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HPWC with twin chargers, but says 40 AMPS?

Discussion in 'Model S: Battery & Charging' started by pbleic, May 12, 2014.

  1. pbleic

    pbleic Member

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    Feb 4, 2014
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    Location:
    Boston
    Can someone help me understand what is going on? I have an HPWC with a 100 AMP circuit breaker and a 200 AMP new service to the garage (separate meter). I have used it for about a week and thought it was charging at 80 AMPS. The car says 80 AMPs before I put the charger in. I have been charging to 70%, but today I charged elsewhere to 90% and drove the car home 15 miles, parked it in my garage, and put the charger in. Rated miles is 221. It says 40 AMPS, and can't be dialed up. I took it out, and the car reads 80 AMPS.

    Is there something wrong with the install? The HPWC? Does it charge more slowly if near the set limit? I don't understand why it wouldn't charge at 80 AMPs.
     
  2. RandyS

    RandyS Fan of Elon

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    There are small switches inside the HPWC that tell the unit what the maximum current flow should be when charging. Do you remember setting those to indicate 80 amps? They could be set at 40....See the manual and be careful of the ribbon cable when taking the cover off to change or look at the switches...
     
  3. pbleic

    pbleic Member

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    #3 pbleic, May 12, 2014
    Last edited: May 12, 2014
    My electrician installed. I am guessing you are right. Do you know what the default is? Probably 40?

    EDIT: Yep, that did it. Not a lot of fun getting the cover partially off; sliced a couple of fingers. But it was set for a 50 amp breaker.
     
  4. pgiralt

    pgiralt Active Member

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    When you install the HPWC, you are supposed to set all the switches to a Test position first, then change it to the position that matches the setting you want, so there really shouldn't be a default if the installer followed the instructions.

    Take a look at pages 14 and 15 here:

    https://www.teslamotors.com/sites/default/files/blog_attachments/high_power_wall_connector_installation_manual.pdf

    If you are sure the breaker is 100 Amp, you should be able to change this yourself. You'll need a Torx T20 driver to open the two screws on the bottom and then snap off the cover. Be careful because there is a ribbon cable that you need to detach.

    Be sure you turn off the breaker before you open it up!
     
  5. dsm363

    dsm363 Roadster + Sig Model S

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    Have you ever charged more than 40 Amps? Maybe one of the chargers isn't working although I would think you would be getting some sort of error message. More likely what RandyS said is right and that the HPWC isn't working.
     
  6. invisik

    invisik Member

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    Oh I had my HPWC dialed-in before handing it over to the electrician.... :) They can do the big stuff, but you gotta do the details. Glad it's working for you.

    -m
     

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