GFCI flips when there's lightning

[csdude55]

I'm having an issue at home that I don't quite understand. It's been happening since I bought the house about 16 years ago.

I have a GFCI receptacle in my kitchen, above the counter. Nothing is plugged in to that outlet, but it appears to be ran in parallel to another receptacle above the counter (that has a can opener and a water dispenser plugged in 24/7), and an outdoor receptacle that's about 1' above the deck floor but under the eave, and it has a waterproof cover.

When there's a storm in the area, every once in awhile there will be a big crack of thunder, a flash of lightning, then POW!! The GFCI flips off.

Since I can't duplicate the issue on demand, this has been tough to figure out. I don't see any way for water to be getting in the receptacle outside, but the fact that it only flips when there's hard lightning (even when it's not really raining) makes me think that maybe it's a power surge instead of water? Unless maybe there's high humidity, and the lightning is charging the humidity enough to trigger the GFCI?

What do you guys and gals think?

 

[pc1966]

GFCI are designed to look for small imbalances so it is not an impossibly big surprise it trips on lightning.

However, it really ought not to and it might be an indication that the circuit(s) connected to it are not quite as they should be. If the GFCI tests out OK (presumably USA electricians have a MFT equivalent to test this? @Megawatt ?) and there is nothing strange about the wiring you might want to consider having surge protection fitted to your distribution board.

That is now in the UK's 18th edition wiring regulations and I understand that it has become a requirement for new systems in the USA as well. But hopefully one of the forum's American members can comment more on this.

 

[Megawatt]

GFCI are designed to look for small imbalances so it is not an impossibly big surprise it trips on lightning.

However, it really ought not to and it might be an indication that the circuit(s) connected to it are not quite as they should be. If the GFCI tests out OK (presumably USA electricians have a MFT equivalent to test this? @Megawatt ?) and there is nothing strange about the wiring you might want to consider having surge protection fitted to your distribution board.

That is now in the UK's 18th edition wiring regulations and I understand that it has become a requirement for new systems in the USA as well. But hopefully one of the forum's American members can comment more on this.

@pc1966 your right the 2020 edition states all new services and panel change out Now require and you have to install an SPD. I was thinking of what @Lucien said y’all are not used to grounds are bare and the screws on the side is an accident or short waiting to happen. I wish we would do like y’all and at least make the ground with insulation. Thanks ?

 

[csdude55]

Thanks for the info! I've done a little research and found a few Type 2 SPD options in the $100 range, like the "Intermatic IG1240RC3 Whole Home Type-2 Surge Protection Device". I'm not finding a lot of info on how to install it, though... is this relatively easy to put in myself?

 

[Megawatt]

Thanks for the info! I've done a little research and found a few Type 2 SPD options in the $100 range, like the "Intermatic IG1240RC3 Whole Home Type-2 Surge Protection Device". I'm not finding a lot of info on how to install it, though... is this relatively easy to put in myself?

It should have on the package what size breaker that you use and you just hook it up to the double pole breaker. I prefer the SPD’s that attach to the panel by taking out a knockout And use the lock nut. They are fairly simple

 

[pc1966]

Thanks for the info! I've done a little research and found a few Type 2 SPD options in the $100 range, like the "Intermatic IG1240RC3 Whole Home Type-2 Surge Protection Device". I'm not finding a lot of info on how to install it, though... is this relatively easy to put in myself?

If in ANY doubt get a professional in to do it!

It is not that hard to do, but you also should check if you have any other restrictions on what electrical work you may do from local building regulations or your insurance policy. The instructions are here:

https://www.intermatic.com/-/media/inriver/12633-8970.ashx/IG1240RC3%20Installation%20Instructions%20EN

And show it coming of a dedicated double-pole 20A breaker. Again, if working on your distribution board you need to be very careful to safely isolate the power before attempting anything, and to have the means to safely prove you have made the busbars dead before touching anything. Don't rely on a multimeter for proving dead, use something like this:

https://www.homedepot.com/p/Klein-Tools-AC-DC-Voltage-Tester-ET45/308822920