Fujitsu ASU30RLE Service Instruction page 61

Trouble shooting 22
OUTDOOR UNIT Error Method:
Outdoor Thermistor Error
Detective Actuators:
Outdoor temperature thermistor
Forecast of Cause:
1. Connector connection failure, open 2. Thermistor failure 3. Main 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
Thermistor Characteristics(Rough value)
Temperature (°C )
Temperature (°F )
Resistance value (k )
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
2 2
CN61
BLACK
3 3
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Indicate of Display:
Indoor Unit :
Operation lamp: 7 times Flash,
Timer lamp
ERROR CODE : [E : 74]
Detective details:
When Outdoor temperature thermistor open or short-circuit is detected
at power ON or while running compressor.
-30 -20 -10
-22 -4 14
224.33 115.24 62.28
60 70 80
140 158 176
2.36 1.65 1.65
Outdoor Temp. Thermistor
Outdoor unit :
: 4 times Flash
0 10 20
32 50 68
35.21 20.72 12.64
02-25
PUMP LOW
POWER
DOWN NOISE
ERROR
MODE (L1) (L2) (L3) (L4)
7 4
2
: Light OFF : Light ON n : n times blinking
30 40 50
86 104 122
7.97 5.18 3.45
PEAK
CUT
(L5) (L6)