Midea MV5-X252W/V2GN1 Service Manual page 98

4.22.4 Procedure
Compressor top temperature sensor
and/or discharge pipe temperature
sensor connections on main PCB are
Compressor top temperature sensor
and/or discharge pipe temperature
sensor have short circuited or failed
Poor heat insulation of compressor top
temperature sensor resulting in
temperature reading lower than actual
Excess refrigerant
Discharge pressure is too high
Replace outdoor main PCB
Notes:
1. Compressor top temperature sensor and discharge pipe temperature sensor connections are ports CN10 and CN11 on the main PCB (labeled 1 and 2,
respectively, in Figure 5-2.1 in Part 5, 2.2 "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 Part 2, 1 "Layout of Functional Components" and to Table 5-5.2 in Part 5, 5.1 "Temperature Sensor
Resistance Characteristics".
3. To check for excess refrigerant:

Re-start the outdoor units. If an R1 or R2 error is displayed upon start-up, there is excess refrigerant in the system.

Excess refrigerant causes discharge temperature to be lower than normal, discharge pressure to be higher than normal and suction pressure to be
higher than normal. For normal system parameters refer to Tables 5-5.4 and 5-5.5 in Part 5, 5.2 "Normal Operating Parameters of Refrigerant
System".
4. See Part 5, 4.16 "P1 Troubleshooting".
201608
PP / F0
1
loose
No
2
No
temperature
No
3
No
No
Ensure the sensors are connected
Yes
properly
Yes
Replace the faulty sensor(s)
Ensure sufficient heat insulation for
Yes
compressor top temperature senor
Discharge part of the refrigerant. Add oil
Yes
if it leaks during discharge
Yes
Troubleshoot as for a P1 error
V5 X VRF 50/60Hz
4
97