Carrier X-POWER Series Service Manual page 160

R410A DC Inverter Series
4.14 P5: Condenser temperature T3 protection (Display on faulty unit, all the ODU in standby)
When condenser temperature is over 65℃, the system will display P5 protection, all the ODU in standby.
When the temperature goes back to normal range, P5 disappear and normal operation resumes.
P5: Condenser temperature protection
T3 port on PCB is loose
No
T3 sensor is short circuit or disabled
No
The indoor load is too large
No
The heat exchange of condenser
is not good. It may be caused by
dirty heat changer, abnormal ODU
fan running, ODU are too near to
each other, etc.
No
The high pressure side of the system is
③
blocked for squashed pipe, blocked
valve or closed stop valve
No
System contains air or nitrogen
No
Outdoor main control board
is damaged
Note:
1. How to check whether the T3 sensor is circuit or disabled
Using a multimeter 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
2. The phenomenon of the indoor load is too large
The suction temperature and discharge temperature are both higher than normal value.
3. The phenomenon of The high pressure side of the system is blocked
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.
4. The phenomenon of the system contains air or nitrogen
The high pressure is higher than normal value, current is larger than normal value, discharge temperature is higher than
normal value, compressor makes noise, pressure meter do not display steady.
178
Yes
Fasten the T3 port
Yes
①
Replace the sensor
Yes Make sure the ratio of connectable
②
IDU is less than 130% or add ODU
Yes
Check the system and
fixed up the error
Make sure all valves are open,
Yes
check the system, and remove
the obstacle
Discharge the entire refrigerant. Then
Yes
④
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Replace the outdoor main control board
①
:
②
:
④
:
Carrier service manual
③
:
Troubleshooting