MCAC-VTSM-2015-10      R410A All DC Inverter V5 X Series 50Hz 
Troubleshooting 163 
4.29   PP: Insufficient overheat degree protection of compressor discharge temperature 
4.30   F0: PP protection appears three times in 150 minutes 
When the discharge temperature overheat degree is≤0
o
C for 20min; or the overheat degree is≤5
o
C for 60min, 
it will display PP protection. 
If the system displays PP protection three times in 150 minutes, the system will stop and display F0 error code. 
When the system displays F0 error code, the system can resume only by restarting the machine. 
 
 
Note: 
* How to check for the temperature sensor 
Using a multi-meter to measure resistance, if the resistance is too small, the sensor is short circuit, if the resistance in certain 
temperature is not consistent with attached table 2, the sensor is disabled. 
* The phenomenon of excess refrigerant is 
The high pressure is higher than normal value, the low pressure is higher than normal value, and the discharge temperature is 
lower than normal value. 
   
Outdoor main PCB is damaged 
Replace the outdoor main PCB 
PP: Insufficient overheat degree 
protection 
Install the sensor correctly, or fasten 
the cable, or replace the sensor 
Compressor top temperature sensor is 
not installed correctly or sensor cable is 
loose or disabled* 
Poor heat insulation of compressor top 
temperature sensor resulting in test 
temp. lower than actual temp. 
Ensure sufficient heat insulation for 
compressor top senor 
Discharge part of the refrigerant. Add 
oil if it leaks during the discharge 
System discharge pressure is too high 
Refer to P1 troubleshooting