Midea VRF Series User Manual

V6R VRF 50/60Hz
129
Part
6
-
Diagnosis and Troubleshooting
… flowchart continued from previous page
Excess refrigerant
2
Yes
Discharge part of the refrigerant. Add oil
if it leaks during discharge
No
System contains air or nitrogen
3
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
4
Yes
Inspect the system and fix the error
No
The high pressure side is blocked, caused
by crushed or bent pipe or blocked EEV
5
Yes
Inspect the system and fix the error
No
Inverter module has short-circuited
6
Yes
Replace the inverter module
No
Compressor has malfunction
7
Yes
Replace the compressor
No
DC fan inverter board has short-circuited
8
No
Replace the outdoor main PCB
Notes:
1. An indoor load that is too large causes suction and discharge temperatures to be higher than normal.
2. 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 excess refrigerant system parameters refer to Table 6-4.4 in Part 6, 4.3 “Parameters of Excess and Insufficient Refrigerant System”.
3. 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 insufficient refrigerant system parameters refer to Table 6-
4.5 in Part 6, 4.3 “Parameters of Excess and Insufficient Refrigerant System”.
4. 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.
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 insufficient refrigerant system parameters refer to Table 6-4.5 in Part 6, 4.3 “Parameters of Excess and Insufficient Refrigerant
System”.
6. Set a multi-meter to buzzer mode and test any two terminals of P N U V W of the inverter module. If the buzzer sounds, the inverter module has short-
circuited.
7. The normal resistances of the inverter compressor are 0.05-0.15Ω among U V W and infinite between each of U V W and ground. If any of the resistances
differ from these specifications, the compressor has malfunction.
8. Set a multi-meter to buzzer mode and test any two terminals of P N U V W of the DC fan drive board. If the buzzer sounds, the DC fan drive board has short-
circuited.
Replace the DC fan inverter board
Yes

Midea VRF Series Specifications

General

Compressor Type	Inverter Scroll Compressor
Type	Variable Refrigerant Flow (VRF)
Refrigerant	R410A
Control	Centralized control, individual control
Indoor Unit Types	Wall mounted, cassette, ducted, floor standing
Energy Efficiency	High energy efficiency with DC inverter technology
Indoor Unit Noise Level	19 dB(A) to 45 dB(A)