Midea ATOM B Series Service Manual page 59

Atom B Series VRF 50/60Hz
2.10 EF: PFC fault (For all models)
2.10.1 Digital display output
EF
2.10.2 Description
 PFC fault protection.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.10.3 Trigger / recover condition
 Trigger condition:
DC bus
 Recover condition:
DC bus
 Reset method: Manually restart.
2.10.4 Possible causes
 DC fan motor damaged.
 Main PCB damaged.
2.10.5 Procedure
Detect the 220V power supply input port to
see whether the voltage is stable
Power off for 3 minutes and then repower on
Check whether fault is cleared
Outdoor unit main control board damaged
58
voltage is over 450V for continue 3 S or over 500V in the first 5 s in PFC star period.
voltage is normal in the first 5 s in PFC star period.
EF
No
No
Waiting for 220V power supply
No
stable
Yes
Power supply is abnormal