Daikin RZQ Series FCQ20EVA Service Manual page 168

Troubleshooting by Remote Controller
CHECK 8
Check for Factors Causing Wet Operation
Referring to the Fault Tree Analysis (FTA) shown below, identify the defective points.
Refrigerant
dwelling
Excessive refrigerant charging
Defective superheat
degree control
Wet operation
Decreased
evaporation
capacity
Note:
: Reference values for superheated degree to be used in the judgement of wet operation
1 Suction pipe superheated degree: 4°C or more 2 Discharge pipe superheated degree: 5°C or less
(The values above must be used only for reference purposes. Even it is operated within the range above,
operation may be normal in other conditions.)
159
Defective crankcase heater
Frequent starts and stops of the compressor
Defective valve coil
Defective electronic
expansion valve
Defective valve body
Defective low pressure sensor
Defective suction pipe thermistor
Defective control
Defective control PCB
Dirty evaporator
← Is the heat exchanger clogged?
Decreased
Decreased
fan airflow
fan output
rate
← Refer to
← Are the coil resistance
and insulation normal?
← Are the voltage characteristics normal?
← Is the connector properly connected?
Are the thermistor resistance
characteristics normal?
← Is the pressure value checked with
the Service Checker corresponding
to the measurement of the sensor?
← Can the fan motor be
Defective fan motor
rotated with hands?
Are the motor coil
resistance and insulation
Defective control
normal?
PCB (including
capacity setting)
SiME281501E
.
CHECK 9
Service Diagnosis