GFCI Outlet Tripping Sometimes

[user212_nr]

I rented a garage which has a 120v outlet. It worked fine with the UMC the first time that I tried it, but the second and the forth times tripped the GFCI outlet.

This is fine, as it works after resetting and only happened when plugging in (so far), but the garage door opener is daisy chained off that outlet and trips with it. So if, by chance it tripped with the door closed I'd be locked out.

I'm familiar with the gfci breaker threads here - advice is to replace them, but how are they broken? The UMC tests the ground, the outlet should trip.

Reason I'm asking is that if the outlet is broken I can ask for it to be fixed, but if it is working as-designed then it is a more complicated request.

 

[mswlogo]

The GFCI is not necessarily broken. It's just not compatible and false trips.

Not a ton of people use 120V, but you can search, ask around what is the recommended brand to use for the Outlet Style GFCI.

More expensive isn't necessarily better. It's just how the circuits are implemented.

You might see some comments in reviews on Amazon that reference one worked better than the other charging an EV.

I had a similar problem, when I changed my Pool to use a Variable Speed DC motor and 20A 240V GFCI started tripping.
The Electrical supply store knew exactly what the problem was with the breaker I had and exactly which breaker to switch too.

A good electrician might know what to switch to as well.

 

[Rocky_H]

If you search, you can find several threads about this (instead of starting a new one).

Problems charging at 110v on GFCI circuit

GFCI trips when charging starts

GFCI Outlet Tripping Sometimes

Issues with 110v gfic outlets

Apparently GFCIs are just really touchy with their specifications and getting a little "off" when they get old. I've been hearing of this quite often where either these GFCI outlets or GFCI breakers just go bad eventually, and Tesla UMCs will set them off really often--or always. Granted that the ground check that the UMC does is exactly the thing that the GFCI is supposed to be looking for and catch. They are looking for current imbalance between the two voltage lines. And the ground check is sending a little bit of that from one of them down the ground line to see if it is connected, so technically, the GFCI is doing its job. But they are supposed to allow a little bit of tolerance, and the amount the UMC uses to test is supposed to be small enough to not set them off, but it's stepping along the edge, so if the devices has aged, it can go off anyway.

Not much for it but to change out the outlet, and a newer one should be in spec enough that it should allow that UMC to do its thing without tripping.

 

[RayK18]

I have had this nuisance tripping occur. It occurred about 3 of 5 times.
I have recently tried a new method:
-1- I hold the charging cable for a few seconds to let any charge on my body equalize with the cable's state of charge.
-2- Then I touch the charging cable against the body of the car for a few seconds
-3- Plug it in

This has dramatically reduced the nuisance-tripping. I am 10 non-trips to 0 trips at the moment and counting. This experience is in Virginia, where the humidity, even in the winter, is relatively high, so the charge on the body is low compared to up north.
I hope this helps.

 

[mswlogo]

Some GFCI breakers will false trip on charging. Just try another brand. I think I had Leviton GFCI outlet and switched to Eaton and no more trips. Or was it the opposite, I forget.

Almost Every appliance I have with Inverters in them in my house will false trip GFCI. My furnace, fridge and well pump. And oddly my 240 V charging is allowing GFCI (but it used to trip on different breaker). They are all erratic too, could go hours, others are immediate.