Fujitsu AIRSTAGE V-II - Page 75

Thermistor Characteristics (Rough value)
If Thermistor is either open or shorted, replace it and reset the power.
Trouble shooting 5
INDOOR UNIT Error Method:
Heat Exchanger Inlet Sensor Error
Indicate or Display:
Indoor Unit : Operation LED 4 times Flash, Timer LED 2 Times Flash,
Filter LED Continuous Flash.
Outdoor Unit : E.5 U.1
Error Code : 4 2
Detective Actuators:
Indoor Unit Controller PCB Circuit
Heat Exchanger Inlet Thermistor
Detective details:
When open or shorted Heat Exchanger Inlet Thermistor is detected
at Power ON.
Resistance Value ( )
Temperature (°C)
32.4
35
40.0
30
49.862.579.1100.9129.8168.6
2520151050
Resistance Value ( )
Temperature (°C)
17.821.226.3
504540
OK
Forecast of Cause :
1. Connector defective connection 2. Thermistor 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 Thermistor resistance value
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
Small size Wall mount Schematic Diagram(Direct soldering to PCB)
If the voltage does not appear, replace Controller PCB and set up the original address.
(Refer to 06-03 page Main PCB removal.)
H/E Inlet Thermistor
(CN20 Wire:Black)
H/E Outlet Thermistor
(CN20 Wire:Gray)
Room Temp. Thermistor
(CN19 Wire:Black)
Room Temp. Thermistor
(CN10 Wire:Black)
H/E Intlet Thermistor
(CN12 Wire:Black)
H/E Outlet Thermistor
(CN11 Wire:Gray)
04-14
DC
Cassette Schematic Diagram (Connector connection)
Wall mount Schematic Diagram (Connector connection)
H/E Outlet Thermistor
(CN9 Wire:Gray)
H/E Inlet Thermistor
(CN9 Wire:Black)
Room Temp. Thermistor
(CN8 Wire:Black)
H/E Outlet Thermistor
(CN17 Wire:Gray)
H/E Inlet Thermistor
(CN17 Wire:Black)
Room Temp. Thermistor
(CN16 Wire:Black)
Duct Schematic Diagram (Connector connection)