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HPWC popping my house fuse

Discussion in 'Model S: Battery & Charging' started by joer00, Oct 27, 2013.

  1. joer00

    joer00 Member

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    I just installed the HPWC temporary on our lto where we build a new house. I only have 70 amps there, so the HPWC was put on a 60 amps breaker. I did set the switches in the HPWC to 60 amps and the car reports loading at 48 maps. After one hour the 60 amp fuse is popping.

    Is the fuse bad ? Are there bad quality fuses which might not be designed for CONSISTENT load ?

    Anybody else with this problem ? (I had a 14/50 there first which got burned !! So I though the HPWC will fix this problem, now I just have a new one !)

    Joe
     
  2. FlasherZ

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

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    If the car is only reporting drawing 48 amps, and it's attached to a 60A breaker, I'd suspect a bad breaker first. There is a remote chance it could be some type of a high-resistance fault to ground between the HPWC and breaker but that would be a <1% corner case. Replacing the breaker will likely fix the problem.
     
  3. yobigd20

    yobigd20 Well-Known Member

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    48amps on a 60amp breaker is exactly what it should pull. You can only pull 80% of rated capacity. That's why for 100amp you pull 80, 80amp you pull 64, 60 amp you pull 48. 50amp you pull 40.

    If you are constantly tripping the breaker this is a very dangerous situation. Breakers trip through overheating. If it starts overheating and a breaker is faulty this is how houses burn down and people die. It sounds like you did the install yourself. It also sounds like you are not a professional certified electrician and you don't know what you are doing based on the way you worded your questions (no offense).

    The most worrying this to me is also that you said you melted down or burned out your other plug first and so you just swapped it with a HPWC. If you simply swapped that with a HPWC using the same wiring this is probably the most dangerous situation as the wiring is not the right gauge and I'm quite surprised that a fire hasn't started already.

    You need to immediately stop using this circuit and get a real electrician in there to make sure everything is wired and hooked up correctly. This is not something you want to mess with yourself. You can kill yourself with this type of current and others in your house if miswired or not using the right size wiring.
     
  4. FlasherZ

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

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    That was not a statement of it being a bad breaker because it drew 48 amps, it was a statement of it being a bad breaker if it was tripping while only drawing 48A. Some people have installed the HPWC on a smaller breaker and they trip it because they set it to 100A. I'm aware of what can be drawn as a continuous load.

    My point is this - it sounds like the HPWC is set up correctly (it draws 48A, therefore it's set to the 60A setting), and if it is tripping a 60A breaker, it's likely a defective breaker.

    Now that I think about it, there is one thing to check - check the screw on the breaker to ensure it is tight. Heat at the breaker contacts can cause the breaker to trip prematurely.

    As for the other plug melting, without a picture of the damage we can't tell why this might be the case but I'm willing to bet loose contact.
     
  5. Chris TX

    Chris TX Active Member

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    1. As others have noted, the breaker could be weak/bad.
    2. What gauge wire are you using? How long is the run from the box (sounds like it's fairly close)?
    3. Last but most important, how are you getting the 240V? 3-phase Wye or Delta? If 3phase, are you sure you've got p1-p3 labeled correctly?
    4. And the obvious one is, have you read the manual ;)
    https://www.teslamotors.com/sites/default/files/blog_attachments/ms_hpwc_installation_guide.pdf


    Also, as others have stated, the melted UMC is kinda strange.

    I would check to see how clean the power is going into the main breaker. If THD is high on the other end, you're going to have issues with everything. I wouldn't want to connect a house to that power, if that's the case.
     
  6. FlasherZ

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

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    It's most likely he has single split-phase, as this is a residence.

    Not really strange. 40A will generate a LOT of heat on a loose connection, whether the prong on the outlet is loose, or the wire wasn't torqued properly, or the conductors were nicked when stripping the wire.

    This is one of the last things to check.

    I've had a number of breakers bad right out of the box. They're cheap. Replace it, ensure the connections are torqued right, and I'll bet it fixes the problem.
     
  7. rlang59

    rlang59 Member

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    He posted the 14-50 on another thread.
    http://www.teslamotorsclub.com/showthread.php/19576-Burned-220V-Adapter/page2?p=472370&viewfull=1#post472370

    Looks to me like the screws weren't torqued correctly. If it was wrong at the outlet, it's probably wrong at the breaker.
     
  8. FlasherZ

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

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    Ah yes, I recall that one. The melted box is a suggestion the wires weren't torqued properly at the back of the receptacle, whereas loose prongs in the receptacle would have created more damage to the UMC adapter and front of the receptacle.

    Replace the breaker even if you find the lugs weren't torqued enough at the breaker panel - this is because heat may have damaged the mechanism in the breaker. They're less than $15, and it pays to be safe.
     
  9. jthompson

    jthompson JThompson

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    ok - I am not an electrician nor an electrical engineer. But I thought you had to run 100 amp service to the HPWC? That's what I have in my setup, and I have no problems running at 80 amps into the car (before Tesla software update stepped it down to 60 amps in the car).
     
  10. FlasherZ

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

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    No, the HPWC is configurable with several different circuit sizes. The car will only charge at 80% of the setting (the continuous load rule).

    In this case, the OP only has capacity for a 60A circuit (48A charging).
     
  11. jthompson

    jthompson JThompson

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    Thanks, FlasherZ!
     

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