Service diagnosis
34 Domestic air conditioner
10.3.3 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
Electrif
●
y the machine again and turn it on in the cooling operation,
Measure voltage between the positions 1and 3 of Terminal CN
●
9
on the indoor PCB
the voltage is about 90
●
-220vac
check whether motor can run
●
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
NO
the indoor pcb is damaged and need replace
Pull out the terminals on the indoor
mainboard and reinsert them.
No
Yes
Yes