Fan Speed Has Been Out Of Control Diagnosis And Solution - Carrier 38MAQB12-1 Service Manual

DIAGNOSIS AND SOLUTION (CONT)
Fan speed has been out of control diagnosis and solution (E3/F5)
Error Code
Malfunction decision conditions
Supposed causes
Troubleshooting
Power off, then restart the
unit 2 minutes later
Shut off the power supply,
Rotate the fan by hand.
Check the fan motor wiring
Measure the voltage for the
fan motor from the main
Replace the fan motor
E3/F5
When indoor fan speed remains too low (300RPM) for certain time, the unit stops and the LED
displays the failure.
·Wiring mistake
·Fan ass'y faulty
·Fan motor faulty
·PCB faulty
Yes
Yes
Yes
PCB
Yes
No The unit operates normally.
No
Find the cause and resolve it.
Correct the connections.
No
No Replace the main PCB
No
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