Charging at 32A? Get 25% faster charging.

[mknox]

There's no reason at all - unless you've got some links - to suspect that the information I relayed isn't the actual reason... that in Canada, 40A circuits are common on NEMA 14-50 outlets and 80% of 40 = 32A is the reason we're restricted to 32A. Nothing to do with 70% for "continuous loads" (70% * 50 = 35, not 32 and Telsa engineers are perfectly adept at arithmetic) and nothing to do with fancy Canadian electrons that are hotter than American ones.

I don't believe I said anything about 70%. In the US and Canada, it is permissible to install a NEMA 14-50 on a 40 amp circuit which, by both US and Canadian code limits "continuous loads" to 80% of that rating. "Continuous loads" are defined in US and Canadian codes and include EV charging. I have relatives in the US with electric stoves hooked up the same way we do here in Canada (on 14-50's with 40 amp breakers). But they are no more or less common in either country since both the NEC and CEC allow this configuration.

As I said, it came down to a certification issue in Ontario. The original UMCs were not CSA or UL-C listed. Now they are. It was a condition of the testing and listing that resulted in this requirement.

I suggest you refer to Section 86 of the Ontario Electricity Safety Code for further information on electric vehicle charging systems.

Then I suspect you have a specific defect somewhere unrelated to any of this.

The magic comes down to a resistor on the pilot pin.. that's all. The car controls the charge rate, but it does this based on the "signal" it receives by way of measuring that resistor. New Canadian adapters "tell" it to charge at 32A while American ones "tell" it to charge at 40A.

It seems odd then that Tesla would have gone to the expense of sending me a whole new UMC set and new adapter. Prior to this, there were some overheating situations that led to a recall of the original 40 amp adapter. Then, they just sent me a new 40 amp adapter that had a thermal fuse in it, not a whole new cable set. I checked again, and my original and updated 40 amp adapters will not work on the new UMC that Tesla sent me. They both still work on the old UMC cable.

For me, this all transpired a few years ago. Maybe "newer" UMCs are able to recognize both 40 and 32 amp adapters by their internal resistors.

 

[racer26]

I don't believe I said anything about 70%. In the US and Canada, it is permissible to install a NEMA 14-50 on a 40 amp circuit which, by both US and Canadian code limits "continuous loads" to 80% of that rating. "Continuous loads" are defined in US and Canadian codes and include EV charging. I have relatives in the US with electric stoves hooked up the same way we do here in Canada (on 14-50's with 40 amp breakers). But they are no more or less common in either country since both the NEC and CEC allow this configuration.

As I said, it came down to a certification issue in Ontario. The original UMCs were not CSA or UL-C listed. Now they are. It was a condition of the testing and listing that resulted in this requirement.

I suggest you refer to Section 86 of the Ontario Electricity Safety Code for further information on electric vehicle charging systems.



It seems odd then that Tesla would have gone to the expense of sending me a whole new UMC set and new adapter. Prior to this, there were some overheating situations that led to a recall of the original 40 amp adapter. Then, they just sent me a new 40 amp adapter that had a thermal fuse in it, not a whole new cable set. I checked again, and my original and updated 40 amp adapters will not work on the new UMC that Tesla sent me. They both still work on the old UMC cable.

For me, this all transpired a few years ago. Maybe "newer" UMCs are able to recognize both 40 and 32 amp adapters by their internal resistors.

@mknox
I think it actually is a bit stranger still.

I think the firmware in the UMC itself has something to do with it. My theory is that the UMC queries the resistor in the adapter, and IDs the adapter its connected to, and then reports on to the car via the J1772 protocols what it can provide.

My car (bought CPO from Tesla in April 2017) has the Canadian 32A 14-50 adapter, and yet charges at 40A with it.

Tesla service guys looked at it and verified it was the proper Canadian one twice and passed it through their check where they swapped people out (or at least, my service documentation says they did).

I believe what's happened, is that I have gotten an original UMC, with the new adapter. The original UMCs firmware doesn't know about the 32A version of the adapter, and defaults to assuming an unrecognized adapter can push the full 40A. Thus, the new UMCs were sent out so that they could read the 32A adapter and limit correctly.

 

[Cosmacelf]

You can check with an ohm meter if the resistance value of the old and new adapters is the same or different...

 

[racer26]

You can check with an ohm meter if the resistance value of the old and new adapters is the same or different...

We know they are - the original 14-50 adapter (the one they still ship with US cars) is distinct as far as the UMC is concerned from the Canadian 32A 14-50 adapter.

 

[mknox]

I think the firmware in the UMC itself has something to do with it. My theory is that the UMC queries the resistor in the adapter, and IDs the adapter its connected to, and then reports on to the car via the J1772 protocols what it can provide.

My car (bought CPO from Tesla in April 2017) has the Canadian 32A 14-50 adapter, and yet charges at 40A with it.

I believe what's happened, is that I have gotten an original UMC, with the new adapter. The original UMCs firmware doesn't know about the 32A version of the adapter, and defaults to assuming an unrecognized adapter can push the full 40A. Thus, the new UMCs were sent out so that they could read the 32A adapter and limit correctly.

I think you may be on to something wrt firmware. I know for a fact that the CHAdeMO adapter can have its firmware updated and it would make sense that the UMC could too.

But you say you got the "original" UMC with your CPO car. What year is the car? Your "original" UMC may be different (or have different firmware) than my "original" UMC which dates to February 2013.

Right now, I have 2 UMC cables and 3 14-50 adapters: the original 40 amp unit, the "new" 40 anp unit with the thermal fuse and the "newer" 32 amp one. The UMC that came with the car will work with the 40 amp adapters. The new UMC they sent me will not.

I think it's fair to say that not everyone in Canada with the 32 amp set will be able to use the US 40 amp adapter. Depends on the version/firmware/date of manufacture of the UMC they have.

 

[fsch]

The UMC that came with the car will work with the 40 amp adapters. The new UMC they sent me will not.

In my case, the new UMC Tesla send me still works at 40 A with the old adaptor of the original UMC. I use it every week.

 

[mknox]

In my case, the new UMC Tesla send me still works at 40 A with the old adaptor of the original UMC. I use it every week.

There must have been a bunch of different UMC sets out at that time with different firmware or whatever. Otherwise it makes no sense that Tesla would go the expense and hassle of sending out complete UMC sets when a simple 32 adapter would have done the trick.

EDIT: I may have got what you said backwards. Not sure why, but my NEW UMC will not work with the OLD 40 amp adapter for some reason.

 

[dasRad]

When Tesla recalled the original (40A) 15-40 adapters, ours was heat fused to the UMC so they replaced both the adapter and the UMC. The replacement set has been running at 40A since then and is much cooler.

 

[fsch]

Should buy a machine to kick myself in the ass, as we say in Quebec: Three weeks ago, I went to the service center for the 4 years/160 000 km inspection and forgot to remove my UMC from the trunk (with the original 40A adaptor). The next time I had to used it, this weekend, I discovered that they changed the whole thing (for free, and they didn't told me, so it went under the radar when I picked up the car). But it was indeed indicated on the bill. So now I'm stock with the brand new 32A version.

 

[brkaus]

Should buy a machine to kick myself in the ass, as we say in Quebec: Three weeks ago, I went to the service center for the 4 years/160 000 km inspection and forgot to remove my UMC from the trunk (with the original 40A adaptor). The next time I had to used it, this weekend, I discovered that they changed the whole thing (for free, and they didn't told me, so it went under the radar when I picked up the car). But it was indeed indicated on the bill. So now I'm stock with the brand new 32A version.

That's rude.

 

[mknox]

Should buy a machine to kick myself in the ass, as we say in Quebec: Three weeks ago, I went to the service center for the 4 years/160 000 km inspection and forgot to remove my UMC from the trunk (with the original 40A adaptor). The next time I had to used it, this weekend, I discovered that they changed the whole thing (for free, and they didn't told me, so it went under the radar when I picked up the car). But it was indeed indicated on the bill. So now I'm stock with the brand new 32A version.

First thing I did was put the new UMC they mailed to me in the car and left the original at home for fear of this exact scenario.

 

[Doug_G]

Yeah I have the UMC that came with the new car, in the car.

But I have another one that works at 40A that I can throw in the frunk if I’m traveling.

 

[fsch]

Should buy a machine to kick myself in the ass, as we say in Quebec: Three weeks ago, I went to the service center for the 4 years/160 000 km inspection and forgot to remove my UMC from the trunk (with the original 40A adaptor). The next time I had to used it, this weekend, I discovered that they changed the whole thing (for free, and they didn't told me, so it went under the radar when I picked up the car). But it was indeed indicated on the bill. So now I'm stock with the brand new 32A version.

I went California a couple of weeks ago and stoped at a Tesla Service Center to purchase a new 40A adaptor. I was not sure if it would work with the new UMC but I thought I would try, and purchase a UMC next time I go to the US if it didn't. When was the time to pay (after the usual ~10 minutes of computing, never understood what takes so much time), there was no way to pay with a credit card that is related to an address outside of the US, and no possibility to pay cash. So finally, the supervisor decided to give it to me on goodwill!

And the 40A adaptor does work well with the UMC exchanged by Tesla. So in the end, I just had this inconvenience for a winter...

 

[sakimano]

I had a 2015 70D wiht the old style, and used to charge at home at 48 km/h connected.

Now I have a late 2015 P90D with the new style, and charge at home at about 34-35km/h.

The car is always finished charging sometime while I'm sleeping. Still annoys me for some reason . Once I forgot to charge and had to go on a long trip and there were no superchargers near my house at that time. I plugged in for 4 hrs to get enough range to reach the first supercharger on my trip. This could have been accompished in 3 hrs had I had the old style adapter.

One thing I noticed when I got the new car was that the UMC cable seemed quite a bit thinner than the old one. Is that all in my head?

 

[mknox]

...there was no way to pay with a credit card that is related to an address outside of the US, and no possibility to pay cash.

This suggests that Tesla is trying to reduce their liability for selling an illegal component (in Canada) by screening cards. I have bought lots of non-electrical Tesla accessories in California and had no issues using my Canadian credit card.