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48 amps through a 50 amp NEMA 14-50?

Discussion in 'Supercharging & Charging Infrastructure' started by Ruffles, Feb 18, 2021.

  1. Ruffles

    Ruffles Member

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    Edit - Mods, if this is in the wrong place, please move.

    Hi everyone. Normally, we plan for 80% utilization for a given circuit. If you have a 40A circuit, you can charge at 32A for example. 50A can charge at 40A, and 60A can charge at 48A. You get the idea.

    I have a dedicated 60A circuit running 5 feet with #6 wire. It can easily handle the max charge rate of my model Y at 48A. This issues is that I have a 50A 14-50 plug in line.

    Now, I know to pass code, I can swap the 60A breaker for a 50A and the problem is solved. This is what I would do if I was selling the house or had any concern of anyone plugging in a load greater than 50A. Since I'm the only one using it and I know they only load will ever be my car and it tops out at 48A and the plug is rated at 50A, do you think its OK to leave it there?

    I have a Tesla Wall connector and it is currently set to charge at 40A and I'm wondering about cranking it up to 48A. Thoughts?
     
  2. Rocky_H

    Rocky_H Well-Known Member

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    No.
    1. It is a code violation
    2. Sure, you say if/when you sell the house, you'll change it. What if you die suddenly, and the house gets sold without a chance for you to change that? Then there is a dangerous, unsafe, code violating outlet left there to catch someone else.
    3. So it's a wall connector? You added a pigtail cord with a 14-50 plug on it, in violation of the manufacturer's installation instructions? Another code violation.
    4. The ratings of the outlets are I think about the same as the wiring. 50A for short term cycling loads, not for long term permanent ones.
    5. Cord and plug is yet another set of not tight touching contacts, (unlike hardwiring) which is yet another place where things can get loose and have a not good connection, which can become resistive and a hot spot and a fire risk. That is exactly the place where I WOULD NOT recommend trying to push the current extra high.
     
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  3. GregPC

    GregPC Member

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    I would simply change out the breaker to a 60 amp. You already have the correct gauge wire - #6. Also, not sure if your Tesla wall connector will run at 48 amps with a 50 amp breaker. In any case, if you want to crank it up to 48 amps, be safe and follow the specs.
     
  4. brkaus

    brkaus Well-Known Member

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    What @Rocky_H said. Don’t do it. It’s just not worth it.

    You are asking about pushing the weakest link in the chain.
     
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  5. GregPC

    GregPC Member

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    Okay. Sorry, I misunderstood your question. Please ignore my response.
     
  6. Black306

    Black306 Member

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    Do you really need an additional 8A of charging capacity?

    If no, leave it alone.

    If yes, add a 60A breaker and hardwire the HPWC.
     
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  7. iluvmacs

    iluvmacs Member

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    @Rocky_H nailed it as usual. Code violation for sure. You have to think about receptacle ratings the same as wire ratings in terms of what circuit load they can serve. A 50A receptacle is only good for 40A charging, and no more.
     
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  8. Ruffles

    Ruffles Member

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    Thanks for the feedback. I guess its not worth getting 8 more amps. I haven't seen anything in the manual about the pigtail. In fact, a plug like that serves as a disconnect which code requires in some placed. I think I'll just swap the breaker.
     
  9. GtiMart

    GtiMart Member

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    In addition to all that was said, which I agree with (e.g. don't do it), I thought the mobile connector with the 14-50 plug was limited to pulling 32A anyway.
     
  10. jmaddr

    jmaddr Member

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    Forget about the code violations, think about the danger of overheating a receptacle designed only for spikes to 50A. Think fire and danger to life.
    If you do have the wall connector, hardwire that beast and be safe and code compliant at 48a continuous, 60a breaker. When you do sell the place, replace with a 14-50 and 50a breaker.
     
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  11. Ruffles

    Ruffles Member

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    What I wasn't sure about is if the 80% rule applies to downstream components like plugs. It makes sense that it does. Thanks.
     
  12. MD-2000

    MD-2000 Member

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    #12 MD-2000, Feb 18, 2021
    Last edited: Feb 18, 2021
    NEMA 14-60P to 14-50R, 60A to 50A RV Adapter – EVSE Adapters

    This claims to be good for a 60A plug and 50A continuous for a NEMA14-50 socket.
    I can't read the fine print on the plug in the pic, whether it is UL approved for the USA. The "Contact us" has a USA address so the implication is that it's legal approved. YMMV.

    What I did for my Gen2 charger was put a power cord on it with a NEMA 14-50 plug, so I could use the charger (limited to 40A) or the mobile charger (Max 32A). Can you not find a power cord and plug to attach your charger to plug into a 60A socket?

    (You have a charger that's good for 48A? What sort of charger?)
     
  13. Rocky_H

    Rocky_H Well-Known Member

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    #13 Rocky_H, Feb 18, 2021
    Last edited: Feb 18, 2021
    Ugh. I love EVSEAdapters, but that is really irresponsible of them to suggest that it can be used for 50A continuous. Since it has a 14-50 receptacle on one end, you really shouldn't be overdrawing it like that, which is what continuous 50A would be doing. Even IF you were to allow that this is plugging into a 60A outlet type, continuous loads STILL should not be above 48A for that!!

    And he doesn't have a 14-60 receptacle in the wall anyway. And this would be worse relating to my point 5 above if this were to go from a 14-60 outlet in the wall, through this adapter pigtail, to his attached cord, and into his wall connector. That is getting even more spring tension plug connections, for even more weak points in the chain. Not good.

    Just being in the USA certainly doesn't imply that it's UL approved, and I would doubt that something like this is. They make a lot of other adapter cables that in no way could ever be UL approved.

    He already explained all that. He has a wall connector that has a separate 14-50 cord attached.
     
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  14. Rice&Curry

    Rice&Curry Member

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    you need to keep in mind that in case of any power related fire how the insurance company will deal with the incident. I was advised to get my installation inspected by the city for meeting city code to be on the safe side in case of any fire.
     
  15. Ruffles

    Ruffles Member

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    This is what my install looks like. I swapped out the 60A for a 50A breaker tonight and will leave the Wall connector set to 40A. You can ignore the mess of wires at the bottom of the panel box. That will connect to a separate 20A breaker to run a line to my workshop but I wanted to get everything into the panel box at the same time as I was working on the EVSE.
     

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  16. MD-2000

    MD-2000 Member

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    Good idea - 40A, 48A - what's the difference? My 40A charges my 3 at 59km/hr (39mi/hr) which means I could go from 0 to 100% at just over 8 hours, theoretically. In real life, going to 80% it's a rare day (overnight) when I need more than 4 hours, and usually only 2 or 3. (More in winter) I have set charging to start at 1AM and I don't recall ever interrupting charging to leave.

    And If I come home and am worried about an evening trip, I can add a bit for an hour or two. If I could do 48A then I'd maybe charge about 12km/hr more. (8mi/hr). Hardly matters. The biggest change in driving mindset is starting each day with a "full tank".

    Yeah, thanks - that's why my question. I'm surprised it's legal to sell (or import) electrical devices that don't have the certification, but then you're talking about a country where one state's whole electrical system can't even handle the snowstorms that happen every 10 years.
     
  17. Rocky_H

    Rocky_H Well-Known Member

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    Well, it doesn't seem that unusual that a lot of products are sold that are "Use at your own risk", but that's what the certification is there for. They can't announce that it has it if it doesn't have it. That is proof that it has been checked and tested to certain standards, and people might pay more for certain types of products that do have that certification.

    But we're kind of in a niche of products that just can't be UL certified. Adapter pigtails that make all kinds of things fit into other things they weren't intended for is not something that is going to be approved, but it's the kind of thing we do sometimes need in the EV world with some places lacking enough "official" type of charging infrastructure. And being able to buy really well built ones from EVSEAdapters is a hell of a lot better than DIY.
     
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  18. leonar40

    leonar40 Member

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    Why would you say this is a violation? My wall charger came with a 14-50 plug on it from the factory. You can order it with or without.
     
  19. Rocky_H

    Rocky_H Well-Known Member

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    Because people have been DIY adding cords to them in violation of the install instructions for many years. That's what I thought was going on with yours.
    OK, I did not know you had gotten one of those. They only sold those for a very short time--less than a year. So that's why I was not expecting that you had one of the official supported ones.
    No, they've been discontinued for quite a while now.
     
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  20. mspisars

    mspisars Active Member

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    Please take a look at Tesla's shop... 14-50 is available right now for $45 Gen 2 NEMA Adapters
     
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