Fujitsu AB Series A18LATN, Service Instruction

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Trouble shooting 28
INDOOR UNIT Error Method:
Indicate or Display:
ERROR CODE : E : 2c
Detective Actuators: Detective details:
Forecast of Cause :
OK OK
OK OK
4-way valve error
Indoor Unit Controller PCB Circuit
Heat Exchanger Temperature Thermistor
Room Temperature Thermistor
4-way valve
When the indoor heat exchanger temperature is compared with
the room temperature, and either following condition is detected
continuously two times, the compressor stops.
1. Connector connection failure 2. Thermistor failure 3. Coil failure 4. 4-way valve failure
5. 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 3 : Check the solenoid coil and 4-way valve
Remove CN30 from PCB and check the resistance value of coil.
Resistance value is about 1.4k
>>If it is Open or abnormal resistance value, replace Solenoid Coil.
07-29
Outdoor Unit : No indication
Cooling or Dry operation
[Indoor heat exchanger temp.] - [Room temp.] > 10degC
Heating operation
[indoor heat exchanger temp.] - [room temp.] < -10degC
If the same operation is repeated 5 times,
the compressor stops permanently.
[ Solenoid coil ]
Check each piping temperature,
and the location of the valve by the temperature difference.
>>If the value location is not proper, replace 4-way valve.
[ 4-way valve ]
OK OK
Check Point 4 : Replace Controller PCB
If Check Point 1- 3 do not improve the symptom, replace Controller PCB.
Check Point 2 : Check Heat exchanger temp. thermistor and Room temp. thermistor
Isn’t it fallen off the holder?
Is there a cable pinched?
>> Check characteristics of thermistor (Refer to Trouble shooting 3, 4),
If defective, replace the thermistor