# Lights suddenly tripping breaker



## AllanJ (Nov 24, 2007)

Somehow two wires touched or the insulation wore through where a wire rubbed against some metal object that should not have happened. You will have to find where that happened, maybe at the light switch, maybe up in one of the light fixtures. In the latter case one of the lamp sockets might have developed a short circuit.

Try removing the light bulbs (lamps), first all of them then put one back at a time to see if the breaker trips for one light location. Don't touch the glass bulb with your hands or fingers, if you do accidentally, wipe it with alcohol before turning it on again.


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## MontyP (Oct 23, 2011)

Thanks for the prompt response Allan.

I wondered about the receptacle as that is the only thing that "changed" when I plugged the new TV in (even though I never moved the receptacle. However, if the short was in the receptacle why is it only the ceiling lights that switch the breaker when switched on? Everything else in the room (e.g. TV, clock radios, ceiling fan, table lamps) works fine.


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## MontyP (Oct 23, 2011)

Thanks again Allan. I am going to go and try removing all of the lightbulbs and replacing them one at a time. I assume I should put each one in and then try the switch and see if it trips the breaker. Would you remove each bulb again after testing it (assuming it doesn't trip the breaker) or leave them in until you find the one that trips the breaker.


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## MontyP (Oct 23, 2011)

I removed all four bulbs from the ceiling. However, as soon as I flipped the switch on the breaker tripped (with no bulbs in the ceiling).


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## Jim Port (Sep 21, 2007)

Perhaps the act of plugging in the TV caused two wires to touch that should not be touching.


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## MontyP (Oct 23, 2011)

Thanks Jim.

There was a tv plugged into the receptacle before as well as a cordless phone. I just bought a bigger TV. Now I have a power bar plugged into the receptacle and the TV and phone are plugged into it. 

Maybe unplugging the old tv and phone and plugging in the power bar moved the receptacle enought to have two wires touch. 

However, everything in the bedroom works (including the stuff plugged into the recpetacle) as long as I don't turn the ceiling lights on.

Is it possible that the lights are conneceted off the receptacle (i.e. the lights are the last item in the circuit) and the short is in the power going from the receptacle to the lights?


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## kbsparky (Sep 11, 2008)

MontyP said:


> I removed all four bulbs from the ceiling. However, as soon as I flipped the switch on the breaker tripped (with no bulbs in the ceiling).


Now LOOK into the sockets of those bulbs. Is one of them smoked, or shorted out?

The bottom tab should be clear of the screw shell, and not touching. I've seen bad sockets where the tab came loose, and rotated to the shell and shorted out.


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## jimmy21 (Jul 2, 2008)

there are many reasons for this. You have a short somewhere. A rat could have chewed through insulation. I have seen situations where silicone was used at the time of intallation and it took many years for the silicone to eat through the insulation. Somebody could have done a crappy installation to begin with and the wires were just barely not touching and now the wind blew on your house and the wires move just enough to now be touching. Bottom line is you have wires touching somewhere and your going to have to track it down. 

Im assuming the receptacles aren't switched with the lights? If they are not switched, then the receptacles have nothing to do with your problem. 

What you need to do is figure out how your lights are wired. Whether the wiring goes through a junction box or if it goes from the light switch to one light daisy chained to the other lights. If you can figure out how the lights are wired, you can start disconnecting things and figure out where the short is located


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## MontyP (Oct 23, 2011)

Thanks gents. 

It looks like there is a short somewhere. It is just a coincidence that the problem appeared at the same time I connected the new TV.

I think figuring out how the ceiling lights are wired and then trying to figure out where the short is located is probably beyond my limited abilities. Accordingly, I am going to call an electrician. 

I appreciate everyone's advice. 

Thanks again.


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## gregzoll (Dec 25, 2006)

The dead short is either going to be in a fixture or a junction point.


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## jimmy21 (Jul 2, 2008)

gregzoll said:


> The dead short is either going to be in a fixture or a junction point.


Did you see that in your glass ball? Very likely, but not 100%. It's definitely where I would start if they are accessible. There's no definitive reason for a short to suddenly show up.


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## gregzoll (Dec 25, 2006)

jimmy21 said:


> Did you see that in your glass ball? Very likely, but not 100%. It's definitely where I would start if they are accessible. There's no definitive reason for a short to suddenly show up.


No, I only had to read the first posting to know that there is a dead short caused by the plugging in the fixture. Does not take a crystal ball to see that.


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## jimmy21 (Jul 2, 2008)

gregzoll said:


> No, I only had to read the first posting to know that there is a dead short caused by the plugging in the fixture. Does not take a crystal ball to see that.


Plugging in a tv and unplugging it does not cause a short in an unrelated receptacle. Unless maybe its a switched receptacle. If no electrical work has been done recently then there is no telling where the short is. If electrical work has been done recently obviously that is where the short is going to be. At this point, a rat chewing into a cable sounds as likely as some conductors in a box moving themselves and beginning to touch


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## MontyP (Oct 23, 2011)

Thanks gents.

The receptacle is not switched and no wiring or other electrical work has been done since the house was built in 2001.

For my own edification what is a "dead short"?


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## jimmy21 (Jul 2, 2008)

MontyP said:


> Thanks gents.
> 
> The receptacle is not switched and no wiring or other electrical work has been done since the house was built in 2001.
> 
> For my own edification what is a "dead short"?


The same as a regular short with an extra word added in for emphasis. It may have some definition I don't know but it effectivly means the same thing. When current can make a complete circuit without going through any resisting load, aka, wires touching or something hooked up wrong



Ah, i guess they do have different definitions. A short circuit is just when current is able to go on an unintended path. This doesn't necessarily mean it is a 0 resistance path. This could be as simple as a small amount of current leaking to ground. A dead short is what we normally think of as a short. When there is a direct path back, with negligible resistance.


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## MontyP (Oct 23, 2011)

Hi All,

I just spoke to my wife. The electrician has come and gone. 

Apparently there were two wires touching in one of the light fixtures. It looks like some electrical tape had come off. The good news is there are no raccoons or squirrels in the roof chewing through my wiring and the builder had done everything properly (including having each fixture connected to its own box - a step apparently some omit). 

It appears to be pure coincidence that this came to light at almost the exact moment I hooked up the new TV. 

Thanks again to everyone for the advice. Much appreciated.


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## gregzoll (Dec 25, 2006)

Electrical tape should never be used. Any connections should have wirenuts holding them together.


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