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Over-current with ChargePoint NEMA 5-20

Discussion in 'Model S: Battery & Charging' started by mattmass, May 27, 2015.

  1. mattmass

    mattmass Member

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    Location:
    Cambridge, MA
    My apartment has a ChargePoint station with two connectors. One is a J1772, which charges at 208/30A very reliably. The other is a NEMA 5-15/20. I've had no trouble charging using the 5-15 adapter. If I try the 5-20, the station will trip an over-current fault after about 5-10 minutes. 12A charging is pretty painful, so I really want the 16A if I can get it. I've not tried messing with limiting charge current to find a sustainable current above 12A but below 16A.

    I've contacted ChargePoint and they claimed they do see "GFCI trips" on their end. I found that explanation unsatisfactory, considering the station itself is reporting detection of an over-current condition. Could just be the support person has limited visibility into the faults themselves, though.

    Has anyone else had similar issues with this type of station?
     
  2. cantdecide

    cantdecide Member

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    I think I had the same problem with a ChargePoint using the 5-20 in Palo Alto... But I rarely use that ChargePoint so I didn't follow up.
     
  3. DavidB

    DavidB Aug 2013 S85

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    Silver Spring, MD
    Try setting the charge to 14 Amps. Not as fast as 16 Amps, but still better than the 12 Amps.
     
  4. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    I'm guessing their software looks for > 15A on the 20A to shut down. I would try 15A and see if it holds steady there.
     
  5. mattmass

    mattmass Member

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    Following up on a fairly old thread here, but yes! 15A does indeed work just fine. Thank you!
     
  6. TacC

    TacC Member

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    Location:
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    Reviving an extremely old thread here. Any guess on what these stations are looking for on 5-15? I'm getting a ground fault at 12A and charging fine at 9A.

    FWIW, I'm also having less faults when I use an extension cord than when I only use the UMC. This is before the extension cord is detected by the car and it drops to 9A.
     
  7. DavidB

    DavidB Aug 2013 S85

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    Location:
    Silver Spring, MD
    I'm not an electrician, but the ground fault suggests to me that there is a wiring issue with the outlet. Perhaps screws aren't tightened enough, or the wires need better insulation.

    If you use a heavy duty extension cord, the car shouldn't detect the cord.
     
  8. TacC

    TacC Member

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    Location:
    East Bay, CA
    Thanks, David. That makes sense and the L2 just crapped out so it is probably time for an inspection.
     
  9. FlyingCookie

    FlyingCookie Member

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    Location:
    Nashville, TN
    Regarding the extension cord, If voltage drops too much (I think 110 needs to be above 102v, but i'm not sure), it'll reduce current. For 12A charge current, you need at least a 14AWG extension cord, but a 12AWG would be better. Extension cords are fine (I use one for a 14-50 at 40 amps all the time), but they have to be the correct wire gauge or it'll cause problems/be a hazard.
     

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