TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Need advice on temporary charging solution until HPWC arrives

Discussion in 'Model 3' started by Merle Corey, Apr 12, 2018.

  1. Merle Corey

    Merle Corey Member

    Joined:
    Apr 1, 2016
    Messages:
    65
    Location:
    Brambleton
    Slight problem.. I got my invite a couple days ago and configured. ETA is 3-6 weeks. That’s the good news. Problem is that I don’t have my charging situation taken care of yet! I am buying a black signature HPWC from one of the other members here, but it won’t be here until June. In the meantime, I was just going to have an electrician wire up a temporary 220v plug so that I can plug in that way. I’m assuming that he can come back when the HPWC is here and then use the existing wiring that he installed to connect it. Does that work? Or are they two separate installs and he can’t reuse the 220 wiring/connection?
     
  2. eSpiritIV

    eSpiritIV Member

    Joined:
    Mar 24, 2016
    Messages:
    434
    Location:
    Portland, OR
    The difference in time for an electrician to connect one or another cant possibly be more than a half hr. You will want to pull your #6AWG THHN wire in conduit, and 50A circuit breaker. Only difference is to install a 4 square electrical box and NEMA 14-50 Plug to connect to vs just connecting into the HPWC.

    Pulling the wiring is the hardest part.

    If you think you have no other charging options till your install, you can always just wait for the HPWC to arrive in the mail
     
  3. Galve2000

    Galve2000 Active Member

    Joined:
    May 20, 2013
    Messages:
    1,015
    Location:
    NYC
    Should work fine as long as the electrician uses the correct wire gage for the amount of current you want the HPWC to pull when it eventually gets installed. Otherwise it is a simple swap from whatever NEMA plug you are installing to the hard-wired HPWC.

    In the very olden days before the HPWC was available this is what Tesla recommended be done by the 1st batch of lucky owners.
     
  4. boaterva

    boaterva Supporting Member

    Joined:
    Apr 2, 2016
    Messages:
    7,465
    Location:
    Northern Virginia, USA
    Right, an HPWC can run on any circuit from 240 V 15 Amps to 100 Amps (12 to 80 effective). If you are going to end up with 50 Amps (40 usable), install a 14-50 and use that; easy to switch over.
     
    • Like x 1
  5. jaguar36

    jaguar36 Active Member

    Joined:
    Apr 10, 2014
    Messages:
    1,957
    Location:
    NJ
    Once you've got a 14-50 installed you may find there is no need to buy a HPWC.

    We've got two S's and have never had a problem with just a single 14-50 outlet.
     
  6. Derek Kessler

    Derek Kessler Active Member

    Joined:
    Apr 15, 2016
    Messages:
    1,193
    Location:
    Cincinnati
    #6 Derek Kessler, Apr 12, 2018
    Last edited: Apr 12, 2018
    Depending on how much you drive in a day, you might be able to get by charging off of just a NEMA 5-15 outlet (that's your standard 15-amp 120-volt household 3-prong outlet). Model 3 should do 4-5 miles/hour off that.

    Once you get the NEMA 14-50 installed, there's not a compelling case (in my opinion) for a HPWC, aside from that it looks nicer (or if you really need the charging speed). Your Model 3 will top out at 48 amps (which requires a 60-amp breaker), while 14-50 will deliver a continuous 40 amps.


    Circuit BreakerMax ampsModel 3 charge speedFull charge time
    15 amps, 120 volts (UMC)12 amps5 miles/hour2:13:55
    50 amps, 240 volts (UMC)40 amps37 miles/hour8:22
    60 amps, 240 volts (HPWC)48 amps44 miles/hour7:03
    Source: Tesla
     
    • Helpful x 1
    • Informative x 1
  7. X Fan

    X Fan Supporting Member

    Joined:
    Sep 29, 2015
    Messages:
    2,295
    Location:
    Naples, FL & OIB, NC
    ^^^^^^^
    +1 and typically will never need to charge that long.....
     
  8. rhaekar

    rhaekar Member

    Joined:
    Nov 9, 2017
    Messages:
    452
    Location:
    San Diego
    Charge rate shouldn't matter that much if you're charging over night. It really comes down to if you want to always have your UMC in your car then you have to unpack it and pack it up whenever you home charge.
     
  9. brkaus

    brkaus Well-Known Member

    Joined:
    Jul 8, 2014
    Messages:
    6,994
    Location:
    Austin, TX
    Yes, overnight charging is great!

    And there really isn't much need for a UMC in the car, unless one travels to visit family, etc. I've used my UMC away from home one time in 1 year / 20k miles.

    Most charging around town is J1772, which only needs the adaptor.
     
    • Like x 1
  10. drawfour

    drawfour Member

    Joined:
    Mar 10, 2018
    Messages:
    774
    Location:
    Seattle, WA
    You can buy a second UMC for cheaper than the HWPC, right? So then you have one in your car for when you need it and one at home. Bonus: if one of them breaks for some reason, you have a replacement right away (unless you're actually out on a long trip when that one breaks).
     
  11. rhaekar

    rhaekar Member

    Joined:
    Nov 9, 2017
    Messages:
    452
    Location:
    San Diego
    $300 for a gen2 UMC, $500 for a HPWC. For $200 extra, you get a better looking charger and faster charging rate if ever needed in case of an emergency. You can also get the HPWC in 24' vs 20' of the UMC.

    It's really just a preference. I went with the HPWC.
     
    • Like x 3
  12. Merle Corey

    Merle Corey Member

    Joined:
    Apr 1, 2016
    Messages:
    65
    Location:
    Brambleton
    Thanks for the helpful chart!

    Hmm.. making my decision harder. Was all set on the HPWC, but I guess it does only offer better looks. I'll be doing less than 40 miles a day on average, so speed of charging is not important.

    If anyone has some pictures of their HPWC and or NEMA outlet in their garage, that would be good to see. I guess I'm just trying to convince myself to get the nicer looking charger since I'll literally be using it everyday! LOL
     
  13. drawfour

    drawfour Member

    Joined:
    Mar 10, 2018
    Messages:
    774
    Location:
    Seattle, WA
    If you think a non-Tesla EV might be in your future, then the NEMA 14-50 will work for both your Tesla and the other. I'm debating that right now - I doubt my wife will want a Model 3 - expensive plus she's really not all that "gadgety". But she might upgrade her 2010 Prius to an EV or plugin hybrid. If she did that, we could have one charging port and satisfy our needs. Or get the Tesla one and have a NEMA 14-50 installed next to it, so we each get our own. Who knows.
     
    • Like x 1
  14. Derek Kessler

    Derek Kessler Active Member

    Joined:
    Apr 15, 2016
    Messages:
    1,193
    Location:
    Cincinnati
    Here's my UMC (Gen 1) setup:
    C0BF0855-3991-45FE-808E-B0CC658B4CA9.jpeg
     
    • Helpful x 1
    • Informative x 1
    • Like x 1
  15. SageBrush

    SageBrush 2020: Drain the Sewer

    Joined:
    May 7, 2015
    Messages:
    11,130
    Location:
    New Mexico
    The car comes bundled with a UMC. You only spend $300 to have another.

    For reasons that are not clear to me, electricians tend to charge a lot more to hard-wire an HPWC than to install a 14-50 outlet. Perhaps it is that Tesla brand at work.
     
    • Like x 1
  16. SageBrush

    SageBrush 2020: Drain the Sewer

    Joined:
    May 7, 2015
    Messages:
    11,130
    Location:
    New Mexico
    There is not a lot to show about a 14-50 electrical socket.
     
  17. drawfour

    drawfour Member

    Joined:
    Mar 10, 2018
    Messages:
    774
    Location:
    Seattle, WA
    That's what we were talking about. Keep your UMC that comes with the car in the car at all times so you have it when on the road. Have another plugged into your NEMA 14-50 at home at all times so it's available. No worries about unplugging it at home and leaving it there and not having it with you. It was for the convenience, just like installing a HPWC is for the convenience...
     
  18. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    #18 Moderatefan, Apr 12, 2018
    Last edited: Apr 12, 2018
    From me reading other threads...
    - the new UMC gen2 can charge @32amp, which is below 40amp (continuous) capability of NEMA 14-50 receptacle.
    - the old UMC gen1 can charge @40amp, but is unsafe/prone to failing, which is why Tesla switched to gen2, so don't buy.
    - HPWC is safer due to no plug/unplug cycles & can charge @80amp, but you'll be limited by car's charger - LR @48amp and SR @32amp
    A lot of info here: Home Charging Installation

    In my opinion, HPWC probably makes sense if you expect to have multiple Tesla vehicles charging significantly - then you do the wiring once @100amp and later just add more HPWCs to the same curcuit. (consider how likely you are to buy Y in the future :) )

    On the other hand, you may have one Tesla used for longer commutes, road trips etc. that needs significant daily charging and other Tesla for short local trips - I see many people report successfully using NEMA 14-50 + UMC and a regular CGFI 110V outlet + UMC for 2nd car in this scenario.

    See nice pictures from Daniellane here: HPWC plugged into 14-50 - is this ok?
     
    • Informative x 1
  19. dhrivnak

    dhrivnak Active Member

    Joined:
    Jan 8, 2011
    Messages:
    4,266
    Location:
    NE Tennessee
    It is also VERY easy to add a plug to an HPWC and plug into a NEMA 14-50. If you do this make sure you dial it back to 40 amps. Easy to do.
     
  20. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    This is illegal as a permanent solution per thread I referenced, specifically
     

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC