Panasonic CS-E12RB4UW Service Manual page 66

15.4.6 H19 (Indoor Fan Motor – DC Motor Mechanism Locked)
Malfunction Decision Conditions

The rotation speed detected by the Hall IC during fan motor operation is used to determine abnormal fan motor
(feedback of rotation > 2550rpm or < 50rpm)
Malfunction Caused

Operation stops due to short circuit inside the fan motor winding.

Operation stops due to breaking of wire inside the fan motor.

Operation stops due to breaking of fan motor lead wires.

Operation stops due to Hall IC malfunction.

Operation error due to faulty indoor unit PCB.
Troubleshooting
When abnormality indication starts again.
Turn off power supply and rotate fan by hand.
Does fan rotate smoothly?
Turn power supply on and operate fan.
Does it rotate?
Turn off power supply and disconnect fan motor connector,
then turn power on.
Check the output of fan motor from indoor PCB.
Is the motor power supply voltage ~325Vdc (pin 1 & 4)
generated?
Is the motor control voltage 15Vdc (pin 5 & 4) generated?
Operate the fan, is the rotation command voltage 1~5Vdc (pin 6
& 4) generated?
YES
NO
YES
For safety reason and to prevent
component breakdown, always switch
Caution off the power before remove and
connect the component.
NO
• Replace fan motor.
YES
Stop fan motor.
Check the rotation feedback output from fan motor.
Rotate the fan motor by hand, is the rotation feedback
voltage 15Vdc (pin 7 & 4) generated?
NO
NO
NO
• Replace indoor PCB.
• Replace fan motor.
66
NO
YES