Fujitsu ASU30RLE Service Instruction page 50

Trouble shooting 11
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
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
Thermistor Characteristics(Rough value)
Temperature (°C )
Temperature (°F )
Resistance value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK
Test 3 : Check Voltage of Controller PCB (DC 5.0V)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
BLACK
1 1
BLACK
2 2
CN1
BLACK
3 3
BLACK
4 4
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Indicate of Display:
Indoor Unit :
Operation lamp: 4 times Flash,
Timer lamp
ERROR CODE : [E : 41]
Detective details:
Room temperature thermistor is open or short is detected always.
2. Thermistor failure 3. Controller PCB failure
-10 0 10
14 32 50
58.25 33.62 20.17 12.54
Pipe Temp. Thermistor
Room Temp. Thermistor
Outdoor unit :
POWER
MODE
: 1 times Flash
20 30 40
68 86 104 113
8.04 5.30 4.35
02-14
PUMP LOW
DOWN NOISE
ERROR
(L1) (L2) (L3) (L4)
5 15
2
: Light OFF : Light ON n : n times blinking
45
PEAK
CUT
(L5) (L6)