Fujitsu ASU30RLE Service Instruction page 59

Trouble shooting 20
OUTDOOR UNIT Error Method:
Heat Ex. Middle Temp.
Thernistor Error
Detective Actuators:
Heat ex. middle temp. 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
BLACK
2 2
CN63 3 3
BLACK
4 4
BLACK
5 5
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 : 73]
Detective details:
When Heat exchanger middle temperature thermistor open or short-circuit is
detected at power ON or while running compressor.
-30 -20 -10
-22 -4 14
95.58 50.31 27.81
60 70 80
140 158 176
1.19 0.84 0.61
Pipe (Liquid) Temp. Thermistor
Pipe (Mid) Temp. Thermistor
: 3 times Flash
0 10 20
32 50 68
16.05 103.34 9.63
90
194
0.45
02-23
Outdoor unit :
PUMP LOW
POWER
DOWN NOISE
ERROR
(L1) (L2) (L3)
MODE
13
7
2
: Light OFF : Light ON n : n times blinking
30 40 50
86 104 122
3.84 2.53 1.71
PEAK
CUT
(L4) (L5) (L6)