Midea MV6-i400WV2GN1-E - Page 117

V6-i VRF 50/60Hz
116
Midea V6-i Series Service Manual
Insufficient refrigerant caused by
refrigerant leakage
3
Yes
Add refrigerant and inspect the system
for leaks
No
The system is blocked, caused by crushed
or bent pipe, blocked EXV or dirty filter
4
Yes
Inspect the system and fix the error. If the
filter is blocked by ice, the piping should
be cleaned
No
The indoor load is too large
5
Yes
Make sure the combination ratio is less
than 130%
No
System contains air or nitrogen
6
Yes
Flush all refrigerant then vacuum the
system and recharge refrigerant. Add oil
to the system if it leaks
No
The condenser heat exchange is poor
7
Yes
Inspect the system and fix the error
No
Replace outdoor main PCB
Notes:
1. Compressor top temperature sensor and discharge pipe temperature sensor connections are ports CN4 and CN5 on the main PCB (labeled 3 and 4,
respectively, in Figure 5-2.1 in Part 5, 2.1 “Ports”). The discharge temperature switch connection is port CN19 on the main PCB (labeled 2 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 6-3.2 in Part 6, 3.1 “Temperature Sensor Resistance Characteristics”.
3. An insufficiency of refrigerant causes compressor discharge temperature to be higher than normal, discharge and suction pressures to be lower than
normal and compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. These issues disappear once sufficient
refrigerant has been charged into the system. For normal system parameters refer to Table 6-3.4 and 6-3.5 in Part 6, 3.2 “Normal Operating Parameters of
Refrigerant System”.
4. A low pressure side blockage causes compressor discharge temperature to be higher than normal, suction pressure to be lower than normal and
compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. For normal system parameters refer to Table 6-3.4 and
6-3.5 in Part 6, 3.2 “Normal Operating Parameters of Refrigerant System”.
5. 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
and 6-3.5 in Part 6, 3.2 “Normal Operating Parameters of Refrigerant System”.
6. 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 and 6-3.5
in Part 6, 3.2 “Normal Operating Parameters of Refrigerant System”.
7. 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.