Charging Model 3 via HPWC - "Voltage Too High"

[Fiver]

It's a transformer thing. Residential is 120v/240v Single phase center tap. The transformer primary is connected between two of the phases, and the secondary is center tapped, and produces 240V. This gives you two 120V legs, 180 degrees apart.

Industrial/Commercial run three phase (correction have 3 phase run to them), so you get 120v/208v (or 277/480)

Transformers aren't cheap, so as the old adage goes "Run what you brung". If you got 208, run 208 unless you NEED something else.

 

[yuhong]

So you run a three phase transformer to 120V/208V because it is useful for 120V outlets (unlike a 277V to 240V single phase step down transformer) even though it is more expensive, right?

 

[EfficientWatts]

I am having the same problem with 277 charging at work. It is a Tesla destination charging that is listed on the Tesla website. This happened to me over a month and half ago.

Just wondering, before the 3 aborts charging what does the car read voltage wise? And when s/x is charging what does it read?

FWIW someone posted on the model 3 forum that a model 3 was charging @ 256 V so the limit is higher than 250V but lower than 277V. Fastest level 2 charge in the world!

 

[MP3Mike]

Just wondering, before the 3 aborts charging what does the car read voltage wise? And when s/x is charging what does it read?

FWIW someone posted on the model 3 forum that a model 3 was charging @ 256 V so the limit is higher than 250V but lower than 277V. Fastest level 2 charge in the world!

That information is all in his first post. The Model 3 read 278 when trying to start the charge, the Model S read 275 volts while charging at 42 amps.

 

[EfficientWatts]

That information is all in his first post. The Model 3 read 278 when trying to start the charge, the Model S read 275 volts while charging at 42 amps.

I was asking about cellogig's experience, which is different from the OP, so as to gather another data point.

 

[miimura]

It's a transformer thing. Residential is 120v/240v Single phase center tap. The transformer primary is connected between two of the phases, and the secondary is center tapped, and produces 240V. This gives you two 120V legs, 180 degrees apart.

Industrial/Commercial run three phase (correction have 3 phase run to them), so you get 120v/208v (or 277/480)

Transformers aren't cheap, so as the old adage goes "Run what you brung". If you got 208, run 208 unless you NEED something else.

I was talking about using a Buck-Boost transformer to drop the existing 277V service to 240V L-N. A Hammond Q003ESCF appears that it would do the job for a 100A HPWC. See the Catalog. Specified as HV=272 LV=240 Connection Diagram #4. So, it would run a little bit high at 244VAC. The price is under $500 at Allied Electronics.

 

[sammyfan711]

I charged my model 3 at 256 volts last night, I wonder if 260 volts is the cutoff

 

[yuhong]

I charged my model 3 at 256 volts last night, I wonder if 260 volts is the cutoff

The normal cutoff would be around 265V.

 

[cellogig]

Just wondering, before the 3 aborts charging what does the car read voltage wise? And when s/x is charging what does it read?

FWIW someone posted on the model 3 forum that a model 3 was charging @ 256 V so the limit is higher than 250V but lower than 277V. Fastest level 2 charge in the world!

Funny you should ask this, I was going to try my wife’s model x tonight to see what the voltage reads on the screen.
When I tried my model 3 (several times) over a month ago the voltage it would read 2v and you could see the mi/hr , 0/0 a and the 0 mi on my screen trying to take the charge and then eventually shut everything down. The charge port would turn red.

The sad thing is as I stated earlier this is a Tesla destination charger listed at teslas website.

I had Tesla support on the line with me while this was happening. They have it in their logs. I was told nothing at the time why this was happening. I have pushed the issue with Tesla and today was the first answer I got why. On board voltage controller is rated up to 250 v in the model 3. The Tesla charger at my workplace is hpwc 277

 

[EfficientWatts]

I had Tesla support on the line with me while this was happening. They have it in their logs. I was told nothing at the time why this was happening. I have pushed the issue with Tesla and today was the first answer I got why. On board voltage controller is rated up to 250 v in the model 3. The Tesla charger at my workplace is hpwc 277

Something tells me 250V is what the Model 3 is spec-ed at and thus the value quoted by support, not the actual full range. As we saw in that one screenshot we do have that one model 3 charging at 256V.

It is a given that there has to be some safety margin to allow for an over voltage scenario.

 

[cellogig]

Just wondering, before the 3 aborts charging what does the car read voltage wise? And when s/x is charging what does it read?

FWIW someone posted on the model 3 forum that a model 3 was charging @ 256 V so the limit is higher than 250V but lower than 277V. Fastest level 2 charge in the world!

Here is the model s being charged at a 277v Hwpc. These are the readings on charging

 

[EfficientWatts]

Here is the model s being charged at a 277v Hwpc. These are the readings on charging

View attachment 301213

282 is quite high. Still in spec for a 277V line, but to properly support 277V I believe you would need +10%, which is ~305V. On the other hand +10% for 240V is 264V.

I guess if the model 3 wanted to cut costs, they might have used components that are only safely rated for 240V + margin. Then again if they're leveraging the same supply chain as the model s/x "277V" may still be there though Model 3 may be high enough volume to use its own charging components.

I wonder if the voltage was lower if the model 3 would charge.

It is interesting that the max current is limited to a weird number.

 

[miimura]

It is interesting that the max current is limited to a weird number.

240V * 48A = 11,520W
11,520W / 282V = 40.85A

There's your 41 amps. The 48A charger also imposes a limit of 11.5kW.

 

[yuhong]

Something tells me 250V is what the Model 3 is spec-ed at and thus the value quoted by support, not the actual full range. As we saw in that one screenshot we do have that one model 3 charging at 256V.

It is a given that there has to be some safety margin to allow for an over voltage scenario.

On the other hand, not many other EV vendors supports 277V charging, and Model 3 will be produced in more volume than Model S/X was.

 

[cellogig]

282 is quite high. Still in spec for a 277V line, but to properly support 277V I believe you would need +10%, which is ~305V. On the other hand +10% for 240V is 264V.

I guess if the model 3 wanted to cut costs, they might have used components that are only safely rated for 240V + margin. Then again if they're leveraging the same supply chain as the model s/x "277V" may still be there though Model 3 may be high enough volume to use its own charging components.

I wonder if the voltage was lower if the model 3 would charge.

It is interesting that the max current is limited to a weird number.

If the voltage was lower yes it would. I went to another Tesla destination charging station and it was fine. Different set
up but worked just fine. Again the volts is the problem. I was told by a rep that the newer model x and s will have the same setup as the 3 regarding the voltage controller

I will keep you posted. Thank you for explaining and taking the time. This thread and posters have been helpful thank you again

 

[EfficientWatts]

Someone needs to try to charge on something in the range of 256-277V (lower 270s/upper 260s would be especially interesting).

 

[Fiver]

I was told by a rep that the newer model x and s will have the same setup as the 3 regarding the voltage controller.

This is interesting.

 

[cellogig]

This is interesting.

Remember though it was a service Tesla rep in Utah who was helping me with blue tooth connectivity. So I asked him the question about issues of charging with my model 3

 

[EfficientWatts]

Remember though it was a service Tesla rep in Utah who was helping me with blue tooth connectivity. So I asked him the question about issues of charging with my model 3

Ran into this post via Reddit

Tesla Model 3 - NextGen Battery - EVTV Motor Verks

The guy points out how the AC charger is completely different from the Model S/X (it's a bit smaller too which is why it's 48A max besides cost reasons), more importantly he says this:

The combined charger/dc-dc converter is a thorough MARVEL inside. We will be looking more closely at this in the future but it again has NO apparent relationship to any previous Tesla charge circuitry, and they squeeze 10kW of charger into a remarkably small and cool running package.

...

And no evidence of a SINGLE part in this assembly that has ever been near a Model S. Entirely different contactors. Of course a different charger/dc-dc converter which is now a “power conversion unit” and the BMS board is now entirely different and referred to as a “high voltage controller”.

So that could partially explain why the Model 3 behavior may be different from the S and X.

However I still wonder if it could still charge 277V and that this is a software limitation, but at the very least the above does explain why it wouldn't work out the door.

 

[yuhong]

Thinking about it, I wonder if the work to make 120V charging more efficient in Tesla Model 3 don't help.