Indoor Room Thermistor Error - Fujitsu AOYG45LAT8 User Manual

Trouble shooting 10
INDOOR UNIT Error Method:

Indoor Room Thermistor Error

Detective Actuators:
Indoor Unit Controller PCB Circuit
Indoor Temperature Thermistor
Forecast of Cause : 1. Connector failure connection 2. Thermistor failure 3. Controller PCB failuer
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
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Rough value)
Temperature (°C)
Resistance Value ( )
Temperature (°C)
Resistance Value ( )
If Thermistor is either open or shorted, replace it and reset the power.
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)
Duct, Floor/Ceiling circuit diagram (Connector connection)
GRAY
1 1
CN5
GRAY
2 2
1
CN7
2
BLACK
1 1
CN8
BLACK
2 2
Cassette circuit diagram (Connector connection)
GRAY
1 1
CN5
GRAY
2 2
BLACK
1 1
CN8
BLACK
2 2
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Indicate or Display:
Outdoor Unit : E.5 U.1
Indoor Unit
Error Code
Detective details:
Indoor unit thermistor is open or short is detected always.
0 5 10
33.6 25.2 20.1
40 45 50
5.3 4.3 3.5
H/E (MID) Thermistor
Room Temp. Thermistor
H/E (MID) Thermistor
Room Temp. Thermistor
02-26
: Operation LED 4 times Flash, Timer LED 1 Times Flash,
Economy LED Continuous Flash.
: 4 1
15 20 25
15.8 12.5 10.0
Compact Wall mount circuit diagram(Connector connection)
BLACK
1 1
BLACK
2 2
CN4
BLACK
3 3
BLACK
4 4
Wall mount, Floor Scircuit diagram (Direct soldering to PCB)
RED
1
1
CN3
2
2 WHITE
3
BLACK
1
CN1
BLACK
2
30 35
8.0 6.5
DC
H/E Thermistor
Room Temp. Thermistor
H/E Thermistor
BLACK
1
2
BLACK
3
Room Temp. Thermistor