A: The troubleshooting steps are as follows:
1.   Check the Phase Loss Percentage Setting: Inspect the phase loss percentage setting in the power settings. The factory default is typically 70%. This alarm will trigger when the phase voltage drops below this set value.
2.  Check for Grid Voltage Fluctuations: Use a multimeter to measure the voltage between the input terminals of the circuit breaker Q1 and the neutral line. Observe if the voltage ever falls below 154V. If the voltage is below 154V, this indicates a grid fluctuation issue that needs to be addressed by the customer's facility team.
3.  Inspect Wiring on the Main Control Board: Power off the unit completely. Then, check the power detection wiring at port J31 on the main control board. Disconnect the terminal and check if the wiring connections are secure. Trace the wiring to check if the connections at the circuit breaker Q3 are loose and verify that the wire sequence is correct.
4.  Replace the Control Board: If all the above steps are checked and confirmed correct, but the issue persists, it will be necessary to replace the control board.