Fujitsu AO*G18LFC series, Service Instruction

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Trouble shooting 6
INDOOR UNIT
INDOOR UNIT Error Method:
Detective Actuators:
Detective details:
Forecast of Cause :
Check Point 2 :
62.9 103.3 134.2 176.0 233.2 312.3 579. 1131.9 Resistance Value (k )
Temperature
OK OK
OK
17.1 25.6 39.6 Resistance Value (k )
Temperature
Indoor Heat Ex. Thermistor Error
Indoor unit Controller PCB
Heat Ex. temperature thermistor When Heat Ex. Temperature Thermistor open or short-circuit is detected.
1. Connector connection failure 2.Thermistor failure 3. Controller PCB failure
Check Point 1 : Check connection of Connector
Check if connector is removed.
Check erroneous connection.
Check if thermistor cable is open.
>>Upon correcting the removed connector or mis-wiring, reset the power.
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Approx. value)
If Thermistor is either open or shorted, replace it and reset the power.
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of indoor unit and check terminal voltage at Thermistor (DC5.0V)
If the voltage does not appear, replace Controller PCB.
02-09
20°C 10°C 5°C 0°C -5°C -10°C -20°C -30°C
50°C
11.6
60°C
10.4
63°C 40°C 30°C
THERMISTOR
(PIPE)
CN3
2
1 2
1
3
2
1 3
2
1
BLACK
BLACK
WHITE
RED
Indicate or Display:
Refer to error code table.