EV charger random ground faults

H

HaveBlue

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Location
CA
Occupation
GC
I was hoping someone had some ideas on this. About a year ago I installed a residential 40A Autel EV charger about 3' away on my 100A Murray panel from the 80s with a 50A #6/#10 thhn hardwired circuit. Checked all the lines, neutrals and the grounds including non related circuits for something loose but the charger occasionally faults out with a ground fault error. I'm not sure the house has two proper ground rods. Someone may have just gone to plumbing. Things are bonded in the main panel.

Resetting or plugging in the charger again and it works for a while. I've tested two different cars and it will fault eventually even if it isn't charging but just plugged in. Ie charging completed and later it faults.

Other thoughts were that something is wrong with the GFI in the charger. However lights occasionally flicker in the house and using a small welder causes the neighbors lights to flicker as well. The neighbor also causes my lights to flicker also welder use coincidently. The city came out but found nothing. Recently after a wind storm (well fire storm actually as 10k houses burned in my neighborhood) I inspected another neighbor's 200a panel up the block who lost his service drop to a tree and showed him the order to turn things back on later. He mentioned that he was thinking of replacing his two Tesla chargers because "they were old and erroring randomly."

This, of course, got me thinking even more about the city service having issues even before the storm.

So my questions, could a split phase imbalance on the line (city) side cause 240 gfis to trip? 120 gfi can function without a ground but I'm guessing that a 240 uses the egc ground lead as a neutral reference possibly. EV chargers don't have a neutral GC. Could better gec rod etc help? Could the city have a bad neutral? Anyway to diagnose a random situation like this?

I have a B license so at some level I'd include my electrician but I'd like to get some ideas. Thx
 
LADWP or Pasadena?

My money is on a combination of issues but more than likely it might be the utility. To get them to look into it is a bit harder. You will need to have some supporting data.

Put a logger on your service and a logger on the circuit to the charger.

I use PMI (Power monitor inc).

Record for about a month and mark down times where the charger stopped working. The same with the other noted issues like the welder. Mark when you use it.

You can use those waveform captures to get an idea of what is occurring.

I would also have your electrician take voltage measurements at the service with no charger and with the charger.
 
“Ground fault” in this context means that the unit has detected the lack of an EGC. It’s nothing to do with GFCI. I’m not sure how Autel detects the presence of the EGC, but if it’s looking for 120V (balanced) from each leg to the EGC, supply imbalance could be the cause.
 
Pasadena. Thanks for the PMI tip. I'll check the incoming voltage for drop under load. At the Charger it drops from about 240 to 233 only 3' away but that's a good idea to rule out the panel.

Bad EGC could be related to a bad ground rod setup so I suppose I'll take another look at earth.

We had our fair share of dead services and dropped legs at our buildings and just yesterday got everything back up and running. The City worked hard at it on their end as well but it took some meetings with Planners to sort out how to fix some of it. The County areas are Edison and there's not much left to electrify (below). My sister is staying with us from Palisades LADWP. Her condo building is one of the few that survived but won't have power for a while.

2025-01-19 21.53.23.jpg
 
The reason I asked about the utility is because they have different voltage systems and practices that could play into things.

As retirede said, it could be an issue with the way the EV charger has been wired rather than an issue with the utility. It could be sensing an open equipment grounding conductor (EGC) because of a lose connection or an improper splice.

I only jumped to that since you said more than one person has been experiencing the issue.

It could also be the way the welders are wired.

The best way to narrow it down is to get the recorders put in and start getting some captures.
 
Yep. If it was as simple as a loose green wire I wouldn't have posted. There's literally three foot lengths of #6 and #10 EGC going back to the breaker and ground/neutral bar in the main panel. I need to eliminate other possible issues before I continue warranty claim. I have Autel units at apartment buildings and they have no issues.

Autel's response for the error was:
Charger Faulty #6 Ground fault. A ground fault could result from voltage imbalances, loose connections, improper grounding, external leakage, or the charger's sensitive GFCI. Check wiring, grounding, and input voltages to ensure compliance with the manual and local codes.
 
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