Troubleshooting by Error Code
SiUS331604E
223
Service Diagnosis
Check for causes of drop in low pressure
Referring to the Fault Tree Analysis (FTA) shown below, probe the defective points.
Note:
∗
1: For details of compressor capacity control while in cooling, refer to Compressor PI control.
∗
2: The low pressure protection control includes low pressure protection control and hot gas bypass
control.
∗
3: In cooling, the indoor unit electronic expansion valve is used for superheated degree control.
∗
4: In heating, the outdoor unit electronic expansion valve is used for superheated degree control of
outdoor unit heat exchanger.
CHECK 2
Abnormally dropin
low pressure
(Low evaporating
temperature)
[In cooling]
(
∗
1.)
Defective
low pressure
control
Defective
compressor
capacity
control
Defective low pressure
sensor
Defective main PCB
Defective
low pressure
protection
control
Defective low pressure
sensor
Defective hot gas
solenoid valve
Defective main PCB
[In both cooling
and heating]
(
∗
2.)
[In cooling]
If the indoor unit
electronic
expansion valve is
throttled too much:
(
∗
3.)
Defective indoor
unit electronic
expansion valve
Defective valve coil
Defective valve body
Defective
control
Defective gas pipe
thermistor of indoor unit
Defective liquid pipe
thermistor of indoor unit
Defective main PCB
Defective outdoor
unit electronic
expansion valve
Defective valve coil
Defective valve body
[In heating]
If the outdoor unit
electronic
expansion valve
excessively
throttled:
(
∗
4.)
Defective
control
Defective low pressure
sensor
Defective suction pipe
thermistor
Defective main PCB
[In cooling]
Low suction air
temperature of
the evaporator
[In heating]
Low suction air
temperature of
indoor unit
Short circuit
Low room temperature
Defective suction air thermistor of indoor unit
Low suction air temperature of outdoor unit
Defective outdoor air temperature thermistor of outdoor unit
High pipe
resistance
Abnormal piping length
Bent or crashed pipe
Clogging of foreign materials
Stop valve closed
Less
circulation
quantity of
refrigerant
Degradation
in evaporating
capacity
Inadequate refrigerant quantity
Moisture choke
Dirty
evaporator
Decreased
airflow rate
Decreased
fan output
Defective fan motor
←
Can the fan motor be rotated with hands?
Are the motor coil resistance and insulation normal?
←
If a spare PCB is installed, is the
capacity setting properly made?
←
Is the air filter clogged?
←
Is there any obstacle in the airflow passage?
Defective main PCB
(Including capacity setting)
High
airflow
passage
resistance
Dirty filter
Obstacle
Defective electronic
expansion valve
control
←
Is the pressure value checked with the Service Checker
corresponding to the measurement value of the pressure sensor?
←
Are the voltage characteristics normal?
←
Is the pressure value checked with the Service Checker
corresponding to the measurement value of the pressure sensor?
←
Are the coil resistance and insulation normal?
←
Are the voltage characteristics normal?
←
Are the coil resistance and insulation normal?
←
Check for the thermistor resistance and connection.
←
Check for the thermistor resistance and connection.
←
Are the voltage characteristics normal?
←
Are the coil resistance and insulation normal?
←
Is the pressure value checked with the Service Checker
corresponding to the measurement value of the pressure sensor?
←
Check for the thermistor resistance and connection.
←
Is the suction air temperature less than 14˚C (57.2˚F)?
←
Is the room temperature less than 14˚C (57.2˚F)?
←
Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←
Is the outdoor air temperature less than –20˚C (–4˚F)?
←
Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←
Does the piping length fall in the permissible range?
←
Conduct visual checks for pipe conditions.
←
Is there any temperature difference caused before and
after the filter or branch pipe?
←
Refer to the
CHECK 7
.
←
Eliminate moisture by vacuum operation. (Refer to
CHECK 8
)
←
Is the heat exchanger clogged?
Summary of Contents for VRV IV-S RXTQ-TAVJU Series
Page 1: ...Service Manual SiUS331604E RXTQ36 48 60TAVJU Heat Pump 60 Hz...
Page 254: ...Wiring Diagrams SiUS331604E 241 Appendix RXTQ48TAVJU 3D100496A...
Page 255: ...SiUS331604E Wiring Diagrams Appendix 242 RXTQ60TAVJU 3D100497A...
Page 260: ...Wiring Diagrams SiUS331604E 247 Appendix FXEQ07 09 12 15 18 24PVJU C 3D098557...
Page 267: ...SiUS331604E Wiring Diagrams Appendix 254 FXTQ12 18 24 30 36 42 48 54PAVJU 3D065036G...
Page 270: ...Wiring Diagrams SiUS331604E 257 Appendix VAM1200GVJU 3D073270C...
Page 271: ...Revision History Month Year Version Revised contents 06 2016 SiUS331604E First edition...
