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Troubleshooting (OP: Unified ON/OFF Controller)
SiUS34-801A_b
462
Troubleshooting
[CHECK 5] Check for causes of rise in high pressure
Referring to the Fault Tree Analysis (FTA) shown below, probe the faulty points.
Short circuit
Rise in high
pressure
Local
pressure
rise
High pipe
resistance
Stop valve closed
Bent or crashed pipe
Clogging of foreign
particles
←
Check to be sure the stop valve is open.
←
Conduct visual checks for pipe conditions.
←
Is there any temperature difference caused before
and after the filter or branch pipe.
[In cooling]
If the outdoor unit electronic
expansion valve is throttled:
(See *1.)
Faulty outdoor
unit motorized
valve
Faulty valve coil
Faulty valve body
←
Are the coil resistance and insulation normal?
A temperature difference in excess of 50
°
F
between the inlet and the outlet is deemed to be abnormal.
Faulty
control
Faulty high pressure sensor
Faulty control PC board
←
Are the electrical characteristics normal?
←
Is the pressure value checked with the Service Checker
corresponding to the measurement of the pressure sensor?
←
Are the coil resistance and insulation
normal?
Faulty high
pressure
control
Faulty indoor
unit motorized
valve
Faulty valve coil
Faulty valve body
[In heating]
If the indoor unit electronic
expansion valve excessively
throttled:
(See *2.)
Faulty
control
Faulty high pressure sensor
Faulty indoor unit
liquid pipe thermistor
Faulty control PC board
←
Are the electrical characteristics normal?
←
In 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
pressure sensor?
[In cooling]
High suction
air
temperature
of the
condenser
[In heating]
High suction air
temperature
of outdoor unit
Short circuit
High ambient temperature
←
Is the suction air temperature not more than
109.4
°
F?
←
Is the outdoor temperature not more than
109.4
°
F?
High suction
air temperature
of indoor unit
High ambient temperature
←
Is the suction air temperature not more than 80.6
°
F?
←
Is the indoor temperature not more than 80.6
°
F?
Faulty suction air thermistor of indoor unit
High suction air temperature of outdoor unit
Faulty outdoor temperature thermistor of outdoor unit
←
Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←
Is the outdoor temperature not more than 60.8
°
FWB?
←
Is the connector properly connected?
Are the thermistor resistance characteristics normal?
Degradation
in condensing
capacity
Dirty condenser
Mixing of non-condensable gas
←
Is the heat exchanger clogged? (In cooling)
←
Is air or else mixed in the refrigerant system?
Decreased
fan airflow
rate
Decreased
fan
output
Faulty fan
motor
←
Can the fan motor be rotated with hands?
Are the motor coil resistance and
insulation normal?
←
If a spare PC board is mounted, is the
capacity setting properly made?
Faulty control
PC board
(Including
capacity setting)
High air
passage
resistance
Dirty filter
←
Is the air filter clogged?
Obstacle
←
Is there any obstacle in the air passage?
Excessive refrigerant charging
Improper model selection [In heating]
←
Refer to P376.
←
Is the indoor unit too small compared to
the large-sized outdoor unit?
*1: In cooling, it is normal if the outdoor unit electronic expansion valve (EVM) is fully open.
*2: In heating, the indoor unit electronic expansion valve is used for “subcooled degree control”.
SDK04009
Summary of Contents for VRV III
Page 15: ...SiUS34 801A_b xiv ...
Page 23: ...Model Selection SiUS34 801A_b 8 General Information ...
Page 133: ...Field Settings SiUS34 801A_b 118 VRVIII R 410A Heat Pump 60Hz ...
Page 254: ...SiUS34 801A_b Test Operation VRVIII R 410A Heat Recovery 60Hz 239 R 410A Label R 410A Label ...
Page 329: ...Field Setting SiUS34 801A_b 314 Indoor Unit ...
Page 340: ...SiUS34 801A_b Troubleshooting by Remote Controller Troubleshooting 325 ...
Page 490: ...SiUS34 801A_b Piping Diagrams Appendix 475 Heat Pump 230V RXYQ72 96 120PTJU 3D058636A ...
Page 491: ...Piping Diagrams SiUS34 801A_b 476 Appendix Heat Pump 230V RXYQ144PTJU 3D058640 ...
Page 492: ...SiUS34 801A_b Piping Diagrams Appendix 477 Heat Recovery 460V REYQ72 96 120PYDN 3D058639A ...
Page 493: ...Piping Diagrams SiUS34 801A_b 478 Appendix Heat Recovery 460V REMQ72PYDN 3D058637A ...
Page 494: ...SiUS34 801A_b Piping Diagrams Appendix 479 Heat Recovery 460V REMQ96 120PYDN 3D058638A ...
Page 495: ...Piping Diagrams SiUS34 801A_b 480 Appendix Heat Recovery 230V REYQ72 96 120PTJU 3D058639A ...
Page 496: ...SiUS34 801A_b Piping Diagrams Appendix 481 Heat Recovery 230V REYQ144PTJU 3D058640 ...
Page 497: ...Piping Diagrams SiUS34 801A_b 482 Appendix Heat Recovery 230V REMQ72PTJU 3D058637A ...
Page 498: ...SiUS34 801A_b Piping Diagrams Appendix 483 Heat Recovery 230V REMQ96 120PTJU 3D058638A ...
Page 501: ...Piping Diagrams SiUS34 801A_b 486 Appendix 1 3 BS Unit 4D057985A ...
Page 537: ...Piping Installation Point SiUS34 801A_b 522 Appendix ...
Page 543: ...Pressure Sensor SiUS34 801A_b 528 Appendix ...
Page 563: ...SiUS34 801A_b iv Index ...