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View Full Version : Why unrelated circuit breakers poping -lightening?



Barry White
05-31-2011, 07:53 AM
Three circuit breakers on my 8 month old 200 amp service activated during a heavy thunder, rain and lightening storm this weekend ...


1. An external GFCI outlet with an extenison cord fried because my brother in law left the downstream end lying in the grass.

2. A second but internal GFCI breaker interrupted its circuit - its on its own and a different circuit, of course, from the outside GFCI. Only thing fed by this circut is a small power bar/interior extension cord - there were no appliances or lights on at the time of the storm. It reset with no problem.

3. A separte 15 amp double pole breaker shut off in the main panel - it supports small appliances: small frig, clock radio and a couple of lights - these were on at the time. It also reset with no problem.

Obvioulsy the extension court in a heavy rain would short the one GFCI but why would it fry the thing. And why would a second unrelated GFCI and a 15 amp breaker decide to interrrupt, too.

Can a lightening storm do this?

Bruce King
05-31-2011, 10:47 AM
Three circuit breakers on my 8 month old 200 amp service activated during a heavy thunder, rain and lightening storm this weekend ...


1. An external GFCI outlet with an extenison cord fried because my brother in law left the downstream end lying in the grass.

2. A second but internal GFCI breaker interrupted its circuit - its on its own and a different circuit, of course, from the outside GFCI. Only thing fed by this circut is a small power bar/interior extension cord - there were no appliances or lights on at the time of the storm. It reset with no problem.

3. A separte 15 amp double pole breaker shut off in the main panel - it supports small appliances: small frig, clock radio and a couple of lights - these were on at the time. It also reset with no problem.

Obvioulsy the extension court in a heavy rain would short the one GFCI but why would it fry the thing. And why would a second unrelated GFCI and a 15 amp breaker decide to interrrupt, too.

Can a lightening storm do this?



Yes, very common.
Breakers can trip with nothing more than a large magnetic field present.
Many breakers are tripped when you purchase them. This does not mean they were really checked for exact current tripping but just that they were sent through a magnetic field large enough to check the mechanical trip mechanism.

I would add another ground rod about ten feet from the existing one in the direction away from the house.

Barry White
06-01-2011, 09:42 AM
Thank you, Mr King, its a relief to know this; I had images of somthing serious. We will add the second ground rod as per your advise.

BW