EV Chargers tripping GFCI breakers

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Chamuit

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
Anyone had trouble with Lvl 2 EV chargers tripping out GFCI breakers? (Req by 2020NEC)

I have a site where I have installed 3 separate EV chargers on 2 different circuits (different panels too) with 3-wire and 4-wire configurations. One at the main panel and one at a sub-panel. The chargers are constantly tripping the breakers with no discernable correlation to other activities on-site and never while actually charging. The wiring was all brand new at the time of install. I did not meg the wires.

The chargers are not new. I'm wondering if they have trickle voltage to the ground to light the LEDs internally. A WAG on that.

I even set a Nest camera up to watch both charger locations simultaneously for surreptitious activities and nothing.
 
Need more info.
In my experience over the last few years. Most EV's trip the GFCI on overload not ground fault
One possibility:
Owners ask for a 40 amp circuit then crank up the charge rate to it's highest point, causing it to trip after a few hours.
I try to hard wire whenever possible to avoid the GFCI protected receptacle requirement. The hardwired EV chargers I've installed have GFCI protection built in.
 
LarryFine said:
I thought the max current selection was automatic.
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The fixed equipment (EVSE) is just a switch with an extra pilot signal to tell the EV how much current it may draw. So a particular EVSE model will have a maximum current it is built to carry. Some have a fixed pilot signal and require you to install it on an appropriately sized circuit; some let you turn down the advertised current so you have the option to install the EVSE on a smaller circuit. In the latter case, if you go back after the install and turn up the current setting, then you can easily cause the circuit to trip on overload, when an EV with a sufficiently large on board charger is connected.

As to the GFCI tripping, since the AC-to-DC is on the car, it could be the case that a certain model of car or even a particular car has a particular noisy charger, or a greater than designed leakage current, causing the EVSE's GFCI circuit to trip. Just one more possibility to bear in mind, in addition to problems in the fixed equipment.

Cheers, Wayne
 
The controller has factory built in ground fault protection, and probably self tests. That is probably what is causing the tripping. Another issue that wasn’t thought through to well with 2020 requirements.
 
Chargers are wired and breakered appropriately. Plus, you tell the chargers what size (breaker amperage) circuit you have, 40 or 50.

Breakers are tripping while NOT in use. Never when in use.
 
hillbilly1 said:
The controller has factory built in ground fault protection, and probably self tests. That is probably what is causing the tripping.
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If the controller self tests by shunting a resistor to the EGC, then that could cause a GFCI breaker to trip. But if it self tests by putting a current though a separate winding on the CT (which some GFCI's do), then that wouldn't apply any ground fault current that could trip a GFCI breaker.
 
I know this isn't an answer for you.
I have of one customer who has to "reboot/ reset" his Tesla EV chargIng station every once in a while because it shuts down. (He's never conveyed to me the details why, he may not know). Sounds very inconvenient.
It is a hard wired unit.
 
We just today had an issue with a Grissl-E plug in charger stripping the GFCI. After looking into the manual it states,

"The Charging Unit has a built in GFCI protection; do not provide any additional GFCI
protection upstream of the charging unit."
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It also states,

The Charging Stations can connect a Standard NEMA 6-50 or 14-50 Receptacle, or the unit
can be hardwired
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Based on that it seems like the only legal way to install it where NEC 625.54 is required is to hard wire it and NOT install GFCI protection at the circuit breaker. Would you all agree?
 
marmathsen said:
We just today had an issue with a Grissl-E plug in charger stripping the GFCI. After looking into the manual it states,



It also states,



Based on that it seems like the only legal way to install it where NEC 625.54 is required is to hard wire it and NOT install GFCI protection at the circuit breaker. Would you all agree?
Click to expand...

I would agree.

I believe there are also some EVSEs that do not have provisions for hardwiring that specify no GFCI. Those will be a real problem!
 
marmathsen said:
We just today had an issue with a Grissl-E plug in charger stripping the GFCI. After looking into the manual it states,



It also states,



Based on that it seems like the only legal way to install it where NEC 625.54 is required is to hard wire it and NOT install GFCI protection at the circuit breaker. Would you all agree?
Click to expand...
What year code is 625.54, I don't think we have that in Calif.
 
It's a TIA for 2017, so if you are under the 2017, the question is whether your jurisdiction adopted the TIA. I don't know about California.

Cheers, Wayne
 
wwhitney said:
It's a TIA for 2017, so if you are under the 2017, the question is whether your jurisdiction adopted the TIA. I don't know about California.

Cheers, Wayne
Click to expand...
We are on the 2017NEC CA might have adopted a amendment, however I cannot find it.
 
To my knowledge California does not typically adopt TIAs. I found a bulletin online from the CA code commission advising localities of changes to 625 and that they need to either enact a local ordiance or permit alternative methods. These sections are also not in the supplement that goes into effect July 1st. So you basically have until 2023 in California.
 
jaggedben said:
To my knowledge California does not typically adopt TIAs. I found a bulletin online from the CA code commission advising localities of changes to 625 and that they need to either enact a local ordiance or permit alternative methods. These sections are also not in the supplement that goes into effect July 1st. So you basically have until 2023 in California.
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What is the issue that GFCI is necessary? The neutral is not used or really needed in most if not all EV charging. I do not know why this configuration was adopted. Are we supposed to think that a EV owner is going to run an extension cord to the kitchen and plug in. If so , we should not have to protect from stupid.
 
Sierrasparky said:
What is the issue that GFCI is necessary? The neutral is not used or really needed in most if not all EV charging. I do not know why this configuration was adopted. Are we supposed to think that a EV owner is going to run an extension cord to the kitchen and plug in. If so , we should not have to protect from stupid.
Click to expand...
Neutral is not required for a GFCI to serve a purpose. I assume the concern is the potential wet environment and the fact that users are constantly plugging in and unplugging the cord set.

Sent from my Pixel 4 XL using Tapatalk
 
Sierrasparky said:
What is the issue that GFCI is necessary? The neutral is not used or really needed in most if not all EV charging. I do not know why this configuration was adopted. Are we supposed to think that a EV owner is going to run an extension cord to the kitchen and plug in. If so , we should not have to protect from stupid.
Click to expand...

Basically the same reason GFCI is now required for every receptacle outlet in a residential garage.
 
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