Fujitsu ARC90LHTA - Page 40

Trouble shooting 7
OUTDOOR UNIT Error Method:
Indicate or Display:
Detective Actuators: Detective details:
Forecast of Cause :
OKOK
OKOK
Outdoor heat exchanger temperature
thermistor (outlet) error
Outdoor unit Main PCB
Heat exchanger temperature thermistor (Out)
When Heat exchanger temperature thermistor (out) open or
short-circuit is detected at power ON or while running the compressor.
1. Connector connection failure 2. Thermistor failure 3. Main PCB failure
Check Point 1 : Check connection of connector
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.
Check Point 2 : Remove connector and check thermistor resistance value
02-09
Refer to error code table.
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor (DC5.0V)
If the voltage does not appear, replace Main PCB.
CN141
CN143
CN144
THERMISTOR
( DISCHARGE PIPE )
THERMISTOR
( HEAT EXCHANGER OUT )
THERMISTOR
( OUTDOOR TEMP
. )
THERMISTOR
( COMPRESSOR TEMP
. )
1 2 1 2
5 6
3 4 5 6 3 4
1 2 3 4 1 2 3 4
1 2 3 1 2 3
Resistance value (k )
-30 -20 -10 0 10 20 30 40 50
60 70 80
Temperature (°C )
Resistance value (k )
Temperature (°C )
Thermistor characteristics (Approx. value)
If Thermistor is either open or shorted, replace it and reset the power.
95.6 50.3 27.8 16.1 9.6 6.0 3.8 2.5 1.7
1.2 0.8 0.6
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