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

HPWC plugged into 14-50 - is this ok?

Discussion in 'Model 3: Battery & Charging' started by Moderatefan, Apr 9, 2018.

  1. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    I'm considering my future charging setup...Have read few threads and saw few people mentioned their HPWC or UMC units broke and stopped working, so they are not totally dependable.

    Wondering if I can plug in HPWC into NEMA 14-50 outlet as a form of backup (if HPWC breaks, I can still use UMC with 14-50), also 14-50 will likely be more compatible with things non-Tesla. This also gives me the flexibility to have electrician install 14-50 and buy/self-install HPWC later.

    I've read that HPWC is supposed to be hardwired. However, my sauna heater said the same. I really didn't want to do this, b/c that would remove my flexibility to easily unplug/move sauna unit when needed.
    When I discussed this with my electrician (HVAC guy, actually) he said this doesn't make much difference, but gives manufacturer some leverage if, say, unit breaks and is on warranty and you want them to fix it, but they can say it was not wired up to spec, so it's your fault and we won't fix. Since my warranty on heater was only 1 year, I figured chances are pretty small I will need the warranty, so he added 14-50 outlet and the heater works fine since.

    Is it the same kind of deal for HPWC? Are there electricians here to clarify dangers of such setup, like:
    fires are more likely to happen;
    If someone(?) sees this setup, they will void house insurance, charge penalties for non-compliance, etc. ?
     
  2. oripaamoni

    oripaamoni Member

    Joined:
    Feb 2, 2018
    Messages:
    264
    Location:
    San Diego
    So I bought one of the rare units that comes from tesla with a 14-50 attached. As long as your wire going into the hpwc is well strain relieved and under 6ft you should be fine.
     
  3. idoco

    idoco Member

    Joined:
    May 7, 2013
    Messages:
    518
    Location:
    Outside Philly
    From FAQ FAQ: Home Tesla charging infrastructure Q&A
    ----------------------
    CAN I ATTACH A CORD AND PLUG TO MY HPWC AT THE 50A SETTING?

    In several threads on this forum, some have asked whether they may use their HPWC plugged into a NEMA 14-50 receptacle; this would allow them to unplug it and use their UMC in case of a wall connector failure.

    Technically, there is nothing in the NEC that prohibits the practice; Tesla's instructions don't explicitly call for only permanent wiring methods, and article 625 permits 240V devices to be plug-and-cord devices as long as they're "fastened in place". The only restriction is that the segment of cord prior to the ground fault protection (HPWC) must be a maximum of 12 inches in length (NEC 625.17(A)(3)(a)). Proper connectors, clamps, and strain relief connectors must be used.

    When consulted on the compliance of such a solution, several municipal and county inspectors have determined the practice to be legal based on the current instructions published by Tesla, and the NEC's requirements.

    However, when consulted, Tesla expressed concerns about the practice. The charging team responded to an inquiry with an explanation that the HPWC is designed to be mounted on a wall or post and wired using permanent wiring methods. There are concerns that a power cord could be yanked from the HPWC's terminals and expose live wires if, for example, someone or something grabbed the cord and yanked.

    A suggestion was made that Tesla note in the instruction/installation manual that permanent wiring methods are required, which would then be required by the NEC per section 110.3.
     
  4. rocksphoto

    rocksphoto Member

    Joined:
    Nov 2, 2017
    Messages:
    15
    Location:
    long island new york
    On youtube. Pretty well explained,

     
  5. oripaamoni

    oripaamoni Member

    Joined:
    Feb 2, 2018
    Messages:
    264
    Location:
    San Diego
    Not sure why they never officially released this product, seems to be a good amount of people interred in it.
     

    Attached Files:

    • Like x 3
  6. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    Well, the post from the FAQ pretty much says this is illegal and can be used to deny an insurance claim in case of a loss...especially if the fire started in that location (another FAQ topic "
    • SEVERAL TIMES IN THIS FAQ AND IN THESE FORUMS, YOU REFER TO INSURANCE AND LIABILITY ISSUES. WHAT DO YOU MEAN?)
    Thanks for sharing this. Shoot. Not an answer I hoped for.
     
  7. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    #7 Moderatefan, Apr 9, 2018
    Last edited: Apr 9, 2018
    Are you sure it came from Tesla, not a 3rd party?
    How long ago? Wondering if they had since changed their position as described in post #3

    Also found 3 options sold by Tesla in the past
    Home Charging Installation

    Your variation with 14-50 plug is not listed (bottom of the page)
     
  8. Daniellane

    Daniellane Active Member

    Joined:
    Aug 13, 2017
    Messages:
    2,190
    Location:
    Camas, Washington
    Are you limited to a 50 amp breaker?
    If not, I’d go hardwired HPWC plus a NEMA 14-50 either direct to the main panel if it’s next to it or to a subpanel with 2 breakers.
    My setup with a Backup NEMA 14-50.
    802D708B-DA73-4287-A6FB-C5565723BB48.jpeg
    HPWC on 100 amp Breaker Set to ON
    Backup NEMA 14-50 just below HPWC on 50AMP breaker set to OFF

    Also recently added a second HPWC which shares the 100 amp Breaker.
    F722D226-1835-4E99-A911-E572C67D90C2.jpeg
    18F748B9-2B33-41F1-8975-D19CCFD8C59F.jpeg
     
    • Like x 2
  9. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    Yeah, looks like your setup would be legal since HPWC is hardwired and 14-50 is a separate backup. Likely costs a bit more.
    I thought my subpanel would be ~60 feet away in the basement, not sure how that would complicate things for HPWC.
     
  10. oripaamoni

    oripaamoni Member

    Joined:
    Feb 2, 2018
    Messages:
    264
    Location:
    San Diego
    Ya its real for sure, Check out this youtube video on it. Mine is the exact one from that video, they sold it to me after they made the video.
     
    • Like x 1
  11. Daniellane

    Daniellane Active Member

    Joined:
    Aug 13, 2017
    Messages:
    2,190
    Location:
    Camas, Washington
    I’m not an electrician. As I understand it, adequate sized wire is required to account for distance. One advantage of a subpanel is it can act as an emergency cutoff.
    See this thread...
     
  12. Daniellane

    Daniellane Active Member

    Joined:
    Aug 13, 2017
    Messages:
    2,190
    Location:
    Camas, Washington
    Is this for a Model 3?
    If no this is may be an option:
    Model S/X Corded Mobile Connector
     
  13. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    Yes, this is M3 forum, so for M3. They sell similar gen2 UMC for S/X/3, which charges at max 32A vs 40A gen1(I believe can also be used for M3). I guess a bit slower compared what you can achieve with HPWC - direct connected to 60amp wire/breaker, the internal M3 LR charger can handle max 48 amp.
    If I plug in UMC into 14-50 receptacle (40amp continuous) then I'd be limited by UMC - either 32amp or 40amp.
    I guess it is also an option, I can buy 2nd UMC, which might be easier to handle (due to lighter cable) but will charge a bit slower.
    This one would be legal to plug in to 14-50. So, a bit less hassle/cheaper, but somewhat slower. I think even 14-50 is enough to fully charge a car overnight, so the difference is largely non-existent until for some reason you need to charge fast and don't have much time.
     
  14. Daniellane

    Daniellane Active Member

    Joined:
    Aug 13, 2017
    Messages:
    2,190
    Location:
    Camas, Washington
    It passed inspection.
     
    • Helpful x 1
  15. azentropy

    azentropy Member

    Joined:
    Mar 26, 2018
    Messages:
    127
    Location:
    Surprise, AZ
    Not sure why the didn’t release that version. Maybe couldn’t get the price point that would work. I’m probably going to just use my provided UMC at first at home as I figure 99% of the time I’ll charge at home, use a supercharger or a place that I’ll just need the j1772 adapter. But if a unit came out that provided 40A instead, could plug into my nema 14-50, and cost around the same as another UMC I’d consider it.
     
  16. Rocky_H

    Rocky_H Active Member

    Joined:
    Feb 19, 2015
    Messages:
    4,824
    Location:
    Boise, ID
    ...like the corded mobile connector?
    Model S/X Corded Mobile Connector
    Or do you really need the appearance of the wall mounted-ness?
     
  17. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    Gen1 is not reliable, that's why it's replaced by Gen2, plus $500 vs $300 difference... I think for $500 it makes more sense to buy HPWC.

    It's not just mounted-ness. It's more safe, more amps (for LR), and HPWCs can auto-split the charge among multiple cars on the same circuit.
     
    • Disagree x 1
  18. TexasEV

    TexasEV Well-Known Member

    Joined:
    Jun 5, 2013
    Messages:
    7,632
    Location:
    Austin, TX
    The Gen 1 UMC that came with my Model S was much more reliable— it lasted 4 years. So far I’m on my third Gen 2 UMC with my Model 3 which was delivered a month ago. The first one had a button so difficult to push that it usually didn’t open the charge port or release the connector. The replacement had ground faults intermittently (reproduced at the service center—it wasn’t my outlet). The replacement for the replacement has worked fine.
     
  19. Moderatefan

    Moderatefan Member

    Joined:
    Dec 20, 2017
    Messages:
    902
    Location:
    Denver, CO
    I said safe, not reliable. While defects are possible in both, I believe a number of people had issues with varying amperage and near fires due to plug/unplug cycles and bad connection/overheating at the outlet as a result; I think to deal with that Tesla reduced amperage, but maybe also to lower the price point due to thinner cable. Not guaranteeing, just a feeling I got from reading multuple threads here...
     
  20. TexasEV

    TexasEV Well-Known Member

    Joined:
    Jun 5, 2013
    Messages:
    7,632
    Location:
    Austin, TX
    Your post started by saying “Gen 1 is not reliable.”
     
    • Like x 3

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