Indoor Unit Heat Ex. Inlet Temp. Sensor Error; Check Voltage Of Controller Pcb (Dc5.0V) - Fujitsu Airstage VR-II Series Service Manual

Trouble shooting 22
INDOOR UNIT Error Method:
Indoor unit Heat Ex. inlet temp.
sensor Error
Detective Actuators:
Indoor Unit Controller PCB Circuit
Heat Exchanger Inlet temp. Sensor
Forecast of Cause : 1. Connector defective connection 2. Sensor defective 3. Controller PCB defective
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
Sensor Characteristics (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 of Controller PCB (DC5.0V)
Corresponding connector
Model Type
Duct type
Cassette type
Wall type
Floor/Ceilling type
Compact Wall type
If the voltage does not appear, replace Controller PCB and set up the original address.
Indicate or Display:
E42. 1
Outdoor Unit : E.5 U.1
Indoor Unit
Error Code
Detective details:
When open or shorted Heat Exchanger Inlet temp. sensor is detected
32 41 50
0 5 10
168.6 129.8 100.9
104 113 122
40 45 50
26.3 21.2 17.8
Heat Ex Inlet temp. Sensor (Black Wires)
CN9
CN20
: Operation LED 4 times Flash, Timer LED 2 Times Flash,
Filter LED Continuous Flash.
: 4 2
59 68 77
15 20 25
79.1 62.5 49.8
04-31
86 95
30 35
40.0 32.4
DC