Fujitsu AS*G09LTCB Service Instructions Manual page 43

Trouble shooting 12
OUTDOOR UNIT Error Method:
INDOOR UNIT
Discharge thermistor error
Detective Actuators:
Outdoor unit Main PCB
Discharge pipe temperature thermistor
Forecast of Cause :
1. Connector connection failure
Check Point 1 : Check connection of Connector
Check if connector is removed.
Check erroneous connection.
Check if thermistor cable is open.
>>Upon correcting the removed connector or mis-wiring, reset the power.
OK OK
Check Point 2 : Remove connector and check Thermistor resistance value Check Point 2 :
Thermistor Characteristics (Approx. value)
Temperature
Resistance Value (k )
Temperature
Resistance Value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK OK
Check Point 3 : Check voltage of Main PCB (DC5.0V) Check Point 3 :
Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)
AO*G09/ 12LTCN
THERMISTOR
(PIPE)
BLACK
BLACK
BROWN
BROWN
THERMISTOR
(DISCHARGE)
THERMISTOR
(OUTDOOR)
BLACK
BLACK
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Refer to error code table.
Detective details:
When Discharge pipe temperature thermistor open or short-circuit
is detected at power ON or while running the compressor.
2.Thermistor failure
-30°C -20°C -10°C -5°C
1013.1 531.6 292.9 221.1
40°C 50°C 60°C 70°C
26.3 17.8 12.3
AO*G14LTCN
THERMISTOR
(PIPE)
1 1
2 2
CN71
3 3
4 4
THERMISTOR
(DISCHARGE)
THERMISTOR
(OUTDOOR)
1 1
CN70
2 2
3 3
3. Main PCB failure
0°C 5°C
10°C
168.6 129.8 100.9
80°C 90°C 100°C
8.7 6.3 4.6 3.4
BLACK
1 1
BLACK
2 2
BLACK
3 3
BLACK
4 4
BLACK
1 1
2 2
BLACK
3 3
02-16
20°C 30°C
62.5 40.0
110°C 120°C
2.6 2.0
CN61
CN62