My ESS system starts feeding the grid from the battery when I put a high load on one of the 3 phases, while the other two phases are almost not loaded. This seems to be a reoccurring problem after a few tests.
Phase compestation is set to "total of all phases". The grid setpoint is set as +10w.
When all 3 phases are sort-of equally loaded, high or low load, this does not happen.
Any ideas what is going on here?
ESS with 3x multi 3K, AC coupled with 10kw Fronius symo (on AC-in, vrm dashboard incorrect due to using external current transformers) , 8x pylontech US2000C
The multi's use 3 external current sensors which are correctly installed with the 5 meter wires.
EDIT: this seems to only happen when the total load is higher than the PV output, and when above 24A (+-5,5kW load on one phase)