Mitsubishi Electric Mr. Slim PLA Series Service Manual page 29

9-6-1. Thermistor
"
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:
:
:
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:
9-6-2. DC Fan motor (FAN MOTOR/ INDOOR CONTROLLER BOARD)
Check method of DC fan motor (fan motor/ indoor controller circuit board)
1
Notes
· High voltage is applied to the connecter (CNMF) for the fan motor. Pay attention to the service.
· Do not pull out the connector (CNMF) for the motor with the power supply on.
(It causes trouble of the indoor controller circuit
2
Self check
Symptom : The indoor fan cannot rotate.
Check the fuse (FUSE) on indoor
controller board.
Did the fuse blow?
No
Wiring contact check
Contact of fan motor connector (CNMF)
Is there contact failure?
No
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit
1 :
TEST POINT V (between 1 (+) and 4 ( ) of the fan connector): V
DC
2 :
TEST POINT V (between 5 (+) and 4 ( ) of the fan connector): V
CC
Is the voltage normal?
No
Replace the indoor
controller board.
Check the operation.
NG
Replace the fan motor.
OCH581
"
"
"
"
"
"
board and fan motor.)
Check the drain pump (DP).
Yes
Is the resistance between
terminals normal?
No
Replace the drain pump (DP).
Wiring recovery
Yes
board.
Replace the fan motor.
Yes
Check the operation of fan.
Replace the indoor controller board.
OK
END
<Thermistor for lower temperature>
50
40
30
20
10
0
20 10 0 10 20 30 40 50
4
Replace the indoor controller board (I.B).
Yes
Replace the fan motor (MF).
294–325 V DC
DC
15 V DC
CC
Yes OK
END
NG
:
14 32 50 68 86 104122 °F
Temperature