Fujitsu AUXB04GALH Service Manual page 167

Trouble shooting 82
INDOOR UNIT Error Method:
Indoor unit suction air temp.
thermistor error
Detective Actuators:
Indoor Unit Controller PCB Circuit
Suction air temp. thermistor
Forecast of Cause :
1. Connector defective connection
Check Point 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
Check Point 2 : Remove connector and check sensor resistance value
SensorCharacteristics (Rough value)
Temperature (
°F )
Temperature ( °C )
Resistance Value (
Temperature ( °F )
Temperature ( °C )
(
Resistance Value
If Thermistor is either open or shorted, replace it and reset the power.
OK
Check Point 3 : Check voltage CN9 of Controller PCB (DC5.0V)
If the voltage does not appear, replace Controller PCB and set up the original address.
E 4A.1
Indicate or Display:
Outdoor Unit : E.5 U.1
Error Code
Detective details:
When Indoor unit suction air temp. thermistor open or shortage is detected.
2. Thermistordefective
32 41 50
0 5 10
)
33.6 25.2 20.1
104 113 122
40 45 50
)
5.3 4.3 3.5
: 4 A, 4 A. 1
3. Controller PCB defective
59 68 77
15 20 25
15.8 12.5 10.0
04-91
86 95
30 35
8.0 6.5
DC