Mitsubishi Electric PLFY-WP32VBM-E Technical & Service Manual page 18

8-1-1. Thermistor
<Thermistor characteristic graph>
Thermistor for
Room temperature detection thermistor (TH21)
lower temperature
Pipe temperature detection thermistor/from HBC unit (TH22)
Pipe temperature detection thermistor/to HBC unit (TH23)
Thermistor R =15 kΩ ± 3%
0
Fixed number of B=3480 ± 2%
Rt=15exp { 3480(
1
273+t
0: 15 kΩ
10: 9.6 kΩ
20: 6.3 kΩ
5.4 kΩ
25:
30: 4.3 kΩ
40: 3.0 kΩ
8-1-2. DC an motor (fan motor/indoor controller board)
Check method of indoor fan motor (fan motor/indoor controller 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 board and fan motor.)
Self check
2
Conditions : The indoor fan cannot rotate.
Indoor controller board fuse check
Is the fuse normal?
Yes
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
TEST POINT 1 : V (between 1 (+) and 4 (−) of the fan connector): V
DC
TEST POINT 2 : V
(between 5 (+) and 4 (−) of the fan connector): V
CC
Is the voltage normal?
No
Replace the indoor
controller board
Check the operation.
Fail
Replace the fan motor.
OCH586
) }
1
273
Is the resistance
between the terminals of
drain pump normal?
Replace the drain pump.
Yes
Wiring recovery
board.
Yes
Replace the fan motor.
Check the operation of fan.
Replace the indoor controller board.
OK
END
< Thermistor for lower temperature >
50
40
30
20
10
0
-20 -10
No
310–340 V DC
DC
15 V DC
CC
OK
END
Fail
18
0 10 20 30 40 50
Temperature (:)
Replace the fan motor.
Replace the indoor controller board.