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SiUS341615E
Troubleshooting by Error Code
Service Diagnosis
266
3.58 Transmission Error between Indoor Units and Outdoor
Units
Error Code
U4
Applicable
Models
All indoor unit models
All outdoor unit models
Method of Error
Detection
Microcomputer checks if transmission between indoor and outdoor units is normal.
Error Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Short circuit in indoor-outdoor or outdoor-outdoor transmission wiring (F1 / F2), or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective indoor unit PCB
Defective outdoor unit PCB
Troubleshooting
Do all
indoor unit
remote controllers in
the same refrigerant
system display
U4
?
Are the
indoor-outdoor and
outdoor-outdoor
transmission wirings
normal?
Has the
indoor or
outdoor unit PCB
been replaced, or has
the indoor-outdoor or
outdoor-outdoor
transmission
wiring been
modified?
U4-01
NO
YES
YES
Replace the indoor unit PCB.
Press and hold BS3 on the
master outdoor unit main
PCB for a period of 5
seconds or more. (The
system will not operate for a
period of 12 minutes at
maximum.)
Modify the transmission
wirings.
YES
Refer to
U4-03
troubleshooting.
(Indoor unit system
transmission error)
NO
NO
NO
YES
Reset the power supply once.
Check for details of error in
monitor mode.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
A
Содержание RXYQ-TA Series
Страница 1: ...Service Manual SiUS341615E RXYQ72 408TAYDU RXYQ72 408TATJU Heat Pump 60 Hz...
Страница 320: ...Wiring Diagrams SiUS341615E 307 Appendix 1 Wiring Diagrams 1 1 Outdoor Unit RXYQ72TAYDU 3D106438A...
Страница 321: ...SiUS341615E Wiring Diagrams Appendix 308 RXYQ96 120TAYDU 2D106439A...
Страница 322: ...Wiring Diagrams SiUS341615E 309 Appendix RXYQ144 168TAYDU 2D106440A...
Страница 323: ...SiUS341615E Wiring Diagrams Appendix 310 RXYQ72TATJU 3D106435A...
Страница 324: ...Wiring Diagrams SiUS341615E 311 Appendix RXYQ96 120TATJU 2D106436A...
Страница 325: ...SiUS341615E Wiring Diagrams Appendix 312 RXYQ144 168TATJU 2D106437A...
Страница 334: ...Wiring Diagrams SiUS341615E 321 Appendix 1 3 2 Energy Recovery Ventilator VAM Series VAM300 470 600GVJU 3D073269C...
Страница 335: ...SiUS341615E Wiring Diagrams Appendix 322 VAM1200GVJU 3D073270C...
Страница 336: ...Revision History Month Year Version Revised contents 02 2017 SiUS341615E First edition...