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Flip the switch and breaker trips, cause is?

Posted by stash-hdy (My Page) on
Sun, Nov 2, 08 at 9:31

When the attic light switch is flipped to on, the breaker trips. Under this condition is it correct to assume that the problem lies at the swich or between the switch and the light. In the switch off position the circuit if fine.


Follow-Up Postings:

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RE: Flip the switch and breaker trips, cause is?

The short to ground could be anywhere in the circuit. As soon as you close the switch, unlimited current is flowing in the circuit. The only place unlimited current can flow to is to neutral/ground. The unlimited current trips the breaker. The problem is most likely at the switch or light. However, a nail through the cable at any point or a rodent chewing through the cable jacket could also cause this problem.


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RE: Flip the switch and breaker trips, cause is?

How would you find the short to ground if its not in the attic switch circuit? Not knowing the wiring within the walls? Could it be in a plug on the opposite wall, would they have ran the light from a plug? The breaker is labeled kitchen lights, if I flip the breaker, find all the lights and plugs on the circuit and check each?? Help

If it's a nail does the wire need to be replaced?


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RE: Flip the switch and breaker trips, cause is?

Usually in a case like yours with a dead short, a wire has come loose at a switch or device and is shorting out the hot wire. I'd start troubleshooting by visually checking all wires at every switch and device in the circuit controlled by the breaker (kitchen lights) which is tripping. Make sure the wires are connected to where they are supposed to be. If no one has been doing any remodelling or picture hanging then there isn't much reason to suspect a nail or screw has suddenly punctured a wire. Also check any GFCI receptacles on the circuit for malfunction. If you have a nail or screw puncture, which is unlikely, you can replace the cable around the fault by using junction boxes for the splice.


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RE: Flip the switch and breaker trips, cause is?

How would a nail find a wire? Did you go around nailing things to the walls?

Shorts are RARELY along the wiring within the walls. Usually they are at a box or other outlet.

How did this come about? Did it just start happening? Were you messing around with anything?
Details, we need details!


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RE: Flip the switch and breaker trips, cause is?

The OP never stated that he/she was nailing anything to the walls. I stated that it was very unlikely for this to happen. I suggested that the OP check every switch and device for correct wiring with no shorts to neutral/ground.


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RE: Flip the switch and breaker trips, cause is?

Agree with petey, unless you have been nailing something to the wall or ceiling, nails are not likely to be involved. I have experienced HOT NAILS. They went thru one wire and did not cause any breaker poppage. When you touched the nail it was quite a thrill though.

I would start by taking the switch plate off, (NOT the switch) and with a handy flashlight inspect for any wire touching the side of the box or other wires. Then if you seen nothing out of the ordinary replace the plate and flip the switch or manually flip the breaker. Is the light just a light or is it a ceiling fan? Fans can vibrate connections loose and cause this problem. If you know how, remove the cover and look in the ceiling box, With the info you have given you should find the problem in one of these two places. If this is getting into unfamiliar territory for you, CALL AN ELECTRICIAN, , it's not worth the shocks you could receive, just to save a few bucks!!


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RE: Flip the switch and breaker trips, cause is?

When the attic light switch is flipped to on, the breaker trips. Under this condition is it correct to assume that the problem lies at the swich or between the switch and the light. In the switch off position the circuit if fine.

The problem will be at the switch or the light, or to a lesser possibility in the wire between. There should be no need to check all the devices on the circuit.


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RE: Flip the switch and breaker trips, cause is?

Sorry BB, I thought I read that the OP suggested that. My fault for reading too fast.


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RE: Flip the switch and breaker trips, cause is?

A case like this is usually the result of a switch loop being mis wired. You are actually turning the switch on when the breaker trips.
Did you do any changes to the wiring at the light? Did you decide it was mis wired because all the colours didn't match?


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RE: Flip the switch and breaker trips, cause is?

The problem was the wire, switch and light OK. It was not worked on since the house was built, something shorted out the wire. I could not get the original wire out of the wall, clipped the ends and left it. Thanks for the help in resolving the problem.


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