Fujitsu AUG12LVLB - Indoor room thermistor error

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
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.
OK
OK
Trouble shooting 7
INDOOR UNIT Error Method:
Indicate or Display:
Indoor room thermistor error
Refer to error code table.
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.
H/E (MID) Thermistor
Room Temp. Thermistor
AU*G12/ 14/ 18LVLB
AR*G12/ 14/ 18LLTB
BLACK
BLACK
1
2
1
2
1 1
2 2
1 1
2 2
CN5
CN8
GRAY
GRAY
1
2
CN7
1
2
1
2
1
2
1
2
1
2
02-09
H/E (MID) Thermistor
Room Temp. Thermistor
BLACK
BLACK
CN5
CN8
GRAY
GRAY
CN7
BLACK
BLACK
AB*G18LVTB
DC
Thermistor Characteristics (Rough value)
If Thermistor is either open or shorted, replace it and reset the power.
6.5
35
8.0
30
10.012.515.820.225.933.6Resistance Value ( )
2520151050
58.2
-10
44.0
-5
Temperature (°C)
Resistance Value ( ) 4.35.3
4540
Temperature (°C)
AMP Air Conditioning
www.ampair.co.uk | sales@ampair.co.uk