Midea ATOM B Series Service Manual page 80

2.23 L0/L1/L2/L4/L5/L7/L8/L9: L category of inverter module protection (For all models)
2.23.1 Digital display output
L0/L1/L2/L4/L5/L7/L8/L9
2.23.2 Description
 Compressor inverter module protection.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.23.3 Trigger / recover condition
 Trigger condition: Inverter module or compressor is abnormal.
 Recover condition: Inverter module and compressor goes back to normal.
 Reset method: Manually restart.
2.23.4 Possible causes
 Power supply is abnormal.
 Refrigerant cooling module is abnormal.
 Compressor is abnormal.
 Outdoor unit main control board damaged.
2.23.5 L0/L4: Procedure
U V W wires between inverter module
and compressor is not connected
Whether refrigerant cooling pipe
assemble properly
Replace the main control board to check
whether the fault is occur again
Exclude whether system is abnormal
and compressor has any abnormal noise
Replace the compressor
L0 / L4
properly
No
Yes
Yes
No
Atom B Series VRF 50/60Hz
Yes
Ensure U V W wire is connected properly
Reinstallation to confirm refrigerant
No
cooling pipe contact with radiator tightly
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