Read Panasonic CS-MZ20UD3EA Service Manual online
84
16.4.16 H97 (Outdoor 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.
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 outdoor unit PCB.
Troubleshooting
FAN MOTOR
CN-MTR2
(WHT)
10
1
W
MS
3
U
5
V
14
16
16
IC19
CN-MTR1
1
2
R105
1k
3
4
5
5V
R111
R120
1k
1k
+
C173
C175
0.01μ
0.01μ
50V
G5
G5
G5
C177
C176
0.01μ
0.01μ
50V
50V
G5
PCB BOARD
Replace fan motor.
Replace outdoor PCB.
Replace fan motor.
Replace fan motor.
Replace outdoor PCB.
Does it rotate?
Is the resistance normal?
Use an inverter check to check on
the power transistor on board.
Connect it to PCB’s CN-MRT2 port.
Turn power ON and run the unit.
the power transistor on board.
Connect it to PCB’s CN-MRT2 port.
Turn power ON and run the unit.
Do all 6 LED light turn ON and turn
OFF periodically?
OFF periodically?
Does the voltage at each terminal
becomes 5 and 0Vdc repeatedly?
becomes 5 and 0Vdc repeatedly?
U
NO
YES
V
W
NO
YES
NO
YES
NO
YES
When abnormality indication starts again
Turn off power supply and rotate fan by
hand.
hand.
Caution
For safety reason and to prevent
component breakdown, always switch
off the power before remove and
connect the component.
component breakdown, always switch
off the power before remove and
connect the component.
Does fan rotate smoothly?
NO
Replace fan motor.
YES
Turn power supply on and operate fan.
Turn off power supply and
disconnect fan motor CN-MRT2
connector.
disconnect fan motor CN-MRT2
connector.
Check resistance of the motor.
Measure at fan motor connector
CN-MRT1 (1-2, 1-3, 2-3).
Measure at fan motor connector
CN-MRT1 (1-2, 1-3, 2-3).
Stop the fan motor
Check the rotation feedback output from
fan motor’s CN-MTR1 output.
Rotate the fan motor manually (by hand)
while measure the voltage at PCB’s
CN-MRT1
- Between 1(+) and 5(-)
- Between 1(+) and 5(-)
- Between 2(+) and 5(-)
- Between 3(+) and 5(-)
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