Fujitsu AS*A09LKC Service Instructions Manual page 32

Trouble shooting 8
OUTDOOR UNIT Error Method:
Outdoor Temperature Thermistor Error
Detective Actuators:
Outdoor Unit Inverter PCB
Outdoor Temperature Thermistor
Forecast of Cause :
1. Connector connection 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.
OK OK
Check Point 2 : Remove connector and check thermistor resistance value
Thermistor characteristics (Approx. value)
Temperature (°C )
Resistance value (k )
Temperature (°C )
Resistance value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK OK
Check Point 3 : Check voltage of Inverter PCB (DC5.0V)
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor (DC5.0V)
AO*R09LKC
BLACK
1 1
BLACK
2 2
BLACK
3 3
BLACK
4 4
BLACK
1 1
2 2
BLACK
3 3
If the voltage does not appear, replace
Indicate or Display:
Refer to error code table.
Detective details:
When Outdoor Temperature Thermistor open or short-circuit
is detected at power ON or while running the compressor.
2. Thermistor failure
-20 -10 -5
115 62.3 46.6
30 40 50
7.97 5.18 3.45
THERMISTOR
( HEAT EXCHANGER )
THERMISTOR
( DISCHARGE PIPE )
THERMISTOR
( OUTDOOR TEMP. )
Inverter PCB
3. Inverter PCB failure
0 5 10 15
35.2 26.9 20.7 16.1
60 70
2.36 1.65
AO*R12LKC
BLACK
1 1
BLACK
2 2
BLACK
3 3
BLACK
4 4
BLACK
1 1
2 2
BLACK
3 3
.
02-10
20
12.6
THERMISTOR
( HEAT EXCHANGER )
THERMISTOR
( DISCHARGE PIPE )
THERMISTOR
( OUTDOOR TEMP. )