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

Gen 3 wall connector power sharing

a1machinista1

MY5 5/24 wh/blk 19" tow-- MSLR 6/1 MSM/blk 19"
Apr 12, 2019
869
676
oregon
Right, per page 24 of the installation manual, a subpanel is not required. OTOH, even without a subpanel you are expected to have individual branch circuits to EACH wall connector, also per page 24. That's just how it is, I'm not saying I agree it should be required.

It sure looks that way. I'm confident the electricians will get it resolved. It would help if the manual didn't contradict itself.
 

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,534
1,614
Massachusetts
It would help if the manual didn't contradict itself.
There's not really any contradiction in the manual. If you put a subpanel in, you STILL need individual branch circuits off the subpanel. If you don't need a subpanel, for instance if your panel has lots of open breaker spaces and is located close to where the HPWCs will be installed, you need branch circuits for each HPWC.
 
  • Informative
Reactions: Rocky_H

a1machinista1

MY5 5/24 wh/blk 19" tow-- MSLR 6/1 MSM/blk 19"
Apr 12, 2019
869
676
oregon
There's not really any contradiction in the manual. If you put a subpanel in, you STILL need individual branch circuits off the subpanel. If you don't need a subpanel, for instance if your panel has lots of open breaker spaces and is located close to where the HPWCs will be installed, you need branch circuits for each HPWC.

I was originally looking the the "without a sub panel" schematic and I was "assuming" that the connectors were daisy chained off the main feed. But looking at it again I can see that it may mean individual 60a breakers circuits?

To me the concept of "tying" the two connectors together on the same circuit seems reasonable so to the fact that "if the software works as designed" that the two will never pull more than 48a (60a) together. And each connector has access to 48a (60a) individually. I'm not by any means an electrician and just glad our electrician is accepting of me questioning the install. Hopefully after we talk tomorrow I will have additional information that I can share here to help others through this process. I will also mention to him that he should be able to access file available to licensed electricians from Tesla.
 

Attachments

  • 5547F0FC-5E66-41DE-993F-53E22EFFF42E.png
    5547F0FC-5E66-41DE-993F-53E22EFFF42E.png
    395.2 KB · Views: 18

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,534
1,614
Massachusetts
it may mean individual 60a breakers circuits?
It >does< mean individual 60a circuits. Those upside down U's are circuit breakers.

In theory there's really no danger in having multiple HPWCs hanging off one breaker. I don't have a clue why they say to do it that way. Even if the HPWC's lose their minds and ask for more than 60 amps combined, the breaker will trip and your house won't burn down.

I also think the repeated use of 60A on page 24 is misleading. I don't think there's any requirement that the shared power supply and wiring all be rated to 60 amps. I imagine it would be just fine sharing a 30 amp circuit too(with 30 amp breakers and wiring all around). Maybe Tesla is worried some numbnuts will put two thirty amp circuits hanging of a single 60 amp breaker and burn someone's house down by telling the HPWC master that its got 60 amps to play with.
 
Without power sharing, you can only set each HPWC as if it has a 30 amp breaker, or opt to only use one connector at a time.

The good news is that power sharing is now supported on Gen3 HPWC's.

The cars won't self regulate at all. They only know what the HPWC tells them they can have, current wise.
Unfortunately, after my installation of two of these BEFORE power sharing was available, I did a software update and apparently ended up with firmware that couldn’t/wouldn’t download new firmware and always reported they were up to date.

I just successfully updated using the manual/offline update procedure outlined on various Tesla support pages and now have power sharing enabled.

Happy to have half-speed charging behind us! 😀👍🏻
 
  • Like
Reactions: EchoDelta

EchoDelta

Supporting Member
Supporting Member
Mar 5, 2012
1,269
686
RootedNW.org, Seattle, Planet Earth
Unfortunately, after my installation of two of these BEFORE power sharing was available, I did a software update and apparently ended up with firmware that couldn’t/wouldn’t download new firmware and always reported they were up to date.

I just successfully updated using the manual/offline update procedure outlined on various Tesla support pages and now have power sharing enabled.

Happy to have half-speed charging behind us! 😀👍🏻
Mind sharing which version # you were "stuck" on?
 

moonshine83

Member
Jul 9, 2021
9
0
USA
Right, per page 24 of the installation manual, a subpanel is not required. OTOH, even without a subpanel you are expected to have individual branch circuits to EACH wall connector, also per page 24. That's just how it is, I'm not saying I agree it should be required.
good 2 know. ty
 

Chemios

Member
Jul 1, 2021
123
180
South Jersey
I just successfully updated using the manual/offline update procedure outlined on various Tesla support pages and now have power sharing enabled.
if you only have one car plugged in, will ituse the full allowed amperage to charge that single car at max speed?

Also, if you have 2 cars plugged in, does it have any intelligence to determine what car is done charging? Or does it work in half capacity if 2 cars are plugged in regardless of SoC?
We just ordered our second Tesla, so trying to figure this all out.
 

captjoemcd

Member
Nov 29, 2019
258
293
California
if you only have one car plugged in, will ituse the full allowed amperage to charge that single car at max speed?

Also, if you have 2 cars plugged in, does it have any intelligence to determine what car is done charging? Or does it work in half capacity if 2 cars are plugged in regardless of SoC?
We just ordered our second Tesla, so trying to figure this all out.
The WCs communicate with each other based on actual current draw. If two cars are plugged in and one is not charging the other will get the max available. So 2 WCs with 60A breakers (48A max continuous) on a 100A subpanel (80A total max continuous), one car plugged or 2 plugged with one charging will get 48A. 2 cars plugged and charging will split the 80A (from what I’ve seen it isn’t perfectly 50/50 but close, regardless of relative SoCs)
 
  • Like
Reactions: Chemios

Chemios

Member
Jul 1, 2021
123
180
South Jersey
The WCs communicate with each other based on actual current draw. If two cars are plugged in and one is not charging the other will get the max available. So 2 WCs with 60A breakers (48A max continuous) on a 100A subpanel (80A total max continuous), one car plugged or 2 plugged with one charging will get 48A. 2 cars plugged and charging will split the 80A (from what I’ve seen it isn’t perfectly 50/50 but close, regardless of relative SoCs)
Thanks for the detailed response, much appreciated.
 

Sophias_dad

Supporting Member
Supporting Member
Jul 29, 2018
1,534
1,614
Massachusetts
I gotta say I was 'shocked' to see that power sharing can even be configured on differently wired/breakered HPWCs, so you could have one wired for 48 amps while another is wired for 12, and they won't ever try overdrive the 12 amp circuit. I know the software to do that is trivial, but it seems like a very uncommon use case.

 

a1machinista1

MY5 5/24 wh/blk 19" tow-- MSLR 6/1 MSM/blk 19"
Apr 12, 2019
869
676
oregon
Update: The Head Electrician came over about 10 days ago and we had a 30 min discussion about the install. He took some notes and I sent him another link to the Tesla install guide. He was scheduled for vacation last week and said he would contact me Tomorrow when he returns to work. In the meantime we picked up our MY so I reduced both HPWCs to 30a and am currently charging our MY on the "Follower" HPWC. We won't get our MS until ? ( Current EDD 10/12-11/1) so we have time to spare. Will update as the situation progresses.
 

a1machinista1

MY5 5/24 wh/blk 19" tow-- MSLR 6/1 MSM/blk 19"
Apr 12, 2019
869
676
oregon
Update: The owner sent me an email stating that they think the best way to move forward is to install a sub panel and wire each HPWC to its own breaker. Although they believe the current wiring is acceptable and I agree to a certain point. They will be coming over this week to revamp the wiring. I have agreed to pay for the materials (sub panel and breakers) and half of the additional labor. The owner made it clear to me that I could name my terms on this, but I consider the parts and half labor to be fair. As a whole I am happy with what the end result will be. I could have made a stink and possibly had no additional costs but all said and done we will have paid $1100 for two HPWC installed.
 
if you only have one car plugged in, will ituse the full allowed amperage to charge that single car at max speed?

Also, if you have 2 cars plugged in, does it have any intelligence to determine what car is done charging? Or does it work in half capacity if 2 cars are plugged in regardless of SoC?
We just ordered our second Tesla, so trying to figure this all out.
Yes to both questions.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top