IF THE AC INPUT VOLTAGE EFFECTIVE VALVE TESTS LESS THAN 50V FOR +3 SECONDS WHEN THE RELAY OF THE OUTDOOR UNIT PCB POWER SUPPLY WORKS, THE AC UNIT WILL STOP WORKING IMMEDIATELY FOR PROTECTION.
REPAIR:
1) IT IS A NORMAL PROTECTION IF THE POWER SUPPLY HAS LARGE FLUCTUATIONS
2) WHEN EU ERROR CODE APPEARS, TEST THE VOLTAGE BETWEEN N AND L WITH A DIGITAL MULTIMETER. IF THE VOLTAGE IS LESS THAN 50V, IT IS A NORMAL PROTECTION. IF THE VOLTAGE IS HIGHER THAN 50V, THE PROBLEM MAY BE FROM THE VOLTAGE SAMPLING CIRCUIT. PLEASE REPLACE THE OUTDOOR UNIT PCB OR INSPECT THE SAMPLING CIRCUIT