Backup Circuit Quesiton

[jeverest]

I have a 9kw solar array and a series 2 powerwall currently installed. As I understand it, the house is completely backed up via the powerwall. I have confirmed this and everything seems to work as expected.

However, there is one thing I don't understand. I have one circuit that remains outside the backed up circuit, a hot tub. Whenever the hot tub clicks on I can see a large 6kw power draw from the grid (which makes sense) and from the powerwall. It is this draw from the powerwall I don't understand. If the hot tub is not part of the backed up circuit I would have expected it to be completely powered from the grid and not consume any solar or powerwall resources. Anyone understand what is happening there?

 

[power.saver]

Yes, the CTs that measure grid flow were placed ahead of the hot tub circuit, so it is measured as load and the solar/powerwall will contribute to it. But during an outage, the hot tub will not be powered and not affect solar/powerwall.

 

[zanary]

power.saver is correct. Circuits outside of the Powerwall Load Center are NOT powered during a grid outage, but will be powered by the Powerwall and grid in other circumstances.

 

[jeverest]

That solves that mystery. Thanks power.saver and zanary!