GFCI trips during rain

[Carl Morgan]

I'm curious as to why my GFCI is tripping when it rains. It doesn't happen
during brief showers, but if the rain is for a few hours or more, the outlet
will shut off. At least that is the way it happened the two times I was home
when it happened.

Could this have anything to do with a computer and UPS that I have plugged
into another outlet that is on the same circuit as the GFCI? It hasn't
rained since the last time it happened, so I haven't had the chance to move
the computer onto another circuit to see what happens.

Thanks for any ideas!

 

[NSM]

| I'm curious as to why my GFCI is tripping when it rains. It doesn't happen
| during brief showers, but if the rain is for a few hours or more, the
outlet
| will shut off. At least that is the way it happened the two times I was
home
| when it happened.
|
| Could this have anything to do with a computer and UPS that I have plugged
| into another outlet that is on the same circuit as the GFCI? It hasn't
| rained since the last time it happened, so I haven't had the chance to
move
| the computer onto another circuit to see what happens.

In a similar case I found a nail driven through the cable which leaked
current when it rained. That's what to look for. Isolate the cable and check
the insulation when it is soaking. Use a Megger if you have one.

NM

 

[James Sweet]

I'm curious as to why my GFCI is tripping when it rains. It doesn't happen
during brief showers, but if the rain is for a few hours or more, the outlet
will shut off. At least that is the way it happened the two times I was home
when it happened.

Could this have anything to do with a computer and UPS that I have plugged
into another outlet that is on the same circuit as the GFCI? It hasn't
rained since the last time it happened, so I haven't had the chance to move
the computer onto another circuit to see what happens.

Thanks for any ideas!

Many indoor GFCI outlets also control other outlets further down the chain,
including any that are outside. Check to see if you have a cover missing on
an outdoor outlet, or a broken downspout dripping on it.

 

[CJT]

I'm curious as to why my GFCI is tripping when it rains. It doesn't happen
during brief showers, but if the rain is for a few hours or more, the outlet
will shut off. At least that is the way it happened the two times I was home
when it happened.

Could this have anything to do with a computer and UPS that I have plugged
into another outlet that is on the same circuit as the GFCI? It hasn't
rained since the last time it happened, so I haven't had the chance to move
the computer onto another circuit to see what happens.

Thanks for any ideas!

Got any buried cables?

 

[Charles Schuler]

Many indoor GFCI outlets also control other outlets further down the
chain,
including any that are outside. Check to see if you have a cover missing
on
an outdoor outlet, or a broken downspout dripping on it.

Good advice. They trip around 5 mA so water in an outlet box will do it!

 

[Andre]

I once had this happen due to a damaged cable outdoors between my shed
and the main house. Seems that at 2am, the dew would form and cause a
trip, yet by about 8am it had dried up enough to not trip.

Took me a while to trace the beast, eventually got an electrician in
who (helpfully) found it in about 10 minutes.

-A

 

[mike]

I once had this happen due to a damaged cable outdoors between my shed
and the main house. Seems that at 2am, the dew would form and cause a
trip, yet by about 8am it had dried up enough to not trip.

Took me a while to trace the beast, eventually got an electrician in
who (helpfully) found it in about 10 minutes.

-A

I can't add to the advice except to say that you MUST fix it.
The GFI trips cause you have a path to ground. But you may also
have a much better path between hot and neutral that can cause a fire
WITHOUT tripping the GFI.

Speaking as someone who's been burned to the ground twice, "FIX IT."
And I don't mean. "fix it tomorrow."
mike

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[Aldo Larrabiata]

Check everything, connected to the line supplied by this GFI, which could be
exposed to rain or moisture. Either directly (outdoors) or indirectly
(indoors), by streaming or filling !!
Some years ago, I was living in a residence where the corridors were placed
outside the buildings. The ceiling lights mounted below the upper corridor
were filling by the water flowing through the mains ductings !
I just dismounted two of them and everything recovered when dry !
Dunno where was the water entrance located. The electrician guy fixed it.

By the way should you have 5 mA or even 10 mA diff protection, they're very
sensitive and very low tolerant.
If the head diff opens you're potentially in danger because of its tripping
current of 600 mA or more. That's enough to kill a T-Rex !