Heat Exchanger Inlet Sensor Error - Fujitsu Airstage J-II Service Manual

Trouble shooting 5
INDOOR UNIT Error Method:

Heat Exchanger Inlet Sensor Error

Detective Actuators:
Indoor Unit Controller PCB Circuit
Heat Exchanger Inlet Thermistor
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
Thermistor Characteristics (Rough value)
Temperature (°C)
Resistance Value ( )
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)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
Duct Schematic Diagram (Connector connection)
Cassette Schematic Diagram (Connector connection)
H/E Inlet Thermistor
(CN9 Wire:Black)
H/E Outlet Thermistor
(CN9 Wire:Gray)
Room Temp. Thermistor
(CN8 Wire:Black)
If the voltage does not appear, replace Controller PCB and set up the original address.
Indicate or Display:
Outdoor Unit : E.5 U.1
Indoor Unit
Error Code
Detective details:
When open or shorted Heat Exchanger Inlet Thermistor is detected
at Power ON.
0 5 10
168.6 129.8 100.9
40 45 50
26.3 21.2 17.8
H/E Inlet Thermistor
(CN20 Wire:Black)
H/E Outlet Thermistor
(CN20 Wire:Gray)
Room Temp. Thermistor
(CN19 Wire:Black)
: Operation LED 4 times Flash, Timer LED 2 Times Flash,
Filter LED Continuous Flash.
: 4 2
15 20 25
79.1 62.5 49.8
Small size Wall mount Schematic Diagram(Direct soldering to PCB)
Wall mount Schematic Diagram (Connector connection)
H/E Inlet Thermistor
(CN17 Wire:Black)
H/E Outlet Thermistor
(CN17 Wire:Gray)
Room Temp. Thermistor
(CN16 Wire:Black)
04-15
30 35
40.0 32.4
DC
H/E Intlet Thermistor
(CN12 Wire:Black)
H/E Outlet Thermistor
(CN11 Wire:Gray)
Room Temp. Thermistor
(CN10 Wire:Black)