R410A All DC Inverter V4+S Series 60Hz    MCAC-VTSM-2015-09 
158 Troubleshooting 
4.25   PL: Temperature protection of main inverter module 
4.26   C7: PL protection appears three times in 100 minutes 
When the temperature of inverter module is over 80
o
C, it will display PL protection. 
If the system displays PL protection three times in 100 minutes, the system will stop and display C7 error code. 
When the system displays C7 error code, the system can resume only by restarting the machine. 
 
* How to check for the temperature sensor 
Using a multi-meter to measure resistance, if the resistance is too low, the sensor is short circuit, if the resistance at certain 
temperature is not consistent with attached table 2, the sensor is disabled 
   
The screw between inverter 
module and radiating fin is 
Outdoor main PCB is damaged 
Replace the outdoor main PCB 
Temperature sensor of main 
inverter module has short 
circuited or is disabled*. 
Tighten the screw; make sure 
the inverter module is closed to 
the radiating fin