Tesla Wall Connector

[Docfxit]

I'm thinking of installing a Tesla wall connector today.
I have a sub panel I can use for the 60amp breaker.
When I install a powerwall how does it communicate to the wall connector?
For the powerwall inverter to control the wall connector will it work to be installed out of two different panels. The powerwall will be connected to my main panel.

 

[h2ofun]

Not aware my wall connectors talk to anything. Depending on if you wire after the gateway or before, will determine if you could get to an PW storage. I see now value. I just got my solar as it is being sent back to PGE.

 

[jjrandorin]

I'm thinking of installing a Tesla wall connector today.
I have a sub panel I can use for the 60amp breaker.
When I install a powerwall how does it communicate to the wall connector?
For the powerwall inverter to control the wall connector will it work to be installed out of two different panels. The powerwall will be connected to my main panel.

They dont talk in the manner that you are likely thinking. With that being said, if you want the wall connector to be able to function in a power outage, it needs to be on the backup loads side of the install, or you have to have a full whole home backup. Whether it is on the backup loads side or not depends on what the plan is for installation when you get installed, etc.

 

[Docfxit]

Does the gateway feed a subpanel?
Or does the gateway communicate to the wall connector to turn it on and off through WiFi?
On your Tesla app do you see your car in the GUI?

 

[Docfxit]

Yes, I would like the wall charger to function in a power outage. I would also like the power to charge the car coming from the solar panels. I'm currently thinking the entire house will be on the backup loads side of the install. That should include everything in my 200amp service panel. Which includes the sub panel I'd like to install the wall charger into now.

 

[aesculus]

Does the gateway feed a subpanel?

You can have as many sub panels as you need for a gateway providing they don't exceed the design capacity of the gateway and powerwalls. My GW feeds 6 sub panels for example.

Or does the gateway communicate to the wall connector to turn it on and off through WiFi?

The GW has NO knowledge of a wall connector. At best Tesla can put monitors (CTs) on circuits that cannot be controlled by the GW but will display total loads including the WC on the Tesla app. If it is on the backup side of the GW then it will show up as a subset of the house load there. There is only ONE value for all loads (home) no matter what side of the GW the sub panel is on.

On your Tesla app do you see your car in the GUI?

If you have a Tesla car your app should show it. You swipe between your cars, powerwall and Tesla solar systems.

The car itself can be told to manage it's draw from your PWs (time and amount). The GW has nothing to do with this. This is just between your car and the WC and it goes through Tesla's system to coordinate it.

Note: You can easily over commit a PW with improper WC installation and/or use if on the backed up side. Putting your WC on a backup circuit controlled by a PW needs a lot of consideration and coordination by YOU, not the PW. For this reason I have my WC on the utility (non backed up side) of my system. It does mean that I cannot charge from the WC when the power is out, but I can run a smaller power circuit (plug) to a mobile connector if I absolutely needed to charge the car.

 

[Docfxit]

Aesculus: That's great. Thank you for explaining that to me. I read someplace that you can select in the app to only charge the car from solar or from the Powerwall and not from the grid.

 

[E90alex]

The wall connector is actually pretty “dumb” despite being wifi connected. The wifi only serves as the way to access the webpage-based setup/commissioning settings via IP address and for power sharing communication between multiple WC.

Cannot access or control the WC remotely or from the Tesla app, no advanced usage reports/statistics, no advanced scheduling system, no other feature you would expect from a “smart” wifi connected EVSE.

You can’t even access the settings through your home network. You have to be connected to the WC’s own ad-hoc wifi to change settings.

 

[aesculus]

Aesculus: That's great. Thank you for explaining that to me. I read someplace that you can select in the app to only charge the car from solar or from the Powerwall and not from the grid.

Yes. This is true to a point. I must confess I don't know exactly what is going on under the covers but there is nothing I am aware of in the GW itself that you set to let it know what circuit for example the WC is on. It's really about telling the car what to do. It works with any circuit actually.

Here is the details from Tesla

Vehicle Charging During Power Outage | Tesla Support

Powerwall now coordinates with Tesla vehicles during a power outage to charge your car without exceeding the energy and power capabilities of your Powerwall.

www.tesla.com

 

[jjrandorin]

Aesculus: That's great. Thank you for explaining that to me. I read someplace that you can select in the app to only charge the car from solar or from the Powerwall and not from the grid.

That isnt a feature provided by tesla as of yet. People saw that feature in some code but i am the type of person who tends to go by whats available, not what "should be coming" so, right now, there is no way to charge a tesla or any other EV, using only excess solar, with using only the tesla app.

 

[woof]

Pretty sure when the Gateway detects a grid outage, it tells the Tesla mother ship (which is how your phone gets the alert via the Tesla App that power is out). The mother ship also knows that your car is charging at home (via WiFi and/or internal cell connection+ GPS). So most likely they send a command directly to the car to stop/throttle charging when a power outage is detected

 

[aesculus]

Pretty sure when the Gateway detects a grid outage, it tells the Tesla mother ship (which is how your phone gets the alert via the Tesla App that power is out). The mother ship also knows that your car is charging at home (via WiFi and/or internal cell connection+ GPS). So most likely they send a command directly to the car to stop/throttle charging when a power outage is detected

I thought the same but then this is mentioned in the Tesla doc I referenced above?????

Tesla vehicles charging from your Powerwall during a power outage do not need to be connected to your Tesla Account, and no internet connection is necessary to support this charging feature.

 

[jjrandorin]

There are two different things being discussed here...

1. Charging from excess solar when OFF GRID.
2. Charging from excess solar under normal operation.

When the OP stated:

Aesculus: That's great. Thank you for explaining that to me. I read someplace that you can select in the app to only charge the car from solar or from the Powerwall and not from the grid.

I made the assumption (which I know, assume and all that) that point 2 is what was being discussed. Point 2 (charging from excess solar under normal operation) is not available yet.

Point 1, charging from excess solar when off grid, is an available selection in the tesla app, if the wall charger is backed up. Exactly how they accomplish it, I am not sure, but it is a setting that can be made. This is really only so that you can keep your solar producing and not drain your powerwalls when off grid.

Many of us are excited to see when tesla finally makes "point 2" available, because off grid operation is not the majority of the operation of our systems, for most of us. Its not available yet though.

 

[woof]

I thought the same but then this is mentioned in the Tesla doc I referenced above?????

Yeah, I really doubt that. The Gateway knows the state of PowerWalls and Solar Inverters (via CANbus) and various Current Sensors (via local IP connections), but I don't see how it would know about Wall Connectors, nor charging cars.

I've not seen those items in a Gateway configuration dump, nor in the Gateway API. Doesn't mean they aren't there...but they're pretty well hidden if so!

 

[aesculus]

The weird thing with this car charging control stuff is that we know if the power quality (ie how much power) drops on a wall or mobile connector, the car will in turn back off on it's demand. But if this was how they were controlling it, then there would have to be something in the GW that you set onto the circuit for the charger and we know that does not happen.

So then I started thinking perhaps there was some form of messaging like frequency shifting but that is used for controlling inverters so that's not it. And I seriously doubt any form of PLC communications either.

I am missing something obvious here, but I just don't know what it is. Its a mystery.

 

[Docfxit]

Thank you all for the discussion. I'm just trying to learn what I can. I'm at the very beginning of trying to figure out this solar/powerwall stuff. It sounds like it takes quite a few months to get it put in place even though it only takes one day to install it. I will connect my wall connector to my sub panel for now.

I'm guessing they really could control it pretty easily if they wanted to. I have a Sense that knows when certain lights in my house turn on, when the vacuum turns on, when the refrigerator turns on and a bunch of others. It tells me how many watts each device is using. And all that without communications like CANbus. So I'm sure they could do it.

 

[yblaser]

Yeah, I really doubt that. The Gateway knows the state of PowerWalls and Solar Inverters (via CANbus) and various Current Sensors (via local IP connections), but I don't see how it would know about Wall Connectors, nor charging cars.

I've not seen those items in a Gateway configuration dump, nor in the Gateway API. Doesn't mean they aren't there...but they're pretty well hidden if so!

Other people have posted but I haven't confirmed that the gateway will down shift the frequency when off grid to curtail charging if below the setting in the app for EV charging.

 

[h2ofun]

You can have as many sub panels as you need for a gateway providing they don't exceed the design capacity of the gateway and powerwalls. My GW feeds 6 sub panels for example.

The GW has NO knowledge of a wall connector. At best Tesla can put monitors (CTs) on circuits that cannot be controlled by the GW but will display total loads including the WC on the Tesla app. If it is on the backup side of the GW then it will show up as a subset of the house load there. There is only ONE value for all loads (home) no matter what side of the GW the sub panel is on.

If you have a Tesla car your app should show it. You swipe between your cars, powerwall and Tesla solar systems.

The car itself can be told to manage it's draw from your PWs (time and amount). The GW has nothing to do with this. This is just between your car and the WC and it goes through Tesla's system to coordinate it.

Note: You can easily over commit a PW with improper WC installation and/or use if on the backed up side. Putting your WC on a backup circuit controlled by a PW needs a lot of consideration and coordination by YOU, not the PW. For this reason I have my WC on the utility (non backed up side) of my system. It does mean that I cannot charge from the WC when the power is out, but I can run a smaller power circuit (plug) to a mobile connector if I absolutely needed to charge the car.

Great point, my garage 115 outlets are on the backup side. So yep, with my power from grid, and could still get to my PW's since I have the adapter to make my mobile connector 115.

 

[SageBrush]

For a variety of reasons, I like to match my EV charging load to my PV generation. I can get fancy and monitor PV generation with a CT, and then I can control my EVSE (a Grizzl-E with OCCP) programmatically to turn off charging below a specified PV generation threshold.

I still might just for the fun of it, but since my wife is willing to participate in the solution and the car spends most hours at home during the day, I found it simpler to simply set a charging window of 9am - 3pm in the car settings. We routinely plug-in when at home, and if we have a cloudy day we don't plug-in that day.

Works fine for sunny New Mexico

My point to OP is to add a pinch of social engineering to the solution.

 

[cwied]

Other people have posted but I haven't confirmed that the gateway will down shift the frequency when off grid to curtail charging if below the setting in the app for EV charging.

To add evidence to this, when you query the API, the following values are visible for the operation mode:

{
"real_mode": "autonomous",
"backup_reserve_percent": 33.5,
"freq_shift_load_shed_soe": 90,
"freq_shift_load_shed_delta_f": -0.32
}

The "freq_shift_load_shed_soe" changes when you change the off-grid EV charging reserve. This is how the gateway can "communicate" with the EV when off-grid.