire down the chain _very carefully_ - check for chafing and other scorch marks. Inspect all of the wiring inside the fixture you can get at.

[DIMwit]

Several years ago I had the same problem with a HD Hampton bay fixture and I corresponded with UL Labs on it and sent them photos of the porcelain sockets and the burnt wires.. The bulbs I had installed never exceeded the wattage rating on the fixture per socket or total. UL seemed indifferent. I guess Home Depot would have given me new lamp sockets if I pushed it, but I never did.

Bring it back to HD and ask them "this is UL listed?"

[hallerb]

UL seemed indifferent. I

I conacted UL once on a real safety hazard, they gave me the brush off and the unit involved I fix for a living.....

[ledzephar1]

Hi Chris. Yes, it is a chain supported lamp. I replaced the wire and the socket. I went to Home Depot and they still sell the same fixture. According to the specs on the box, the fixture is rated up to 100 watts. That is what I originally put in when I installed the fixture. Everything was fine for 2 years before this problem surfaced. No changes were made to the circuits feeding it. Would putting some shrink tubing in the place where it usually burns out help insulate it enough if the root cause is an external thermal issue? I am really baffled at this point. Thanks, Harry

[Bob F]

Unless the shrink tubing avoids a short from happening, it is not going to help solve this problem. If a wire burns out anywhere but at the connector end, the problem is probably related to too much current flow.

You could put an ammeter in series with the lamp and see whether it is drawing more than it should.

Bob