Fujitsu R410A Service Instruction

Thermistor Characteristics (Rough value)
If Thermistor is either open or shorted, replace it and reset the power.
Indoor Unit Controller PCB
Heat Exchanger (MID) Thermistor
Indoor unit thermistor is open or short is detected always.
1. Connector failure connection 2. Thermistor failure 3. Controller PCB failure
Test 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
Test 2 : Remove connector and check Thermistor resistance value
OK
Test 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 and execute the check operation again.
Trouble shooting 7
INDOOR UNIT Error Method:
Indoor Heat Ex. Thermistor Error
31.7
95
39.6
86
49.762.980.3103.3134.2176.0
776859504132
Temperature (°F )
17.120.925.6Resistance value (k )
122113104
Temperature (°F )
Temperature (°C )
Temperature (°C )
0
40 45 50
5101520253035
Resistance value (k )
BLACK
BLACK
BLACK
BLACK
1
2
1
2
1
2
1
2
CN3
CN1
1
2
3
1
2
3
RED
WHITE
THERMISTOR
( ROOM TEMP. )
THERMISTOR
( PIPE TEMP. )
02-09
Indicate or Display:
Outdoor Unit : No indication
Indoor Unit : Operation lamp: 4 times Flash, Timer lamp: 2 times Flash
Economy lamp: Continuous flash.
ERROR CODE : [E : 42]
Detective Actuators: Detective details:
Forecast of Cause:

Fujitsu R410A Specifications

General

Brand	Fujitsu
Model	R410A
Category	Air Conditioner
Language	English