Si20-701_B
Troubleshooting by Remote Controller
474
Check for Factors Causing Wet Operation
Referring to the Fault Tree Analysis (FTA) shown below,
identify the defective points.
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.)
CHECK 9
←
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?
Defective
valve coil
Defective
valve body
Defective low
pressure
sensor
Defective
suction pipe
thermistor
Defective
control PCB
Defective electronic
expansion valve
Defective control
Defective
superheated
degree control
Wet
operation
Defective crankcase
heater
Frequent starts and
stops of the compressor
Refrigerant
dwelling
Excessive refrigerant
charging
←
Refer to
CHECK 10
Dirty evaporator
Decreased
evaporation
capacity
Decreased
fan airflow
rate
Defective
fan motor
Defective
control
PCB
(including
capacity
setting)
Decreased
fan output
←
Is the heat exchanger
clogged?
←
Can the fan motor
be rotated with
hands?
Are the motor coil
resistance and
insulation normal?