Wall Connector Usage Reporting Messed Up?

[delightfulnest]

I currently have a 4.8kW system with Powerwall+. The Powerwall+ is backing up 100A load center that is in turn connected to my 200A main panel via a 100A breaker. The 200A panel upgrade was done by Tesla at the same solar installation project. My house is small, so the 200A main panel only included the 100A Powerwall breaker, and nothing else.

Because the 100A load center is already filled, I installed my Gen3 Tesla Wall Connector into my main panel. The installation and setup all went smoothly; the charger is working as intended.

However, the Tesla app usage reporting across my house is now all messed up. Typically, the idle load on my house is ~0.3-0.4kW. When the car (a Tesla) is charging at 32A (drawing 7kW), the Tesla app would show home usage at 0kW, and the car usage as 0.3kW. I believe I should be seeing 7kW for the car, and 0.3kW for the house in the Tesla app.

I suspect that my Tesla app is not monitoring any usage outside of the 100A load center. Has anyone encountered similar issue? Has anyone been able to get Tesla to monitor the whole house (i.e. include circuits in the 200A main panel)?

 

[offandonagain]

Yes this is a known issue. Tesla will subtract the car charging power (which it gets from the car) from the home usage (which is gets from the solar CT+grid CT in the gateway). If the car charger is not monitored--which is the case for loads that are not backed up unless a separate CT is installed--the math doesn't work out and the app doesn't handle that correctly.

I believe Tesla can install an extra CT to monitor loads that are not backed up. In my case, I just disabled Charge on Solar which is also broken because of this. I'm not sure if just adding a Wall Connector to the app also causes this issue.

 

[miimura]

This is very common. Based on your description, I would expect the Grid flow to be measured by the CTs built into the Gateway 2. This is the proper configuration as the system was installed. You installed something after the fact that requires a configuration change to the Grid flow measurement. This can be done by either connecting a new CT placed in the main panel and wiring it back to the Gateway or by using a Remote Neurio in the main panel and configuring the Gateway to treat it as the Grid flow instead of the built-in CT. If Tesla installed your system, you will have to have them come back out to change the CT configuration. If you used an independent installer, they should do it. Since the Wall Connector was not part of the original installation, I would expect to pay extra for this change.

 

[delightfulnest]

Thank you all for your responses. I ended up stumbling upon the Gateway 2 installation quick guide:

https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall_2_Gateway_2_Installation_Quick_Guide_NA_EN.pdf

Page 15 clearly stated that my current setup (i.e. lack of CT meters at the main panel) is incorrect. I will see if Tesla can rectify the situation by adding the correct CT meter at the main panel (i.e. non-backup site loads).

 

[CrazyRabbit]

Did your installation not have any circuits in the non backed up panel after Tesla’s installation? If so you might have to pay tesla to install CT’s. But if you had loads left in non backed up loads center the CT’s should have had CT’s. Some panels don’t have space to install CT’s and the you need to monitor the circuits individually.

 

[CrazyRabbit]

I don’t trust the calibration of tesla external CT. The calibration of the external CT for solar that came with my panel was 20% high. I wonder if tesla is doing this on purpose so people aren’t complaining about their solar production. To fix tesla installed a neurio for solar monitoring..

 

[delightfulnest]

Did your installation not have any circuits in the non backed up panel after Tesla’s installation? If so you might have to pay tesla to install CT’s. But if you had loads left in non backed up loads center the CT’s should have had CT’s. Some panels don’t have space to install CT’s and the you need to monitor the circuits individually.

There were only 5 circuits in the 200A main service panel that has 48 slots. Tesla moved all of the circuits from the service panel into the backup load center, and no circuits were left in the main panel except for the breaker going to the Gateway. However, the backup load is only 100A, and the 5 circuits have maxed out the 100A load center. That's why I cannot install a 60A breaker for the Wall Connector in the load center.

I am just confused as to why Tesla didn't install the CT meters at the main panel per the quick start guide I linked above, which would have accommodated any future non-backup loads. The way they did it pretty much pigeonholed me into a 100A setup.

 

[jjrandorin]

I am just confused as to why Tesla didn't install the CT meters at the main panel per the quick start guide I linked above, which would have accommodated any future non-backup loads. The way they did it pretty much pigeonholed me into a 100A setup.

I believe you answered the question already, when you said:

Tesla moved all of the circuits from the service panel into the backup load center, and no circuits were left in the main panel except for the breaker going to the Gateway.

There were no circuits left there, so it wasnt on the plans to monitor it.

Hopefully you should be able to pay them to come back out and do it, if its possible, but if you are going to them saying "you did it wrong, you need to XXXX and it should be free", you may have a lot more trouble getting anywhere.