Fujitsu AS*G09LTCB Service Instructions Manual page 44

Trouble shooting 13
OUTDOOR UNIT Error Method:
Outdoor unit Heat Ex. sensor error
Detective Actuators:
Outdoor unit Main PCB
Heat exchanger 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 Point 3 : Check voltage of Main PCB (DC5.0V)
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 Heat exchanger 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
95.6 50.3 27.8 21.0
40°C 50°C 60°C 70°C
2.5 1.7 1.2 0.8
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
16.1 12.4 9.6
80°C
0.6
BLACK
1 1
BLACK
2 2
CN61
BLACK
3 3
BLACK
4 4
BLACK
1 1
CN62
2 2
BLACK
3 3
02-17
20°C 30°C
6.0 3.8