WHEN THE DISCHARGE TEMPERATURE IS MORE THAN T DEGREES CELCIUS (110 DEGREES CELCIUS FOR EXAMPLE), THE OUTDOOR PCB WILL SWITCH OFF THE AC UNIT AND DISPLAYS THE P4 ERROR CODE.
REPAIR:
1) IT IS A NORMAL PROTECTION IF THE DISCHARGE TEMPERATURE IS MORE THAN T DEGREES CELCIUS
2) CHECK IF THE SENSOR IS ELL CONNECTED TO THE PCB
3) CHECK IF THE DISCHARGE TEMPERATURE SENSOR IS BROKEN. IS THERE AN OPEN CIRCUIT? IS THERE ANY RESISTANCE DRIFT?
4) CHECK IF THE OUTDOOR UNIT FAN MOTOR STOPPED ITS OPERATION
5) IF THE INSPECTIONS/REPAIRS DESCRIBED ABOVE ARE ALL OK, PLEASE REPLACE THE OUTDOOR UNIT PCB