Model 3

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6-50 charging issue

I put in a 240 volt, 50am breaker for use with a 6-50 connector. When plugged in i only get 8 MPH because it reduces the amperage to 8 amps. The screen says there is a connection issue. All of the wiring checks out so it seems that maybe the 6-50 connector I purchased from Tesla is bad. Anyone else every had this problem?


  • So just to be clear you are using the UMC that came with the car with the 6-50 adaptor you bought extra from Tesla. You have in the car set the max charge to 32amps and it starts out at 32 but reduces to 8 is that correct?

    Are there any errors on the screen or in the system log related to charging as it what does it say exactly?

    What amp service do you have in your home?

    What size wire did you use to install the outlet?

    Does anything get warm?
  • I'd also confirm the wires attached to the breaker panel are properly torqued and the wires to the 6-50 receptacle are properly torqued.

    Also, are the wires you used copper (good), or aluminum (not recommended)?
  • Also: The first few times I used the Tesla Mobile Connector, doing the following seemed to make things work better.
    1. Remove the cable from the car and the wall.
    2. Remove the adapter. Then.. REALLY jam the adapter onto its socket, no ifs, buts, or maybes. (You want good contact..)
    3. Plug the adapter end into your 6-50 socket in the wall.
    Pause 10.
    4. Plug the Tesla cable end into the car.
    If you're still getting problems:
    a. Problem with the TMC. It's new, some do die.
    b. Problems with the car. It's new, it's the AC connections inside the car, well, maybe?
    Assuming that the 1-2-3-4 above doesn't fix things, then:
    1. Take the whole business to the SC and have them get things working either with another TMC (and bring yours with you to check against theirs.) You might have a bad TMC, they can check, and an A vs. B comparison will do the trick. Note that this will pretty quickly isolate whether it's the TMC or the car that's got an issue.
    2. Try _your_ TMC on another Tesla. The SC can do this or, if you happen to know another user with whom you're friendly.

    Being a EE and a techie from many moons ago, a Chief Petty Officer once told me that, "90% of your problems will be with the wires." Over the decades, I've found the man to be correct. Sounds like you've got a new socket in the wall, wiring and all. Let there be one loose screw anywhere and the results you're seeing would be typical. So, depowering the breakers and double-checking every single wire between the breaker and your NEMA6-50 is, as another poster noted, a Good Idea.

    Good luck, and let us know how you're doing and any more clues you've got!
  • Are you sure that your house breaker box and wiring is really capable of 240 volts 50 amps? Have an electrician examine the situation and make a recommendation.
  • What size wire did you use and type, there’s only 3 on a 6-50
  • Wires too thin. The Tesla detects the voltage drop and reduces its charging current.
  • I agree with what others have said. Undersized wires, loose wires, an adapter not fitting well into the UMC body are likely causing a current bottleneck, causing a voltage drop as current ramps up. Nominal voltage before charging begins is one thing, but voltage under charging load is another. What does the charge screen in the car show for voltage when you first plug in and what does it show for voltage as the car ramps up the current? Dropping a handful of volts from say, 240 to 235 is normal as the current ramps to 30 or 40A, but much more and the car will lower its current draw. Do you have nearly 240V to begin with? (Nominal voltage can be 208V if you somehow have 3 phase service - not common in residential, but more possible in some apartment/condo situations.) The car compares initial voltage to voltage under charging load and only accepts a certain percentage drop.
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