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HPWC AND 14-50 install

Discussion in 'Model S' started by KCKIWI, Dec 30, 2016.

  1. KCKIWI

    KCKIWI Member

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    I have run #2 wire for L1&L2 and #4 for ground from a 100amp breaker in my panel to my garage for the HPWC. Was not planning on installing a 14-50 but have read others adding it as a backup in case of a HPWC failure. How would I also install the 14-50? Sub panel? Anyone have pics? Thanks for the help.
     
  2. steveho

    steveho Member

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    Is your garage attached or detached?

    I ran 2-2-2-4 to a detached garage with it's own 12 breaker panel. 90A breaker in the house (derated) to 100A breaker in the garage. 12 circuits in the garage from there. I ran 2x NEMA 14-50 circuits and I do not have HWPC.
     
  3. bradhs

    bradhs Member

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    I ran 100A to a HPWC and 40A 10-30R. At the time, car chargers commonly used 10-30's. Today you'd run a 14-50. And yes, I would definitely run both so that you could use your UMC if ever necessary.
     
  4. KCKIWI

    KCKIWI Member

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    My garage is attached
     
  5. BerTX

    BerTX Active Member

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    This is probably not the answer you want, but if you have to ask that question on a car forum, you should probably hire a licenced electrician. You can run another separate circuit for the NEMA 14-50, or run an additional common wire and put in a sub-panel, but there are lots of details that we just can't be sure you have done correctly. You can't put in a legal NEMA 14-50 on the wiring you describe.
     
  6. steveho

    steveho Member

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    Agreed. I originally was starting to write what could be done, but there are just too many possibilities. That's why I described what I did because it fits my situation and my garage (detached).

    @KCKIWI So in your case, you probably want to run your 2 gauge to your HWPC and a separate 6 gauge to a NEMA 14-50. Probably. Check with your local electrician though.
     
  7. Manzacoty

    Manzacoty Member

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    Big disclaimer here as I'm not an electrician. What if you made a sub panel and then split off the HPWC and a 14-50? To me that seems like the easiest and most logical. I'm just an accountant though.
     
  8. BerTX

    BerTX Active Member

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    The NEMA 14-50 will need a neutral wire to be to code. The Mobile Connector does not use it, but code will require it. The description of the wiring that has been done does not mention a neutral -- the Wall Connector does not use it, so it would have been a waste to run it UNLESS you plan to put in a sub-panel. Planning ahead is better than planning behind, but harder.

    But I'm not an electrician, either.
     
  9. oktane

    oktane Active Member

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    What's the benefit of feeding a 100A panel off at 90A breaker?
     
  10. BerTX

    BerTX Active Member

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    I assume you mean feeding a 100A breaker from a 90A breaker. None as far as circuit protection. Maybe, since there were 12 circuits in the panel, the panel installed was a main panel with a 100A main breaker? At that point it would just be a switch to allow all power to be cut from inside the garage.
     
  11. steveho

    steveho Member

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    90A breaker in the house because the wire is MHF wire and that has to be derated to 90A because it is feeding a subpanel. If it were feeding a mains, it could be the full 100A.

    The 100A in the subpanel is the whole garage shutoff required by code. It'll probably never trip, if anything the 90A in the house would trip first. [​IMG]
     
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  12. oktane

    oktane Active Member

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    Thank you sir for clarifying that. Your textual description makes sense to me. I assume this is your sub panel? If I am to understand your picture, 100 amp breaker at the top is going to your wall charger. However, how is there adequate power for all of the other breakers? Are there two separate buses?
     
  13. steveho

    steveho Member

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    No, the 100A is the feed from the house. It's the garage "main shutoff" as required by code. The lower two 50A circuits go to 2 NEMA 14-50 outlets, which is where I plug in my Tesla (into one of the two). The second NEMA 14-50 is for the future Model 3.

    I do not have an HWPC.
     
  14. aesculus

    aesculus Still Trying to Figure this All Out

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    I ran 1/0 to a subpanel on a 125 amp breaker. Then in the subpanel I have a 100 amp breaker for the HPWC and a 50 amp breaker for the 14-50.

    Of course if I was to run them both at the same time I would technically have to back the HPWC down a notch. The 14-50 is really for backup in case the HPWC goes south on me. Can still use the UMC in that case.
    20160613_140530 (Small).jpg
     
  15. whitex

    whitex Active Member

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    Does the electrical code require a safety switch near the HPWC when on 100A circuit (in addition to the 100A breaker)?
     
  16. Yinn

    Yinn Member

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    I had a HPWC installed (by a licensed electrician,) but my garage doors broke. I've been told it'll take 2-3 weeks to order new doors and get them installed. I've have been using my outdoor 14-50 as a backup for the past couple of days, so I definitely recommend installing one.

    My electrician ran the wiring from the main panel to a subpanel in the garage off of a 100A breaker - not sure on the wiring size. The subpanel has a 60A breaker that serves the HPWC. I did install the 14-50 myself, it goes from the subpanel off of a 50A breaker using 6/3 NM-B wire. The wire is run in conduit and goes into a 50 Amp Temporary Power Outlet mounted outside. (It's called temporary because it's not meant to be a permanent connection like the HPWC, it's meant to be plugged into when needed and unplugged when not in use. It is a fully hardwired outlet) The run from the subpanel to the 14-50 is about 10 feet. All said and done, it was less than $100 to run it since the electrician did the hard parts with the subpanel (including neutral) I'm not a licensed electrician though, just what I did.

    Depends on your area. I was told by my electrician, since my subpanel is in line of sight view and less than 20 feet away from the HPWC, an additional disconnect was not needed. If my panel were in another room, a disconnect would be required.
     

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