Trane TVR Pro CO Series Service Manual page 101

Procedure
ODU stop valves are closed
Outdoor heat exchanger temperature
sensor connection on main PCB is loose
Outdoor heat exchanger temperature
sensor has short-circuited or failed
The indoor load is too large
System contains air or nitrogen
The condenser heat exchange is poor
The high pressure side is blocked, caused
by crushed or bent pipe or blocked EXV
Replace outdoor main PCB
Notes:
1. Outdoor heat exchanger temperature sensor connection is port CN1 on the main PCB (labeled 11 in Figure 5-2.1 in Part 5, 2.1 "Ports").
2. Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor's resistance
characteristics table, the sensor has failed. Refer to Table 6-3.1 in Part 6, 3.1 "Temperature Sensor Resistance Characteristics"
3. An indoor load that is too large causes suction and discharge temperatures to be higher than normal. For normal system parameters refer to Table 6-3.4 in
Part 6, 3.2 "Normal Operating Parameters of Refrigerant System".
4. Air or nitrogen in the system causes discharge temperature to be higher than normal, discharge pressure to be higher than normal, compressor current to
be higher than normal, abnormal compressor noise and an unsteady pressure meter reading. For normal system parameters refer to Table 6-3.4 in Part 6,
3.2 "Normal Operating Parameters of Refrigerant System".
5. In cooling mode check outdoor heat exchangers, fans and air outlets for dirt/blockages. In heating mode check indoor heat exchangers, fans and air outlets
for dirt/blockages.
6. High pressure side blockage causes discharge temperature to be higher than normal, discharge pressure to be higher than normal and suction pressure to
be lower than normal. For normal system parameters refer to Table 6-3.4 in Part 6, 3.2 "Normal Operating Parameters of Refrigerant System".
P5
No
1
No
2
No
3
No
4
No
5
No
6
No
Yes
Open the stop valves
Yes
Ensure the sensor is connected properly
Yes
Replace the sensor
Make sure the combination ratio is less
Yes
Flush all refrigerant then vacuum the
Yes
system and recharge the refrigerant. Add
oil to the system if it leaks
Yes
Inspect the system and fix the error
Yes
Inspect the system and fix the error
100
than 130%