1) THERE IS A VOLTAGE TEST CIRCUIT ON THE OUTDOOR UNIT PCB. WHEN THE AC VOLTAGE TESTS Vó145V, THE MCU WILL PREVENT THE UNIT TO START UP. IF THE UNIT ALREADY STARTED TO OPERATE, IT WILL STOP WORKING AND THE P1 ERROR CODE WILL BE DISPLAYED. WHEN THE INPUT VOLTAGE COMES BACK AS Vò155V, THE UNIT WILL RECOVER TO ITS PREVIOUS OPERATING CONDITION.
2) THERE IS A DC BUS VOLTAGE TEST CIRCUIT ON THE PCB. WHENEVER THE TEST VOLTAGE BETWEEN DC+ AND GROUND IS MORE THAN DC 420V OR LESS THAN DC 150VM THE MCU WILL PREVENT THE UNIT TO START UP. IF THE UNIT ALREADY STARTED TO OPERATE, IT WILL STOP WORKING AND THE P1 ERROR CODE WILL BE DISPLAYED. WHEN THE VOLTAGE COMES BACK AS 190VóVó410V, THE UNIT WILL RECOVER TO ITS PREVIOUS OPERATING CONDITION.
REPAIR:
1) IT IS A NORMAL PROTECTION IF THE VOLTAGE FLUCTUATES TOO MUCH
2) CHECK WHETHER THE VOLTAGE IS 145VóVó260V. IF V<145V OR V>260V, ERROR CODE P1 IS A NORMAL PROTECTION
3) TEST THE OUTDOOR UNIT PCB DC BUS VOLTAGE, NORMALLY IT SHOULD BE 150VóVó420V. IF NOT, THE UNIT WILL BE PROTECTED AND THE P1 ERROR CODE WILL BE DISPLAYED (THE PCB DC BUS VOLTAGE CAN BE TESTED BETWEEN THE LARGE ELECTROLYTIC CAPACITOR)
4) IF BOTH THE POWER SUPPLY AND THE DC BUS VOLTAGE ARE NORMAL, PLEASE CHECK THE VOLTAGE SAMPLING CIRCUIT. IF NECESSARY, PLEASE REPLACE THE OUTDOOR UNIT PCB