Model 3 AMP changes from 48 to 32 apms

[Dans208]

I don't think I'm getting the correct answer. While at the service center, I asked why did my Model 3 drop the Amp chaging from 48 to 32? I have a 60amp breaker where i plug in the cars cord. The tech guy says its because I only have 125 amp service to my house, if I had 200amp service, then car would charge at 48amps...This seems odd considering other appliances dont drop the amps when plugged in. If this is correct, how do I change without rewiring my main panel for 200amps?

 

[TexasEV]

Add this to the list of stupid things Tesla people have said. And if I understand your situation correctly, put your electrician on that list of stupid things people have done. When you use the UMC, the most the car will draw is 32A. You can only get 48A if you have a Wall Connector on a 60A or greater circuit. But when you say “plug in the car’s cord” I assume you’re using the UMC and NEMA 14-50 outlet. This should be on a 50A breaker (or you can use 40A, but not recommended for reasons that aren’t relevant here). You can NOT use a 60A breaker for a 14-50 outlet. This is dangerous. Your electrician should know better.

Your issue has absolutely nothing to do with the electrical service to your house.

 

[Rocky_H]

While at the service center, I asked why did my Model 3 drop the Amp chaging from 48 to 32?

There are two pieces of equipment that have various limits to them. As an analogy, you could look at it as a limit of how fast your car can go, and the road having an allowed speed limit. Either could be the more restrictive, depending on what the numbers are. The onboard charger in the car can receive up to 48A, so that is one limit. But the mobile charge cable has a maximum limit of only 32A that it can provide, no matter what it is plugged into. So the charge cable is the limiting factor here. If you were using a wall connector on a really high power circuit, it may be able to provide 80A, but your car's 48A charger would be the limiting factor.

I have a 60amp breaker where i plug in the cars cord.

Holy cow, something is really wrong with that. 60A outlet types do exist, but since Tesla doesn't make any adapters to 60A outlet types, I know that's not what you're plugging into. You probably have a 14-50 outlet, which must be no more than a 50A circuit. Putting that on a 60A circuit is an obvious and blatant violation of electric code.

The tech guy says its because I only have 125 amp service to my house, if I had 200amp service, then car would charge at 48amps...

Ha ha ha!! Wow. Yeah, that is really wrong and dumb. There's nothing that can sense all the way upstream what your main electrical service is.

 

[Nakid]

I thought that the Tesla Wall Charger was capable of having a 60 amp breaker. I’m waiting on mine now. I’d prefer to charger faster than 28mi/hr.

 

[TexasEV]

I thought that the Tesla Wall Charger was capable of having a 60 amp breaker. I’m waiting on mine now. I’d prefer to charger faster than 28mi/hr.

This thread is about the UMC, not the Wall Connector. (And it’s not the Wall Charger— the charger is in the car).

 

[Reid]

None of this makes sense. There's no 60a plug. The car can't detect what service your house has. The UMC doesn't support that much current. And so on.

Best guess is you had an electrician install a 60a breaker AND a HPWC (not described in your original comment) but the electrician only set the jumper on the HPWC for 32a because they did load calcs on your house's appliances and your main panel can't support 60a for your car, for the HPWC to be jumpered to 48a).
But in that case they shouldn't have put in a 60a breaker, should be against code to do so.

 

[eprosenx]

But in that case they shouldn't have put in a 60a breaker, should be against code to do so.

Actually, unlike the 14-50 example, for the Wall Connector it is fine to install 60a capable wire and a 60a breaker but then to set it down to a lower setting than the max allowed (48a on a 60a circuit). The rotary dial dictates the value you use in the load calculations.

Nothing unsafe about over provisioning the circuit a wall connector is attached to as long as you don’t exceed a 100a breaker with matching wire.

(I agree with everything else you said btw)

 

[cwerdna]

To elaborate further since I think the OP's confused, OP should look at the diagram I grabbed from MNL posted by planet4ever and Three Things Determine EV Charge Time.

There's the on-board charger that dictates the maximum vehicle acceptance rate over AC charging.

For AC charging (L1 or L2 over J1772 or from a Tesla mobile or wall connector), there's an EVSE, and it has a max delivery rate. Model 3 long range has a 48 amp OBC. Model 3 mid-range has a 32 amp OBC. Model S/X/3 Gen 2 Mobile Connector Bundle is only capable of 32 amp output. J1772 EVSEs and these mobile and wall connectors are EVSEs, NOT chargers.

Tesla wall connector has an adjustable max delivery rate that should be set appropriately depending on the circuit its attached to. Was DIP switches on older ones and a dial on newer ones.