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Wall connector questions

asolof

Member
Sep 26, 2020
38
6
New Jersey
I am unclear about some points:

1. Is the commissioning just to
a. Set the breaker amps and max charge rate for the circuit
b. and Connect to your WiFi ?
c. Anything else?
2. Is the Wall Connector's connection to your WiFi network only so that when you push the button on the charge port the car's charge port opens? Is it used for anything else?

3. All charge programming is done via the car's computer, not the wall connector?

 

LNL_HUTZ

Member
Aug 3, 2020
300
237
San Francisco
I assume you're asking about a Gen 3 wall connector. You don't need WiFi to open the port with the connector plug (my Gen 2 does it). I think the WiFi is more for future applications or to allow the HPWC to communicate with a Powerwall. I guess Tesla can probably also push firmware updates to it if need be.
 

asolof

Member
Sep 26, 2020
38
6
New Jersey
I assume you're asking about a Gen 3 wall connector. You don't need WiFi to open the port with the connector plug (my Gen 2 does it). I think the WiFi is more for future applications or to allow the HPWC to communicate with a Powerwall. I guess Tesla can probably also push firmware updates to it if need be.
ok, Thanks!
 

drotto25

Member
Sep 22, 2020
63
23
NJ
Wifi also allows multiple Powerwalls to communicate, if they are sharing a circuit, so they can optimize charging of multiple vehicles.
 

asolof

Member
Sep 26, 2020
38
6
New Jersey
Wifi also allows multiple Powerwalls to communicate, if they are sharing a circuit, so they can optimize charging of multiple vehicles.

I was just reading about that feature. Unfortunately, you still need to run a separate circuit line (electrical cable) from the electrical panel to each charger. Wouldn't it have been nice if they had implemented it in such a way the one cable could feed into one panel into the garage and that one cable could be shared with several wall connectors instead of having to install separate cable runs or a remote electrical panel in the garage?
 

drotto25

Member
Sep 22, 2020
63
23
NJ
I was just reading about that feature. Unfortunately, you still need to run a separate circuit line (electrical cable) from the electrical panel to each charger. Wouldn't it have been nice if they had implemented it in such a way the one cable could feed into one panel into the garage and that one cable could be shared with several wall connectors instead of having to install separate cable runs or a remote electrical panel in the garage?
I think they can share a 100 amp circuit, and the Wifi allows them to distribute the amps to optimally charge both cars.
 

asolof

Member
Sep 26, 2020
38
6
New Jersey
I think they can share a 100 amp circuit, and the Wifi allows them to distribute the amps to optimally charge both cars.

Yes. Multiple cars. But each wall charger needs its own cable back to the electric supply panel. It would be nice if they could share the cable as well as the power.
 

jstjohnz

Member
Sep 7, 2020
103
64
Indianapolis
Yes. Multiple cars. But each wall charger needs its own cable back to the electric supply panel. It would be nice if they could share the cable as well as the power.

If you have a total of 60 amps to share between 2 wall connectors, I don't know why they couldn't be on the same breaker. I mean the box has no way of knowing! I think this would be a very common scenario for residential.

If you're sharing more than 60 total amps then it makes more sense, but even then you could run one circuit from the main panel and have a subpanel near the wall connectors to give each one it's own breaker.
 

asolof

Member
Sep 26, 2020
38
6
New Jersey
If you have a total of 60 amps to share between 2 wall connectors, I don't know why they couldn't be on the same breaker. I mean the box has no way of knowing! I think this would be a very common scenario for residential.

If you're sharing more than 60 total amps then it makes more sense, but even then you could run one circuit from the main panel and have a subpanel near the wall connectors to give each one it's own breaker.

I'm not an electrician, but I believe a subpanel near the connectors would work fine. Given the cost of having a subpanel installed, it would be nice if the wall connectors could provide that function for sharing one cable, obviating the subpanel.

Subpanel Installation Cost
The cost to install a subpanel is $400 to $1,750. This depends on the amperage and the number of circuits. Models have 4 to 20 or more circuits, and the amperage ranges from 100 to 150 amps.

100 $400 - $1,000
125 $500 - $1,250
150 $600 - $1,750
 
Last edited:

fparent

Member
Sep 4, 2018
41
20
Cleveland
I assume you're asking about a Gen 3 wall connector. You don't need WiFi to open the port with the connector plug (my Gen 2 does it). I think the WiFi is more for future applications or to allow the HPWC to communicate with a Powerwall. I guess Tesla can probably also push firmware updates to it if need be.
Shouldn't the car's own wifi be able to do this? Wifi on the wall connector seems redundant for this purpose.
 

fparent

Member
Sep 4, 2018
41
20
Cleveland
If you have a total of 60 amps to share between 2 wall connectors, I don't know why they couldn't be on the same breaker. I mean the box has no way of knowing! I think this would be a very common scenario for residential.

If you're sharing more than 60 total amps then it makes more sense, but even then you could run one circuit from the main panel and have a subpanel near the wall connectors to give each one it's own breaker.
You can't do that. A wall charger uses 40 amps so you can't have two on the same circuit.

And the idea that the chargers will use their wifi to share power is misconstrued. How would a charger know it's standalone as opposed to be sharing a circuit with another charger that happens to have its wifi offline or miss configured?

Residential electricity is all about certainty and never about assumption.

One possibility would be to have the wall charger connected to a control box, itself connected to two cars with a manual switch to select one car at a time. A "smart" version of that box could be programmed to switch cars based on some logic like preset time, duration, etc.
 
Last edited:

asolof

Member
Sep 26, 2020
38
6
New Jersey
You can't do that. A wall charger uses 40 amps so you can't gave two on the same circuit.

And the idea that the chargers will use their wifi to share power is misconstrued. How would a charger know it's standalone as opposed to be sharing a circuit with another charger that happens to have its wifi offline or miss configured?

Residential electricity is all about certainty and never about assumption.

One possibility would be to connect the chargers to a control box with a manual switch to select which charger will be delivering power.

To have that functionality I'm locating my wall charger between the 2 cars so that the 18-foot cord can reach either.
 

akenham

M3 LR AWD+ 2020
Sep 19, 2020
78
86
East Anglia, UK
Note that sharing available current between multiple wall connectors is also a feature of the gen2 wall connectors - there is additional signalling cabling between the wall chargers for this rather than wifi.

My suspicion is that the gen3 does it the same way as relying on wifi (or the cars to negotiate) would be risky - you wouldn't want both chargers trying to draw max current if they lost contact (or defaulting to slow charging) - having extra signal cabling isn't much of a pain given the high current supply cable must be run anyhow.

The sharing is a neat feature if you have multiple cars - you could imagine doing it purely via the cars choosing sensible current limits, but again this is vulnerable to the car loosing connectivity and "just charging" as instructed without a backstop of signal cabling.
 

jstjohnz

Member
Sep 7, 2020
103
64
Indianapolis
You can't do that. A wall charger uses 40 amps so you can't have two on the same circuit.

The Gen2 wall connectors can share a circuit, so what makes Gen 3 different in that respect?

I don't know why you say "the idea that the chargers will use their wifi to share power is misconstrued". How so?
This has been stated as a gen 3 feature that will be supported in a future firmware. There is no capability for hard-wired signaling between Gen 3 units so it has to be done over wifi. Each WC would have to be configured to know what other WCs it was sharing current with as well as the total number of amps available to all WCs combined. Each unit would only need to broadcast the number of amps it 'wants' periodically. At that point each WC knows the total number of requested amps, and can assign itself an appropriate amp limit.

Example:
A wants 48 amps
B wants 40 amps
C wants 32 amps

Total of 80 amps available. Total available / total requested = 80/120. Each WC is allocated 2/3 of it's requested amps:
A gets 32 amps
B gets 27 amps
C gets 21 amps

Yes you would have to allow for the situation where a WC didn't respond over wifi, perhaps by allowing non-communicating units to get 1/n of the total amps, where n is number off WCs sharing.
 

asolof

Member
Sep 26, 2020
38
6
New Jersey
Yes, they can share a circuit, but not a cable. At least that is my understanding from studying the wall connector manual. The one shared circuit is somehow connected at the electrical panel but there needs to be a separate cable from that panel run to each wall connector. If I misunderstood that, please correct me. The wall connectors talk to each other via wifi so as to divide up their collective draw to stay within the amperage limit of the one circuit.

So, that optimizes the use of limited amperage on the circuit. But still requires separate cable runs for each wall connector.

Say, for example, you have a 60 amp circuit and 2 long-range model Y's in the garage. They each would optimally draw 48 Amps if available. If during the charging, both were charging, they would temporarily divide up the 48 amps until one of them finished and the remaining wall connector would provide 48 amps again to the one remaining active charger.
 

jstjohnz

Member
Sep 7, 2020
103
64
Indianapolis
I checked the manual and it says:

"For sites with multiple Wall Connectors, each Wall Connector must have its own branch circuit with L1,L2/N, and Ground."

Note: L2/N is L2 for 240V installations and neutral for 120V installations. No neutral needed for 240V.


 

fparent

Member
Sep 4, 2018
41
20
Cleveland
I checked the manual and it says:

"For sites with multiple Wall Connectors, each Wall Connector must have its own branch circuit with L1,L2/N, and Ground."

Note: L2/N is L2 for 240V installations and neutral for 120V installations. No neutral needed for 240V.
That makes sense to me to have independent electrical circuits for safety reasons.
I don't know why you say "the idea that the chargers will use their wifi to share power is misconstrued". How so?
I stand corrected.
 

toneman82

Member
Sep 7, 2020
55
31
Phoenix
If you look in the gen 3 install manual, there is an option for each charger to have 'its own circuit' from a sub panel in the garage. We are installing a 2nd charger for a 2nd Tesla, and my electrician confirmed this is an option.

But to future proof, we are installing a dedicated line back to the panel, making space by switching some breakers to the 1/2 sized ones. Each charger will be limited to the max 40A we currently have (in sharing mode), or 20A each in non-sharing because our 200A service is full. And a 400A service upgrade is going to be big bucks. But maybe in the future we add solar and can get full power to each charger.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,785
8,393
Boise, ID
If you look in the gen 3 install manual, there is an option for each charger to have 'its own circuit' from a sub panel in the garage. We are installing a 2nd charger for a 2nd Tesla, and my electrician confirmed this is an option.
It probably, likely, should be an option sometime in the future, soon, eventually.
Tesla released the Gen3 with that function not implemented yet and has no schedule of when they will have it available.
 

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