Tesla EV charger/eaton breakers

Y

yo_ryco

Member
Location
Pennsylvania
Occupation
electrician
Hi All -

I am having an issue with a tesla gen 3 charger that has been installed in a new residential home. The client brought their existing charger from their previous home and had it installed in their new home. The service on the home is a 400a service with (2) 200a Eaton BR series panels and breakers. Everything in the home works completely find until the tesla charger is connected to the vehicle. Once the charging process has started, every gfci/afci/dfci breaker in both panels eventually trips. The timing and order of the breakers tripping is completely random. Breakers trip in both panels, on both legs of the service. We have checked and re-checked all connections multiple times. I am not able to find anything that is causing this problem within the panels or wiring of the home. It seems to be a problem with either the charger or the vehicle itself...Has anyone seen this before?
 
Just a follow up for anyone who might me curious/willing to weigh in on this. I made a site visit today and ran a few random tests.

1. I picked up a new dfci breaker to install as a test. I landed the breaker in the panel, but did not install any wiring on the breaker. When the Tesla charger was in use the breaker tripped...with no wires attached to it.

2. I learned that while the Tesla charger is in use, the "test" buttons on the breakers do not function. Some of the breakers blink 6 times, which indicates a failed auto test. When the breaker for the Tesla charger is turned off, the test buttons on all the breakers operate as they should. Eaton is claiming they have never heard of this before, and at this point is not able to offer any reasoning or solution.
 
ActionDave said:
They've heard of this before. Maybe the particular gentleman you were talking to at Eaton had not heard of a problem in this particular circumstance, but nuisance tripping AFCIs is well known in the industry and at Eaton.
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Never heard of the test buttons not working when something was in use, but they do have issues with nuisance tripping.
 
I agree with the nuisance tripping. We sometimes get nuisance tripping on appliance circuits, either with small appliances or with dedicated circuits for large appliances (washers, refrigerators). A large part of the reason we got away from leviton panels was due to the high amount of call backs we were having for nuisance tripping. On this issue, I'm at a loss...I've never had a breaker causing other breakers to trip. And I have never experienced the test buttons not working. That being said, I am not educated on how the internals of these breakers operate. I'm definitely leaning toward some kind of interference from the ev charger...or the vehicle itself. But, I can't prove that because I don't have an extra Tesla laying around the shop that I can take out and try. I took video today and sent it to Eaton, hoping from some kind of solution. Fortunately, the homeowner has been very easy to work with.
 
I’ve had multiple arc faults trip with minutes or seconds of each other, found out it was a loose connection at the utility transformer. They fixed it the first time, worked fine a couple of months, started again, same connection went bad again, so they changed to a different connector, haven’t had a problem since. Do they have an electric range or cooktop? If so, turn everything on, and try the test buttons again, and see if any of the arc faults trip. It may just be the heavy load causing an arc somewhere else, such as the main, or even on the utility end.
 
Thanks for the advice. I will check that...I am wondering if a drop in voltage would make the test button not operate? Seems like your suggestion would prove that out. Thank you.
 
hillbilly1 said:
It may just be the heavy load causing an arc somewhere else, such as the main, or even on the utility end.
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Interesting idea - and a good data point.

I would also suggest the "opposite" idea. If, as you indicate, the homeowner is easy to work with, have them dial down the charging current in the Tesla (car or app). For a standard Tesla L2 charger I think you can set it as low as 6A.

If the gfci/afci/dfci breakers hold, maybe that's a good thing to be aware of and let Eaton know about. Then dial it up until things start tripping. If things do hold at low current limits, maybe also a temp workaround for the customer?

Just thinking out loud.
 
yo_ryco said:
....I've never had a breaker causing other breakers to trip. And I have never experienced the test buttons not working.
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Other breakers tripping happens a lot with AFCIs. This is the first I've heard of the test buttons not working, but I have never heard of anyone checking that.
yo_ryco said:
That being said, I am not educated on how the internals of these breakers operate. I'm definitely leaning toward some kind of interference from the ev charger...or the vehicle itself.
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There is a microchip in there that monitors the current and trips when it sees a "dangerous" arc but doesn't trip when it sees a "normal" arc. Electronic loads mess with the microchip and cause nuisance trips.
 
ActionDave said:
There is a microchip in there that monitors the current and trips when it sees a "dangerous" arc but doesn't trip when it sees a "normal" arc. Electronic loads mess with the microchip and cause nuisance trips.
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This has been my primary objection to AFCIs. GFCIs work on an elegant principle easily demonstrated. AFCIs work on the "trust me bro" principle. Pay no attention to the man behind the curtain and all that.
 
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