MCAC-VTSM-2015-10      R410A All DC Inverter V5 X Series 50Hz 
Troubleshooting 151 
4.23   P5: Condenser temperature protection 
When condenser temperature is over 65
o
C (149
o
F), the system will display P5 protection, the ODUs will go on 
standby.  When  the  temperature  goes  back  to  normal  range,  P5  protection  finishes  and  normal  operation 
resumes. 
 
 
 
Note:   
T3/T5: Sensor for condenser pipe; 
* How to check for T3/T5 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 1, the sensor is disabled 
* The phenomenon of large indoor load 
The suction temperature and discharge temperature are both higher than normal value. 
* The phenomenon of high pressure side blockage 
The high pressure is higher than normal value, the low pressure is lower than normal value, and the discharge temperature is 
higher than normal value. 
* The phenomenon air or nitrogen in the system 
The high pressure is higher than normal value, current is larger than normal value, discharge temperature is higher than normal 
value, abnormal compressor noise, pressure meter is not steady.   
Outdoor main PCB is damaged 
Replace the outdoor main PCB 
P5: Condenser temperature protection 
T3/T5 port on main control board is loose 
T3/T5 sensor has short circuited or is disabled* 
The indoor load is too large* 
Make sure the ratio of connectable IDU is 
less than 130% or add ODU 
Low condenser heat exchange, causes 
may include dirty heat exchanger, 
abnormal ODU fan operation, too closed 
outdoors installation, etc. 
Inspect the system and fix the error 
The high pressure side of the system is 
blocked, caused by crushed or bent pipe, 
blocked valve or closed stop valve* 
Make sure all valves are open, ensure free 
refrigerant flow 
System contains air or nitrogen* 
Flush all refrigerant. Then vacuum the 
system and recharge the refrigerant. Add 
oil to the system if it leaks