Symptoms:
The Inverter is not pushing power on one phase.
The ground reference signal is erratic.
There is a
LOW_VOLTAGE_OVERLOAD_A/Bfault on the IPC.
Troubleshooting Steps:
Use Gridshare or remoteCAN to:
Confirm the system is On Grid.
Command InverterAC to Push/Pull 2kW. Check that both phases generate current. The threshold must be 2kW or more to prevent the Inverter from entering Phase Pause (an intentional FW function that turns off one phase to lower losses).
If the test is successful, the issue is unlikely to be AC relay failure. Continue TS with T3.
If the test fails, you likely have an INV with an AC relay failure.