I have an Easysolar 5kVA 48V unit connected to 4 x 220Ah Victron AGM batteries and 12 x 330W PV panels. The system is connected to the RED phase of a 3 phase system feeding a large house. There are no 3 phase loads connected to this supply. At random times the inverter will enter PASSTHRU mode and feed power back into the grid, even though the GRID tab in the VECONFIG file has been set so as to not allow power to be fed from the DC to the GRID. Sometimes it will happen for very short periods but i have seen it going on for up to 30 minutes.