Fujitsu AB*G30LRTE series, Service Instruction

Page: 35 / 71

Detective Actuators:
Indoor unit Controller PCB
Room temperature thermistor
Detective details:
Room temperature thermistor is open or short is detected always.
Forecast of Cause : 1. Connector failure connection 2. Thermistor failure 3. Controller PCB failure
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Rough value)
If Thermistor is either open or shorted, replace it and reset the power.
Check Point 1 : Check connection of Connector
Check if connector is loose or removed
Check erroneous connection
Check if thermistor cable is open
>>Reset Power when reinstalling due to removed connector or incorrect wiring.
6.5 8.0
10.0 12.5 15.8 20.2 25.9 33.6
4.3 5.3 Resistance value (k )
OK
OK
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
If the voltage does not appear, replace Controller PCB and execute the check operation again.
02-08
Trouble shooting 6
INDOOR UNIT Error Method:
Indicate or Display:
Indoor Room Thermistor Error
Refer to error code table.
Temperature (°C )
Temperature (°C )
0
40 45
5
44.0
-5 10
58.2
-10 15 20 25
30 35
Resistance value (k )
H/E (MID) Thermistor
Room Temp. Thermistor
AR*G30/ 36LMLE
BLACK
BLACK
1
2
1
2
1 1
2 2
1 1
2 2
CN5
CN8
GRAY
GRAY
1
2
CN7
H/E (MID) Thermistor
Room Temp. Thermistor
AU*G30/ 36LRLE
RED
RED
1
2
1
2
1 1
2 2
CN5
CN8
BLACK
BLACK
1
2
CN7
1
2
1
2
1
2
1
2
1
2
H/E (MID) Thermistor
Room Temp. Thermistor
BLACK
BLACK
CN5
CN8
GRAY
GRAY
CN7
BLACK
BLACK
AB*G30/ 36LRTE