Fujitsu WATERSTAGE WS A050DD6 Series Maintenance Document page 13

Split system single phase type
Clear 7: Discharge thermistor error
Hydraulic Unit LED: Green 7 flashes / Red 1 flash
Outdoor Unit LED: flash
Probable causes:
•
Misconnection.
•
Sensor failure.
•
Main PCB failure.
Check:
1. Check the sensor connection:
See if the connector has been disconnected.
-
See if the connection is correct.
-
Check for any damage on the sensor cable.
-
After solving the misconnection problem, switch the heat pump back on.
2. Remove the sensor and check its resistance value:
- Check the resistance value
Temperature (°C)
Resistance (kΩ)
Temperature (°C)
Resistance (kΩ)
- If the thermistor is faulty, replace it.
3. Check the electronic board voltage:
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor (DC5.0V)
WO*A060LDC
EXP VALVE
PIPE
DISCHARGE PIPE
OUTDOOR TEMP
- If there is no voltage, replace Main PCB.
Maintenance Document 1589-3
OK
0 5 10 15
169 130 101 79,1 62,6 40,0 26,3 17,8
60 70 80 90
12,3 8,7 6,3 4,6
OK
WO*A080LDC
COMPRESSOR
TEMP
20 30 40 50
100 120
3,4 2
COMPRESSOR
TEMP
EXP VALVE
OUTDOOR
TEMP
DISCHARGE
PIPE
PIPE
WO*A100LDT
EXP VALVE
COMPRESSOR
TEMP
OUTDOOR
TEMP
PIPE
DISCHARGE
PIPE
13