Fujitsu AB*G14LVTA Service Instructions Manual page 61

Trouble shooting 21
OUTDOOR UNIT Error Method:
2-way valve thermistor error
Detective Actuators:
Outdoor unit Main PCB
2-way valve 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(°C)
Resistance Value (k )
Temperature(°C)
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)
BLACK
1 1 1
WHITE RED
3
2 2
WHITE
4 3
3
WHITE YELLOW
4
5 4
CN39
WHITE
5
6 5
WHITE BLUE
6 6
7
WHITE
8 7 7
WHITE BLACK
8 8
9
WHITE
BLACK
1 1 1
RED GRAY
2 2 2
RED
4 3 3
RED BROWN
5 4 4
CN40
RED
6 5 5
RED ORANGE
6 6
7
RED
8 7 7
GREEN
RED
9 8 8
RED
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Refer to error code table.
Detective details:
When the 2-way valve temperature thermistor open or short-circuit is
detected at power ON or while running the compressor.
2.Thermistor failure
-30 -20 -10
1131.9 579.6 312.3
50 60
17.1 11.6
VALVE THERMISTOR A, B
2-WAY VALVE A
3-WAY VALVE A
2-WAY VALVE B
3-WAY VALVE B
VALVE THERMISTOR D (For AO G30LAT4)
2-WAY VALVE C
3-WAY VALVE C
2-WAY VALVE D
3-WAY VALVE D
3. Main PCB failure
0 10
176.0 103.3
70 80
8.1 5.8
02-24
20 30 40
62.9 39.6 25.6