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SiUS372201EA
Troubleshooting by Error Code
Part 6 Service Diagnosis
394
3.67 Transmission Error between Indoor Units and Outdoor
Units, Open Phase in Power Supply Wiring
Applicable
Models
All indoor unit models
All outdoor unit models
Error Code
U4
Method of Error
Detection
Microcomputer checks if transmission between indoor and outdoor units is normal.
Error Decision
Conditions
Transmission is not carried out normally for a certain amount of time.
Supposed
Causes
Open phase in power supply wiring
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 control PCB
Defective outdoor unit main PCB
Multi-tenant function is ON.
Summary of Contents for REYQ-AATJA
Page 1: ...Service Manual Heat Recovery 60 Hz REYQ AATJA 208 230 V REYQ AAYDA 460 V SiUS372201EA...
Page 465: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 458 BS6 8Q54TVJ 2D089122B...
Page 466: ...Wiring Diagrams SiUS372201EA 459 Part 7 Appendix BS10 12Q54TVJ 2D089121B...
Page 469: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 462 BSF6 8Q54TVJ 2D123905A...
Page 472: ...Wiring Diagrams SiUS372201EA 465 Part 7 Appendix FXZQ05 07 09 12 15 18TAVJU 3D110443A...
Page 476: ...Wiring Diagrams SiUS372201EA 469 Part 7 Appendix FXEQ07 09 12 15 18 24PVJU 3D098557A...
Page 477: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 470 FXDQ07 09 12 18 24MVJU C 3D050501C...
Page 483: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 476 FXHQ12 24 36MVJU 3D048116C...
Page 484: ...Wiring Diagrams SiUS372201EA 477 Part 7 Appendix FXAQ07 09 12 18 24PVJU 3D075354F...
Page 490: ...Wiring Diagrams SiUS372201EA 483 Part 7 Appendix VAM1200GVJU 3D073270D...