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Model S - HPWC (High Power Wall Connector)

MorrisonHiker

S 100D 2021.4.12
Mar 8, 2015
9,398
8,543
Colorado
I have a 2014 Model S and a Gen 1 HWPC. I just installed it on a 60A breaker. When I set the dip switches to 60A, the car only charges at 12A. However if I set the dip switches to 50A, the car will charge at the correct rated 40A. Any ideas what is going on here? The HWPC is giving no error lights or anything.
Just to confirm, are you setting the dip switches as shown below?
upload_2021-1-4_14-2-17.png
 

MorrisonHiker

S 100D 2021.4.12
Mar 8, 2015
9,398
8,543
Colorado
Yes sir. Top 2 switches to the right, bottom 2 switches to the left.

For 50A the top 3 remain the same and the bottom switch moved back over to the right. I ran test mode before all this and it didn't give me any errors either.
I don't have a gen 1 wall connector so I can't be of much help. I checked the manual and saw the dip switch settings. If they are correct, then I'm stumped. Maybe @Rocky_H would have some ideas?
 
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scaesare

Well-Known Member
Mar 14, 2013
8,230
13,161
NoVA
I have a 2014 Model S and a Gen 1 HWPC. I just installed it on a 60A breaker. When I set the dip switches to 60A, the car only charges at 12A. However if I set the dip switches to 50A, the car will charge at the correct rated 40A. Any ideas what is going on here? The HWPC is giving no error lights or anything.
Does the car indicate 12/60A or 12/12A?

Also, not that I think it would explain this, but does your car have dual Gen1 chargers or the single later-gen 48A charger?
 

irish26

Member
Dec 10, 2020
40
34
Florida
Does the car indicate 12/60A or 12/12A?

Also, not that I think it would explain this, but does your car have dual Gen1 chargers or the single later-gen 48A charger?

it indicates 12/12A. I do not believe the car has dual chargers. It was not listed on the moroney paperwork.
 

scaesare

Well-Known Member
Mar 14, 2013
8,230
13,161
NoVA
it indicates 12/12A. I do not believe the car has dual chargers. It was not listed on the moroney paperwork.

OK, then you won't get anything more than the 40A the car can use for a 50A circuit anyway.

So you can either:

1) Set the HPWC back to 50A, and forget about it while enjoying the maximum your single charger can give you

or

2) Try to figure out this odd behavior, as the car should use it's max rate (40A) even on an HPWC capable of delivering more.

If you want to try the latter, maybe set the HPWC to test mode as on pg. 11 (dip switches all right) and see if ti passes?
 

tga

Supporting Member
Apr 8, 2014
3,872
2,675
New Hampshire
Ok. So maybe my max is 40A. I just assumed it was 48A

If that is the case, should I switch out my breaker for a 50A breaker? Or is it OK to run the wall connector set to 50A when it’s really on a 60A?
As long as the wire is rated for 60A, a 60A breaker is fine (what wire - gauge/type - did you use?). The breaker is there to protect the wire, not the device at the other end of the wire.
 
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irish26

Member
Dec 10, 2020
40
34
Florida
As long as the wire is rated for 60A, a 60A breaker is fine (what wire - gauge/type - did you use?). The breaker is there to protect the wire, not the device at the other end of the wire.

#6 thhn wire for about a 25’ run. It was an electrician. I did not do the work myself.
 
Last edited:

Rocky_H

Well-Known Member
Feb 19, 2015
5,964
6,887
Boise, ID
I have a 2014 Model S and a Gen 1 HWPC. I just installed it on a 60A breaker. When I set the dip switches to 60A, the car only charges at 12A. However if I set the dip switches to 50A, the car will charge at the correct rated 40A. Any ideas what is going on here? The HWPC is giving no error lights or anything.
This is funny. I got to this thread a few hours ago when this was the last message on here, and already had an idea of what was causing this but got called away to work stuff, so I just now got back to it and see there are more messages.
I don't have a gen 1 wall connector so I can't be of much help. I checked the manual and saw the dip switch settings. If they are correct, then I'm stumped. Maybe @Rocky_H would have some ideas?
And I saw someone used my Bat-signal.
Just to confirm, are you setting the dip switches as shown below?
View attachment 624169
The thing is...there were two versions of the Gen 1 wall connectors, and they used different DIP switch settings, which do explain this behavior!

Here is the link to the first version Gen 1 manual, with part numbers ending in A or B:
https://www.tesla.com/sites/default...l-connector-installation-installation-a-b.pdf
And that's where you DIP switch setting comes from, with the top two right and bottom two left meaning 60A breaker.

But here is the version for the later Gen 1, with part numbers ending in C or D, where they added some more breaker settings, including lower level circuits:
https://www.tesla.com/sites/default...se-wall-connector-installation-manual-c-d.pdf

And in that version of the wall connector, if you have the DIP switches set that way, it's for a 15A circuit, supplying 12A to the car! So @irish26 that seems to be your issue. If you look at the part number, I'll bet you have this type ending in C or D. Now unfortunately, they didn't have a setting for 60A breakers. They had 50 or 80. So with your setup, the 50 is about the best you can do, supplying 40A to the car. It just happens to be a coincidence that the DIP switches for 50A are the same between both versions of the wall connector. They repurposed some of the less common breaker size settings of 60, 70, and 90 to make the settings for lower level circuits.

Dang, this was a fun mystery!
 

JPoldo

Member
Aug 13, 2017
306
137
Boston, MA
Has there been any news on the gen3 WC capable of direct billing to users? Clearly, it requires new software to achieve this functionality, but heard from reliable sources it was coming. This feature would greatly help people who live in apartments & condominiums charge at home. I think many of these prospective EV buyers are sitting on the sideline waiting for home charging.
 

irish26

Member
Dec 10, 2020
40
34
Florida
And in that version of the wall connector, if you have the DIP switches set that way, it's for a 15A circuit, supplying 12A to the car! So @irish26 that seems to be your issue. If you look at the part number, I'll bet you have this type ending in C or D. Now unfortunately, they didn't have a setting for 60A breakers. They had 50 or 80. So with your setup, the 50 is about the best you can do, supplying 40A to the car. It just happens to be a coincidence that the DIP switches for 50A are the same between both versions of the wall connector. They repurposed some of the less common breaker size settings of 60, 70, and 90 to make the settings for lower level circuits.

Dang, this was a fun mystery!

Boom that was it! My part number ends with D. Bummer that they don’t have a 60A setting but oh well. 40A will be just fine for me. Thanks for taking the time to solve this one!
 
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tga

Supporting Member
Apr 8, 2014
3,872
2,675
New Hampshire
#6 thhn wire for about a 25’ run. It was an electrician. I did not do the work myself.
You're good - don't worry about replacing the breaker (not worth the $) - 6ga THHN is good for 60A, since you can use the 75degC column. NM-B (romex) is only good for 50A (since you must use the 60degC column for NM-B). But @Rocky_H solved the mystery (I had completely forgotten about the A/B vs C/D version of the Gen 1)
 
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morrisdl

Member
Dec 4, 2017
305
184
Smith Mt Lake, VA
Does you S have a 2nd onboard charger? If not 40A is the max.
Have you had and eMMC MCU1 problems? Mine would sometimes default down to 12A before it was replaced with the new 64G version
Lastly, maybe it is just a bug in the current S/W that MCU1 Tesla dont negotiate with 60A HWPC.
 
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David29

Supporting Member
Aug 1, 2015
2,170
1,786
DEDHAM, MA
I have a 2014 Model S and a Gen 1 HWPC. I just installed it on a 60A breaker. When I set the dip switches to 60A, the car only charges at 12A. However if I set the dip switches to 50A, the car will charge at the correct rated 40A. Any ideas what is going on here? The HWPC is giving no error lights or anything.
Do you know if you have dual chargers installed? If not, the car will only charge at a maximum of 40 Amps anyway. The 48 amp chargers came later in Model S production. That may (or may not) be an explanation.
 

irish26

Member
Dec 10, 2020
40
34
Florida
Me again. I’m looking at upgrading to MCU2 thanks to the lowered price.

I stumbled across the the threads about Gen 1 Wall Chargers not working with MCU2 cars. Has that been resolved? I also saw some folks able to charge at 40A? That would be fine for me if feasible.
 

Hayseed_MS

Member
Jan 19, 2021
444
743
Midwest
Do these wall chargers have a way of keeping track of the usage? I will be installing and my company will pay for the charging. Without adding anything else to the system, does the charger keep a tab of the kwh used?
 

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