Fujitsu ASU7RLF1 Service Instructions Manual page 58

Trouble shooting 21
OUTDOOR UNIT Error Method:
3-Way Valve Thermistor Error
Detective Actuators:
Outdoor Unit Main PCB Circuit
3-way valve Temperature Thermistor
Forecast of Cause :
1. Connector connection failure 2.Thermistor failure 3. Main PCB 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 miss-wiring, reset the power.
OK OK
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Approx. value)
Temperature(°F)
Resistance Value (k )
Temperature(°F)
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)
M ake sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)
AOU18RLXFZH
VALVE THERMISTOR A, B
BLACK
1 1 1
WHITE RED
3 2 2
WHITE
4 3 3
WHITE YELLOW
4
5 4
CN39
WHITE
6 5 5
WHITE
WHITE BLUE
7 6 6
WHITE
8 7 7
WHITE BLACK
8
9 8
WHITE / WHITE
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Outdoor Unit :
Indoor Unit
ERROR CODE : [E : 76]
Detective details:
When 3-way valve Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.
14°F 23°F 32°F
312 233 176
104°F 122°F 140°F
25.6 17.1 11.6
2-WAY VALVE A
3-WAY VALVE A
2-WAY VALVE B
3-WAY VALVE B
LED 1 : 6 time Flash (for Indoor unit A)
LED 2 : 6 time Flash (for Indoor unit B)
LED 3 : 6 time Flash (for Indoor unit C)
: Operation lamp: 7 time Flash, Timer lamp: 6 time Flash
Economy lamp: Continuous flash.
41°F 50°F 59°F
134 103
80.3
158°F 176°F 194°F
8.12 5.78 4.19
AOU24RLXFZH
VALVE THERMISTOR A
BLACK BLACK
1 1 1
WHITE RED
3 2 2
WHITE
4 3 3
WHITE YELLOW
4
5 4
CN39
WHITE
6 5 5
WHITE
WHITE BLUE
7 6 6
WHITE
8 7 7
WHITE BLACK
8
9 8
WHITE / WHITE
VALVE THERMISTOR C
BLACK BLACK
1 1 1 1
RED GRAY
2
2 2
RED
4 4 3 3
RED BROWN
5 5 4 4
C CN40
RED
6 6 5 5
WHITE
RED
6 6 6
7 7
RED
7
8 8 7
RED
9 9 8 8
WHITE / RED
02-26
68°F 86°F
62.9 39.6
212°F
3.09
, B
2-WAY VALVE A 2-WAY VALVE A
3-WAY VALVE A 3-WAY VALVE A
2-WAY VALVE B 2-WAY VALVE B
3-WAY VALVE B 3-WAY VALVE B
2-WAY VALVE 2-WAY VALVE C
3-WAY VALVE 3-WAY VALVE C