Mitsubishi Electric Mr.SLIM PCA Series, Руководство по обслуживанию, Страница: 25 / 44

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9-6-1. Thermistor
<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%
t( )Rt=15exp { 3480( ) }
0
10
20
25
30
40
Thermistor for
lower temperature
1
273+t
1
273
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
-4 -14 32 50 68 86 104122 °F
Temperature
Resistance (k
)
<Thermistor for lower temperature>
1
273+
1
273
T-32
1.8
°C
9-6-2. DC Fan motor (fan motor/indoor controller circuit board)
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
board and fan motor.)
Self check
Symptom : The indoor fan cannot turn around.
Yes
NG
NG
Wiring contact check
Contact of fan motor connector (CNMF)
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit
board.
TEST POINT : V
DC
(between 1 (+) and 4 (-) of the fan connector): V
DC
DC294~325V
TEST POINT
: V
CC
(between 5 (+) and 4 (-) of the fan connector): V
CC
DC15V
Wiring recovery
Replace the indoor controller board.
Replace the fan motor.
Replace the indoor
controller board.
Replace the fan motor.
Is the voltage normal?
Is there contact failure?
No
Yes
No
Check the operation of fan. END
Yes OK
Check the operation END
OK
Check method of DC fan motor (fan motor/indoor controller circuit board)
Sensor signal check
Measure the voltage between CNMF and DC 0V
and DC 15V in the indoor controller circuit board.
Does the voltage repeat
DC 0V and DC 15V?
No
Yes
Indoor controller board fuse check
Is the fuse blown?
Replace the indoor controller board.
Replace the fan motor.
Replace the drain pump.
Yes
Is the resistance between
terminals of drain pump is normal?
(When the drain pump (option)
is connected)
Yes
No
No
OCH501