Service Diagnosis
37
Domestic air conditioner
11.4.3 Indoor AC fan motor malfunction
Indoor Display E14
Method of
The rotation speed detected by the Hall IC during fan motor operation is
used to determine
Malfunction abnormal fan motor operation
Detection
Malfunction when the detected rotation feedback signal don’t received in 2 minutes
Decision
Conditions
Supposed
■
Operation halt due to breaking of wire inside the fan motor.
Causes
■
Fan motor overheat protection
■
Operation halt due to breaking of the fan motor lead wires
■
Detection error due to faulty indoor unit PCB
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect
connector, or else parts damage may be occurred.
Check whether terminals
on indoor pcb is well?
Electrify the machine again and turn it on in the cooling operation,
Measure voltage between the positions 1and 3 of Terminal CN5 on
the indoor PCB
the voltage is about 90-220vac
check whether motor can run
when turn on the unit
the indoor motor is damaged and need replace
Yes
NO
NO
Yes
Measure whether there is voltage pulse(0-5VDC)
between the positions middle wire and black wire
of Terminal CN2 on the indoor PCB
NO
the indoor pcb is damaged and need replace
Pull out the terminals on the indoor
mainboard and reinsert them.
No
Yes
Is it ok?
Yes
