Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Rating on 6-50 UMC Gen 2 Adapter is only 30a rated - why?

This site may earn commission on affiliate links.
I now have my car and I have the connector printed with "30a". I just don't have a 6-50 plug wired up at the moment.

Will have to give that a shot when I get an opportunity! (probably won't be any time soon though since I don't have a convenient place to test).

so you have the C revision of the part? Have you asked Tesla about the discrepancy? The website still says that 6-50 and 14-50 will charge at the same rate.
 
FYI-

I just realized my UMC Gen 2 14-50 adapter that came with the car is *also* labeled a max of 30 amps. I have not tested it yet (but I do have a 14-50 receptacle!). I will test soon.

The part number on this adapter is: 1099344-00-D

My friend who got his Model 3 a month or so before me has a 14-50 adapter labeled 32 amps. It is model 1099344-00-C.

I just called Tesla and asked them to open a case for me. The guy on the phone did think that was pretty weird. I find it hard to believe that this could be a mistake, but it makes me worried that they are going to have to downgrade all the adapters to 30a for some reason (in software). Maybe they have discovered some portion of the UMC Gen 2 can't handle the full 32 amps and so they are going to further derate it in software to 30a?

I will see what they say!
 
  • Helpful
Reactions: autospy
Ok, well I gave Tesla two business days and they did not get back to me so I called them again today (about a different issue) but I bugged them a second time about this issue after waiting for two hours and ten minutes on hold before getting a human. I just sent these pictures to the support rep I spoke with along with this video that CLEARLY shows that something is wrong here.

Tesla clearly advertises the UMC Gen 2 as 32 amp capable on their web site, so I am curious if this is a misprint (though that is HARD to imagine!!!)


P.S. All the folks I have spoken with at Tesla have been great, though just so far not much followup.

6-5014-50.jpg
 
  • Informative
Reactions: hoang51
So I got a call back the other day from Tesla Support about this.

They say that the change from 32a to 30a was intentional, but that the car will still charge at 32a.

They said something about the value printed on there needing to be plus or minus ten percent of actual.

So here is my guess:

The plus or minus 10% is probably intended for things like motors where the manufacturing tolerances are just not that tight. So if you ask for a 32a rating, maybe you have to have it tested to 35.2a as that is the upper bound of the tolerance. Since the Tesla is all electronically controlled they know damned well it is going to always draw pretty much exactly 32a.

So my guess is that Tesla for some reason decided to just ask for a 30a rating, knowing full well that the car would draw 32a, but that is still well within the +10% variance allowed. So perhaps that only requires them to test the UMC to 33a instead of testing all the way to 35.2?

I am not sure, but this is just my conjecture. I am not an expert in UL testing procedures and policies.

At the end of the day, I don't think this is any kind of a risk at all. Though I do wonder: Does this mean for NEC calculation reasons that I only have to do the math on wire and breaker sizing as if it is 30a? As far as I know, this is the "nameplate" for the device.
 
  • Informative
Reactions: hoang51