Breaker trips when turning on light switch

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Old 11-16-16, 01:59 PM
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Breaker trips when turning on light switch

Suddenly, every time I flip on the wall switch to my porch lights, the corresponding breaker switches off. As long as I leave that one particular wall switch off, the breaker can be reset and stays on for all other wall outlets. I thought the problem must be the toggle switch for the porch light, so I replaced it with a new switch. The problem remains the same. Any suggestions are appreciated.
 
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Old 11-16-16, 02:21 PM
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Welcome to the forums.

It's very rare for a switch to go bad and even more for it to cause a short.

Does that switch that causes the breaker to trip directly control lights or receptacles ?
You'll need to disconnect things or remove bulbs to locate the short.
 
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Old 11-16-16, 02:54 PM
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The hot wire going from the switch to the porch light is the problem. It is being shorted to a neutral wire or a ground wire. If there has not been any construction (nails being attached to the walls inside or outside) in the area between the switch and porch light, I suspect the problem is in the porch light electrical box.
Remove the bulb and reset breaker with the switch off. Turn switch on. If breaker does not trip, short was being caused by bulb. Replace bulb. If breaker trips, remove bulb socket from electrical box and remove the hot or neutral wire from the socket. Reset breaker with switch off. Turn switch on. If breaker doesn't trip, replace the bulb socket. If breaker trips, you need to install a new romex cable from the switch to the electrical box as the old cable is shorted somewhere inside the wall. Hope this helps.
 
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Old 11-16-16, 08:19 PM
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Is it an Arc Fault Breaker? Does it have a test button on it?
 
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Old 11-17-16, 01:32 PM
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Thanks. I will give this a try tomorrow when I can be home in the daylight. I hope I don't need to know this, but what is a romex cable? Are you saying I might need to run it from the switch to the breaker box or to the bulb socket?
 
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Old 11-17-16, 01:39 PM
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Thanks. No construction anywhere nearby for more than a year (when the porch lights were installed). I'll try you recommendation. Thank you! So, a bad bulb can actually cause this problem? I hope that's all it is.
 
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Old 11-18-16, 05:38 AM
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Thanks.

The switch controls the two porch lights
 
  #8  
Old 11-18-16, 06:41 AM
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romex cable
More correctly called non metallic cable (NM or NM-b) it is two or more wires in a non metallic sheath that is the most common method of wiring in modern construction. In Houston almost any house built in the '50s or later will use it.

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  #9  
Old 11-20-16, 01:45 PM
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Odds are something in one of the porch lights has rotted out. You will have to open them up and have a look.

You might need a new cable, but that is really unlikely. They don't just go bad unless damaged by nail or something.
 
 

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