Sunsynk Fault Codes

I believe the fault relate to a Ground Fault. I believe that the F03 code is a DC leakage current fault. Before the inverter starts to connect to the grid, the inverter will first detect the impedance of PV + to ground, and the impedance of PV – to ground. The inverter detect the DC leakage current is too high. Sometime DC-DC MOSFT damage or may DC-DC power supply have some issue.

You should probably test you PV does not have an earth fault.

Try starting the inverter by only turning on he Grid connection leaving the PV and battery isolators off and see if the inverter powers up normally.

Then press the Start Button this will start the inverter

If there is no fault, then close the battery isolator. If the battery DC is the cause of the fault then the system should fault.

If not then try closing the PV isolator. If the fault returns then you have a PV fault.

The most like issue is the PV and the fault mayonly happen under certian condition, eg. excess temperature, or moisture, or a faulty panel or connection.