ESS system parralel on the electric instalation (using only ac-in) when switch off the grid the 3fase system is not feeding battery power back to the electric instalation through the ac-in.
asked
My ESS system is not using battery power when grid fails.
That is the correct operation. A system should never feed back to grid when grid fails (or it is switched off).
If you want to feed loads when grid fails then you need to connect the loads to AC-OUT.
