Fujitsu ARC90LHTA - Page 36

Trouble shooting 3
INDOOR UNIT Error Method:
Indicate or Display:
Detective Actuators: Detective details:
Forecast of Cause :
Check Point 2 : Remove connector and check thermistor resistance value
Check Point 1 : Check connection of connector
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
OK
OK
Temperature (°C )
Resistance value (k )
Temperature (°C )
Resistance value (k )
Indoor heat exchanger temperature
thermistor (middle) Error
Indoor unit controller PCB
Heat exchanger temperature
thermistor (middle)
When Heat exchanger temperature thermistor (middle) open or
short-circuit is detected at power ON.
1. Connector connection failure 2.Thermistor failure 3. Controller PCB failure
Check if connector is removed.
Check if connector is erroneous connection.
Check if thermistor cable is open.
>> Upon correcting the removed connector or mis-wiring, reset the power.
Thermistor characteristics (Approx. value)
If Thermistor is either open or shorted, replace it and reset the power.
Make sure circuit diagram of indoor unit and check terminal voltage at thermistor (DC5.0V)
If the voltage does not appear, replace Controller PCB.
02-05
Refer to error code table.
BLACK
BLACK
BLACK
BLACK
1
2
1
2
1 1
2 2
CN110
CN113
THERMISTOR
( ROOM TEMP. )
THERMISTOR
( PIPE-MID TEMP. )
-10 -5 0 5 10 15 20 30 40
50 60 70 80 90 100 110 120
312.3 233.2 176.0 134.2 103.3 80.3 62.9 39.6 25.6
17.1 11.6 8.1 5.8 4.2 3.1 2.3 1.8
AMP Air Conditioning
www.ampair.co.uk | sales@ampair.co.uk