30
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/liquid(TH2)
Condenser/evaporator temperature
thermistor(TH5)
Thermistor R
0
=15k
"
± 3%
Fixed number of B=3480
± 2%
Rt=15exp { 3480( ) }
0
:
15 k
"
10
:
9.6 k
"
20
:
6.3 k
"
25
:
5.4 k
"
30
:
4.3 k
"
40
:
3.0 k
"
Thermistor for
lower temperature
1
273+t
1
273
9-6-1. Thermistor
9-6-2. DC Fan motor (FAN MOTOR/ INDOOR CONTROLLER BOARD)
Indoor controller board fuse check
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 to the indoor controller circuit
board and fan motor.)
Self check
Symptom : The indoor fan cannot rotate.
1
2
Wiring contact check
Contact of fan motor connector (CNMF)
No
No
NG
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit
board.
TEST POINT
1
: V
DC
(between 1 (+) and 4 (-) of the fan connector): V
DC
DC 310~340 V
TEST POINT
2
: V
CC
(between 5 (+) and 4 (-) of the fan connector): V
CC
DC 15 V
Wiring recovery
Replace the drain pump.
Replace indoor controller board.
Replace the fan motor.
Replace indoor
controller board
Replace the fan motor.
Is the voltage normal?
Is there contact failure?
No
Yes
Yes
No
Yes
Check the operation of fan.
END
NG
OK
END
OK
Check the operation
Check method of DC fan motor (fan motor / indoor controller circuit board)
Is the fuse normal?
Yes
Is the resistance
between the terminals of
drain pump normal?
Replace the fan motor.
Replace the indoor controller board.
OCH551A
