24
25
OCH724
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
< Thermistor for lower temperature >
Temperature (
:
)
Resistance (K
"
)
<Thermistor characteristic graph>
Room temperature thermistor (TH1)
Pipe temperature thermistor (TH2)
Condenser/evaporator temperature thermistor (TH5)
Thermistor R
0
=15 k
"
± 3%
Fixed number of B=3480 ± 2%
Rt=15exp { 3480( ) }
0°C
15 kΩ
10°C
9.6 kΩ
20°C
6.3 kΩ
25°C
5.4 kΩ
30°C
4.3 kΩ
40°C
3.0 kΩ
Thermistor for
lower temperature
1
273+t
1
273
9-5-1. Thermistor
9-5-2. DC Fan motor (FAN MOTOR/INDOOR CONTROLLER BOARD)
Check method of DC fan motor (fan motor/indoor controller board)
1. Notes
· High voltage is applied to the connector (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.)
2. Self check
Symptom: The indoor fan cannot rotate.
Yes
Yes
Yes
No
Fail
Fail
OK
OK
No
No
Indoor controller board fuse check
Wiring contact check
Contact of fan motor connector (CNMF)
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller board.
TEST POINT
1
: V
DC
(between 1 (+) and 4 (−) of the fan connector): V
DC
310-340 V DC
TEST POINT
2
: V
CC
(between 5 (+) and 4 (−) of the fan connector): V
CC
15 V DC
Is the fuse normal?
Is there contact failure?
Is the voltage normal?
Check the operation.
Complete.
Complete.
Check the operation of fan.
Is the resistance between the terminals
of LOUVER MOTOR normal?
Yes
No
Replace the defective fan motor.
Replace the indoor controller board.
Replace the LOUVER MOTOR.
Replace the fuse.
Correct the wiring.
Replace the defective fan motor.
Replace the defective fan motor.
Replace the indoor
controller board.
Replace the indoor controller board.
