Midea ATOM B Series Service Manual page 62

2.13 F1: DC bus voltage protection (for all models)
2.13.1 Digital display output
F1
2.13.2 Description
 F1 indicates DC bus voltage protection.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.13.3 Trigger / recover condition
 Trigger condition: If IC55 main chip couldn't receive the DC
first 5 seconds period when power on, it would report F1 and the big relay is forbid to close
 Recover condition: IC55 main chip can receive the DC
 Reset method: Resume automatically.
2.13.4 Possible causes
 DC fan motor damaged.
 The wire connect CN52 with CN53 is loose (36/42 model can ignore this reason for there's not this wire
connection).
 Main control board damaged.
 Filter board damaged (36/42 model can ignore this reason for they don't have a filter board).
2.13.5 Procedure
Check LED301 Is
Check the wiring between main control
board and filter board is correct or not.
Voltage of power supply is 166-265V?
F1
flashing or not
Yes
Yes
Atom B Series VRF 50/60Hz
bus voltage detection signal or the voltage less than 200VDC in the
.
bus voltage detection signal and the voltage over 200V DC
No
Replace outdoor main PCB
No
Connect again
Provide normal power supply
No
.
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