Model X

Car charger plug melted

edited November -1 in Model X
Anybody have their plug that game with the car melt?
I just walked into the garage and smelled melted plastic. Yes - it was the charger plug - melted - still plugged in.
I saw a recall in Fall 2016 for adapters that melted - but this was he regular plug.


  • edited August 2018
  • edited August 2018
    That's scary. I'm glad it didn't result in a fire.
    What were you plugged in to in the garage? A NEMA 14-50 socket?
    Was it the connector at the car that melted (or at your wall socket)? Did it damage the car's charge port?
  • edited November 2018
    Mine just melted. No problems charging at home with a NEMA 14-50 on a 50 amp breaker for over 1 yr. Last Friday the 200 amp whole house breaker blew. Very scary stuff for non-electrician to have the 200 amp panel breaker blow in front of you. thank god for safety breakers.
    After investigating I found that the Leviton outlet was burnt out and the 50 amp breaker was now weak (it kept tripping). The Tesla recommended contractor (who was great-knowledgeable and professional) replace the outlet and breaker under warranty. He said the that the Tesla recommended (and car default) charging at 48 amps on a 50 amp breaker is not a good idea. If we routinely charge on a NEMA 14-50/ 50 amp outlet we should only be charging at 40 amps (80%). you can manually set this on the car and it will remember. It takes a little longer to charge but it avoids the heat build up and outlet/breaker failure. Just a suggestion.
  • edited November 2018
    @tjhlaw, it's more than just a suggestion... it's code. A breaker must be rated at 125% of the maximum continuous current. 48 amp charging requires a 60 amp breaker.
    I'm curious where you read a Tesla recommendation to run 48 amps on a 50 amp circuit. All the HPWC and UMC manual documentation I have from 2016 is consistently clear on the 125% rule. If you have a document that states otherwise, you should bring it to Tesla's attention... it's a dangerous mistake.
  • edited November 2018
    Glad nothing major happened. - Just shaking my head.

    Do not "cheat" the standards/code!!

    Rule #1 - you will ONLY charge at 80% capacity of the breaker. Not 81%, not 99% - EIGHTY PERCENT.

    40 Amp breaker means you charge at 32 AMPS
    50 Amp breaker means you charge at 40 AMPS
    90 Amp Breaker means you charge at 72 AMPS

    Follow the rules/laws! They're put in place for your protection.
  • edited November 2018
    This is incorrect. The UMC Gen1 doesn't allow more than 40 Amps with a NEMA 14-50 plug! You cannot charge at 48 Amps... The UMC Gen2 is even lower, you're limited to 32 Amps even with the 14-50 plug...

    How on earth did you manage to get 48 Amps??
  • edited November -1
    Passion2Fly - I was going to say the exact same thing :) My car will NOT let me go above 40amps on a 50amp breaker. I installed the Wall Charger and left it on a 50amp breaker as that is what I had at first. My car would NOT charge at 48 amps - it would not let me adjust above 40 amps - it knew that. I then got a 60amp breaker and now lets me go up to the full 48 amps.

    So there is no way that you were using a NEMA 14-50 and the car was letting you charge at 48 amps (well I shouldn't say no way...but you would have to have some major bug to your car that would have let you do that.)
  • edited November 2018
    I just checked the installation specs from Tesla for the NEMA 14-50 again. It says that the minimum circuit breaker should be a 50 amp breaker. I probably should have use a 60 amp, but how would I know? I'm a lawyer not an engineer.

    I have a gen 1 charging cord that supposed to charge up 40 amp. The car was set to charge at 48 amps, but that was by default I never noticed it or changed it.

    From what I can tell the car was drawing or trying to draw too many amps (48) through the mobile connector against the 50 amp breaker.

    All I know is that I used a Tesla recommended contractor to install the outlet, a Tesla mobile connector that came with the car and I never adjuster the amps for charging (hell, I didn't even know I could adjust the amps until after this incident). This post is just my attempt to warn others to watch for this. It scared the crap out of me.
  • edited November 2018
    tjhlaw - are you sure that your car when you plugged it in to the NEMA 14-50 actually said 48amps? I am not trying to doubt you - it is just that the car itself is supposed to recognize the connection and know the max it will allow. As in my illustration with my car - when I use the NEMA 14-50 and Gen 1 cable, it physically will not let you select anything about 40 amps. A 60 amp breaker with a NEMA 14-50 still won't help - the outlet is not rated for the 48 amps either.

    I would do a test with a 14-50 outlet if you can. Plug it in and after doing that, check to see what the set amps the car should be 40, and no possible way to go up from there. If for some reason your car is allowing more - there is an issue with your car and should call Tesla to address it.
  • edited November 2018
    In fact, I should say - you are NOT supposed to use a 60 amp breaker with a 14-50 outlet. That is not to code. The outlet can only handle max of 50 amps but if for some reason, more flows through it, the breaker will not trip and thus a fire could occur at the outlet. So no, you should NOT have used a 60 amp breaker with a NEMA 14-50 - not to code and would not pass inspection - if doing yourself and not getting inspected, you are running a huge risk of fire and even insurance not covering it :)
  • edited November 2018
    100% agree with @burdogg.

    If it’s true that the car selected 48 Amps, it’s possible that there is a software glitch or the Gen1 UMC has failed for some reason... try plugging in again and check the screen. If it says 48 amps DO NOT use the UMC! It might be damaged... order a new one or check warranty to see if you can get it replaced for free...
  • edited November 2018
    I’m sorry... you just mentioned that your UMC melted, so it’s unusable now...
    I strongly suggest buying a Gen2 UMC. It is slower charging at 32 amps instead of 40 amps but it has temperature sensors in both the 14-50 plug and the car connector. As soon as the temperature rises, it will drop the charging current and will alert you via the phone app...
  • edited November 2018
    Nobody has mentioned yet that the Tesla charger can NOT detect the breaker that is being used. The charge cable detects the plug (the Tesla plug not the outlet) that is connected to the adapter. If that is plugged into an extension cord or other outlet/adapter the unit has no way of knowing.

    An example that I have seen used is a short extension cord with a 110 volt 15 amp plug and a 110 volt 20 amp socket to be plugged into a 12 gauge wired circuit with a 20 amp breaker (very few 20 amp outlets are installed even in 20 amp circuits. and used with the Tesla 110 volt 20 amp adapter plug. The resulting charge is then at 16 amps instead of 12 amps.
  • edited November 2018
    Yes, indeed. The UMC detects the plug not the wire gauge or the circuit breaker... that’s why never use adapters and/or extension cords. By they way, I never use the 5-15 plug. It’s pretty much useless for the MX... maybe the M3 gets more miles out of a 15 amps outlet...
  • edited November 2018
    Also the 14-50 adapter on the UMC Gen-1 (partly gray) are thermally protected. Very early 14-50 adapters (all black) are not, and were recalled in 2014. At the same time, tesla upgraded the software to reduce the current if there is too much voltage drop under load (indicating poor wiring).

    I don't know what type of receptacle you have, but I'd also install a industrial 14-50 receptacle. Most of the ones you get at the local hardware stores are residential grade, and are really intended for stoves where it is unplugged once or twice in it's life, This lists the industrial versions available for all the outlets you may use: Note these can be expensive!
  • edited November -1
    It's far better to just install a Tesla Wall connector to avoid all of these problems and all of the resultant confusion as evidenced in this thread, which has lots of piecemeal facts, individually true, that don't add up to a consistent nor accurate story.

    TeslaTap's wiring guide is a good start if you want to learn the in-n-outs yourself. Or just have an electrician install a Tesla Wall Connector on a 30 to 60 amp circuit, for a reasonably priced, SAFE and quite effective charging solution.
  • edited May 2019
  • edited July 2019
    I had problem with my J1772 adaptor. The car stop to charge one night and when I got into the car, the charge was essentially the same as the night before.

    Next evening, I made sure it was properly charging and the following evening I got a message on the phone that the charge has been interrupted. So I went to check the connection and it seems a bit loose but it was finally charging at full power (30 amps).

    Next morning, when I tried to remove the adaptor, it stick to the cable and I need to pull strong to separate the adaptor from the cable and then notice that the adaptor has melt a bit (at least my car was charged). The 2 pins are somewhat burned (black on the end).
  • edited July 2019
    @philippem - Which end? If the adapter end that connect to the J1772/L2 cable, it's likely the cable's connector is worn or your J1772 adapter is worn and causing a poor connection. If it works at a different location, then the cable/connector is likely damaged. Some L2 locations get used a lot and can wear out.
  • My plug from the HWPC was connected to my car and when I pulled it out one of the terminals inside the plug has melted pretty badly. Didn't small the burning plastic but it's definitely not going to work anymore. I was told to email Tesla at [email protected] for support but haven't heard anything back yet. Kind of important since my only other option is the 110v charging cable and it's -20C here right now so i need the charge!
  • edited January 16
    I love how lilbean and bighorn are not touching this thread with a ten foot pole. Probably because that pole is lodged so far up their assiduous lack of truth telling.
  • edited November -1
    Let me impersonate them for now:
    “Oh but your car is still working right ? Are you suggesting that all the electrons in the universe have stopped spinning about their orbitals? Hmmmm”
  • edited January 17
    More flags for mr obvious troll there.
  • edited January 17
    Is this the car plug, or do you have the wall plug HPWC?
Sign In or Register to comment.