Daikin VRV - WII Service Manual page 265

Troubleshooting (OP: Unified ON/OFF Controller)
[CHECK 4] Check for causes of wet operation
Referring to the Fault Tree Analysis (FTA) shown below, identify the faulty points.
Dwelled
refrigerant
Excessive refrigerant
charging
Faulty
superheated
degree control
[In heating]
If the outside unit
Wet operation
electronic
expansion valve
excessively
opened
(∗2)
Degradation in
evaporation
capacity
∗1 : In cooling, the indoor unit electronic expansion valve is used for "superheated degree control". (Refer to page 89.)
∗2 : In heating, the outside unit electronic expansion valve (Y1E) is used for "superheated degree control". (Refer to page
∗3 : Reference values for superheated degree to be used in the judgment of wet operation
252
Faulty crankcase heater
Frequent starts and
stops of the compressor
Faulty indoor
unit electronic
[In cooling] expansion valve
If the indoor unit
electronic
expansion valve
excessively
opened
Faulty control
(∗1)
Faulty outside
unit electronic
expansion valve
Faulty control
Dirty evaporator
[In cooling]
Decreased
fan airflow
rate
Dirty water heat exchanger
Decrease in
[In heating]
water of the
water heat
exchanger
67.)
Suction gas superheated degree: 37.4°F or less
excluding when it is immediately after startup, under drop control or other specific conditions.
(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.)
Faulty valve coil
Faulty valve body
Faulty gas pipe thermistor
of indoor unit
Faulty liquid pipe thermistor
of indoor unit
Faulty control PCB
Faulty valve coil
Faulty valve body
Faulty low pressure sensor
Faulty suction pipe thermistor
Faulty control PCB
← Is the heat exchanger clogged?
Faulty fan motor
Decreased
fan output
Faulty control PCB
(including capacity setting)
Dirty filter
High air
passage
resistance
Obstacle
Clogged water piping system
Faulty water pump
Discharge gas superheated degree: 59°F or less,
SiUS30-604
← Refer to [CHECK 5]
← Are the coil resistance and insulation normal?
← Is the connector properly connected?
Are the thermistor resistance characteristics
normal?
← Is the connector properly connected?
Are the thermistor resistance
characteristics normal?
← Are the coil resistance and insulation normal?
← Are the voltage characteristics normal?
← Is the connector properly connected?
Are the thermistor resistance characteristics normal?
← Does the pressure value of the Service Checker
match the reading of the pressure sensor?
← Can the fan motor be rotated with hands?
Are the motor coil resistance and
insulation normal?
← Is the air filter clogged?
← Is there any obstacle in the
air passage?
← Is the water heat exchanger clogged?
← Is the strainer or other parts clogged?
← Does the water pump function normally?
Troubleshooting