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Any Issues Using GFCI Breakers for Charging Circuit?

Discussion in 'Model 3: Battery & Charging' started by RandomSample, Jan 4, 2020.

  1. RandomSample

    RandomSample Member

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    Hi Folks,

    Any issues with having their home charging circuit on a 30 or 40 Amp GFCI breaker?

    I understand that there are longer charging times on these lower amperage circuits.

    I'm still in my planning phase. This circuit/outlet will be in my garage.

    Thanks in Advance,
     
  2. ucmndd

    ucmndd Well-Known Member

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    The 2017 NEC is generally interpreted to REQUIRE GFCI on EVSE circuits, so no, it’s not an issue.
     
    • Informative x 1
  3. GHammer

    GHammer What a long strange trip its been.

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    Despite what NEC says, people have reported issues with having charging circuit on a GFCI. When the connector tests for ground it sends a small current that can trip the GFCI on some breakers.
     
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  4. marco33

    marco33 Member

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    Before I installed my 220, was using a 20amp 110 GFI. in the three week period the GFI tripped three of those days. One day it tripped like three + times in a row, that was very annoying as the reset was in the basement.
     
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  5. theeskimo

    theeskimo Member

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    #5 theeskimo, Jan 4, 2020
    Last edited: Jan 4, 2020
    According to the electrician who did my NEMA 14-50 install who has done “countless” other Tesla specific installs in my area, Square D breakers seem to be more tolerant and cause fewer ground faults than any other brand of breaker he had used in an install. So far I have had zero trips while maxing out my mobile connector.
     
    • Informative x 1
  6. ElectricIAC

    ElectricIAC Devil’s Advocate

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    Our 14-50 has an Eaton GFCI box which regularly made the Gen2 UMC lose its ever loving mind: My solution? Buy Gen1 UMC and enjoy 40A charging.

    I’m aware this isn’t *ideal* but after giving up trying to find a 14-50 plug HWPC or at least a modified one this was the next best thing. For your setup what’s truly stopping you from just going 50A?
     
  7. Scrannel

    Scrannel Member

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    I believe California is on the 2014 NEC. Thus, my guess is, GFCI breakers are not required. The Mobile cord -- and I think all Tesla cords -- have some sort of GFCI built in. Thus, as others have pointed out, the cable can cause an external GFCI to trip. Just from what have been reading in several forums. I am not an electrician.
     
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  8. RandomSample

    RandomSample Member

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    Thanks for the info everyone. My first preference will be to go for a 50A circuit in the garage. However, it has to be GFCI because it will be serving a dual purpose besides charging a Model 3.
     
  9. doghousePVD

    doghousePVD My grandfather’s car

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    The NEC code is complicated and appears to be inconsistent. Verify if in your jurisdiction you actually need GFI for your alternate use.
    I believe stoves never need GFI. Depending on which NEC is in force most RV plugs (14-50) do not require GFI.

    My understanding is all EVSE have built in GFI.
     
    • Informative x 1
  10. mongo

    mongo Well-Known Member

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    As general data:

    The GFCI in an EVSE trips at 15-20mA, a standard residential outlet trips at 5mA.
     
  11. Scrannel

    Scrannel Member

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    Just read that although California is on the 2014 NEC, it may be on he 2015 NEC for residential.
     
  12. WilliamG

    WilliamG Active Member

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    Why 50A and not 60A?
     
  13. GPinzone

    GPinzone Member

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    Are you implying the 2017 NEC was well thought-out? The GFCI requirement was thrown in at the last moment.

    BTW, if you tell an electrician you want a NEMA 14-50 outlet installed and don't say why, then what?
     
  14. rokitnerd

    rokitnerd Member

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    Now that it's been 9 months do you still have no issues with tripping?
     
  15. theeskimo

    theeskimo Member

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    Yep! Still zero issues 1 year and 4000 kWh later :)
     
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  16. valaeyron

    valaeyron Member

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    I have a 240V / 50A line (shared between the unused outdoor hot tub and beloved 14-50 in the garage) on a GFCI. Never an issue...
     
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