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Plug HPWC into a NEMA 14-50 plug?

Discussion in 'Model S: Battery & Charging' started by tomp, Dec 4, 2013.

  1. tomp

    tomp Member

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    Hi -
    I'm considering the high power home charging option, largely because of the dual charger. I don't need HPWC charging speeds at home. Instead, I'm thinking of installing a NEMA14-50 outlet. Conveniently, the location will be directly next to our main breaker. Also, the NEMA 14-50 outlet will be useful in charging our Leaf.

    My question is - can I wire the HPWC to plug into the 14-50 outlet via a male plug (setting the dip switches to 50A)? Meaning, rather than have it hard-wired. Additional benefit here is that it's easy to move in the event we relocate.

    Thanks!
    tomp
     
  2. jcaspar

    jcaspar Member

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    Don't see why you couldn't but why not just use the UMC and sell the HPWC?
     
  3. tomp

    tomp Member

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    Didn't realize there was a market for HPWCs. The other benefit is then I can keep the UMC in the car always as a backup.
     
  4. Chris TX

    Chris TX Active Member

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    People sell their HPWC all the time in the Tesla Parts for Sale section.

    Out of curiosity, why did you get dual chargers if you are fine with the 40A charging you'll get from a 14-50 outlet?
     
  5. tomp

    tomp Member

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    To clarify, I haven't ordered the car yet. The thought is to get the dual chargers to be able to take advantage of HPWC at Tesla store/service locations, private locations, or potential (rare) high amp J1772 chargers - primarily in the event of road trips to give some additional flexibility.

    Thanks.
     
  6. Klaus

    Klaus Member

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    You can sell the HPWC and buy a second UMC for the home charger with 14-50 adapter for $525 + tax, leave the original UMC with all adapters in the car for the road. That's what I did (after buying and returning the HPWC.) About $700 price difference.

    I don't believe that plugging a HPWC into a 14-50 outlet is up to code and likely won't pass inspection, and for the hardwired installation you'll need a disconnect switch between the breaker and the HPWC. Setting the HPWC to a 50A breaker will give you 40A charging, same as the UMC.
     
  7. FlasherZ

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

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    It's a gray area, but bottom line is that you should be okay with it.

    If you call the HPWC electrical infrastructure, it is subject to code and would likely be considered violating code by an AHJ because NEC 625.13 requires that it be tested & listed as "suitable for the purpose" to be connected with cord-and-plug (otherwise all EVSE must be hard-wired and fixed). The HPWC is indeed listed, but it was listed as a direct-wire unit; adding a cord-and-plug set invalidates the listing. Your AHJ (authority having jurisdiction, the official inspection authority) might find it acceptable in any regard; (s)he has final say as to whether something is acceptable under NEC and local codes.

    On the other hand, you could argue that the HPWC is an electrical appliance and the NEC doesn't apply; in that case it would no longer be listed, but would be a safe application provided that the DIP switches were set for a 50A circuit, a proper #6 cord and NEMA 14-50 plugs and receptacles are used.

    My recommendation, however, would be to provision the garage with a small subpanel for EV charging, and then have a short run to the HPWC. That way, the removal of the equipment if you move is relatively simple and the home is left with provisions to charge other EV's should the new owners have one.
     
  8. scaesare

    scaesare Active Member

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    I understand your primary point is regarding the potential to plug the HPWC in to a recpticle rather than hard wire, but since the suggestion of just using your UMC came up, in another thread the issue of HPWC vs. UMC came up for "daily charging", and I mumbled something like the following:

     
  9. Puyallup Bill

    Puyallup Bill Member

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    Get the dual chargers. Talk to Tesla about unbundling - they will do it. It was a dumb move to bundle, as there are CS 90s all over Canada and breeding rapidly in my neck of the woods. Canadians do not have to purchase both.
     
  10. brianman

    brianman Burrito Founder

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    Given the underlined, another option to consider (as pointed out in another thread) is to go ahead and get the HPWC, install it at "full powa!" and consider becoming one of those "private locations" for the benefit of other drivers.
     
  11. tomp

    tomp Member

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    Thanks to all for the helpful replies.
    Good point - I have considered this. Downside is then I can't use the NEMA 14-50plug to charge our Leaf.
     
  12. dhrivnak

    dhrivnak Active Member

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    It can be done and I am doing this successfully for over two years now. The plug has a 50 amp rating but you said you would limit your HPWC. Just don't unplug when charging which should be easy to do. Arcing can occur when unplugging under load.
     
  13. tomp

    tomp Member

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    Thanks - great to know. Was there anything special to know/do when wiring the HPWC to a 14-50 plug? I presume you used an electrician?
     
  14. montgom626

    montgom626 Active Member

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    Why do that?
     
  15. Cosmacelf

    Cosmacelf Active Member

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    Isn't it going to be a bit of a pain charging two vehicles from one plug? If your panel can support another 50A breaker, I would at the very least add an additional 14-50 so that you can charge both cars at the same time. Usually, electric companies offer time of use rates to EV owners giving you electric price breaks for charging at midnight. To take advantage of this, you'd have to have two plugs, one for each EV.

    Even if you did hard wire the HPWC, moving it won't be that hard. Flip the breaker off, then open up the HPWC, unbolt the three wires going into it from the conduit and then you can take the HPWC away. As a final step, you would open up the breaker panel and unscrew the wires going into the HPWC breaker and cap them off with wire nuts. Then label the HPWC breaker as unconnected.

    As others have mentioned, you can sell your HPWC and buy another UMC instead - you can buy Tesla's cord hanger (http://shop.teslamotors.com/products/replacement-high-power-wall-connector-cable-organizer) which works great with the UMC and gives you the same functionality as the HPWC as far as cable organization.

    Personally, I would keep the HPWC and hardwire it to the highest breaker size my panel could support. You never know when you'll have done a ton of driving one day and need a bit extra for going out at night. Good call on getting the dual chargers, they do come in handy from time to time.
     
  16. tomp

    tomp Member

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    Thanks - in our case having only one plug is OK since we can both generally charge at work. Plus, currently, my wife charges her Leaf via work and supplements when needed via a 120V plug at home.

    Good input on ease of disconnecting the HPWC. I didn't realize it was that straightforward.

    Thanks!

     
  17. dhrivnak

    dhrivnak Active Member

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    No I wired it myself. It is a simple connection just get a quality plug and I used #6 wire. Now I normally charge at 40 amps but have tested and even stress tested at 64 amps for 3+ hours.
     
  18. davewill

    davewill Member

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    If you want to charge your LEAF from the same circuit, wouldn't it make more sense to skip the HPWC and put in a 40a J1772 unit? Then you don't have to have the 14-50 (unless you want to), and you don't have to keep plugging and unplugging two EVSEs. You could put in up to a 70a unit and STILL charge the LEAF from it.

    Standards exist for a reason.
     
  19. tomp

    tomp Member

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    So some further digging revealed that our Leaf actually can't charge via a Nema 14-50. I'm not sure if htat's because we only have the lower level charger or what. But, I decided to skip the NEMA 14-50 and just install the HPWC as intended - hardwired with a 100A breaker.
    Thanks,
    Tom
     
  20. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    You have to have the aftermarket fix for the charge cable, otherwise it's just 120V.
     

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