Midea MV5-X252W/V2GN1 Service Manual page 86

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System contains air or nitrogen
The high pressure side is blocked, caused
by crushed or bent pipe or blocked EXV
The condenser heat exchange is poor
Replace outdoor main PCB
Notes:
1. The high pressure sensor connection is port CN17 on the main PCB (labeled 30 in Figure 5-2.1 in Part 5, 2.2 "Ports").
2. Measure the resistance among the three terminals of the pressure sensor. If the resistance is of the order of mega Ohms or infinite, the pressure sensor
has failed. Refer to Part 2, 1 "Layout of Functional Components".
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. 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 Tables 5-5.4 and 5-5.5
in Part 5, 5.2 "Normal Operating Parameters of Refrigerant System".
5. 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 Tables 5-5.4 and 5-5.5 in Part 5, 5.2 "Normal Operating Parameters of Refrigerant System".
6. 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.
201608
4
No
5
No
6
No
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
V5 X VRF 50/60Hz
85