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SiUS331708EA
Troubleshooting by Error Code
Service Diagnosis
226
4.51 Transmission Error between Indoor Units and Outdoor
Unit
Error Code
U4
Applicable
Models
All indoor and outdoor units
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
Indoor to outdoor transmission wiring F1, F2 disconnection, short circuit or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective indoor unit PCB
Defective outdoor main PCB
Troubleshooting
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Caution
YES
NO
All indoor
unit remote
controllers of the same
refrigerant system
display
U4
.
Is the indoor-
outdoor transmission wiring
normal?
Has the indoor
or outdoor unit PCB
been replaced, or has the
indoor-outdoor unit
transmission wiring
been modified?
NO
YES
Replace the indoor unit PCB
indicated by the error code
U4
.
Fix the indoor-outdoor
unit transmission wiring.
NO
YES
Reset the power supply.
Press and hold the
RESET
(BS5)
button on the outdoor unit
PCB for 5 seconds.
∗
The unit will not operate for
up to 12 minutes.
A
Go to the next page.
Содержание RXSQ24TAVJU
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Страница 289: ...SiUS331708EA Wiring Diagrams Appendix 276 1 Wiring Diagrams 1 1 Outdoor Unit RXSQ24 36TAVJU 3D109545A...
Страница 290: ...Wiring Diagrams SiUS331708EA 277 Appendix RXSQ48TAVJU 3D109546A...
Страница 291: ...SiUS331708EA Wiring Diagrams Appendix 278 RXSQ60TAVJU 3D109547A...
Страница 292: ...Wiring Diagrams SiUS331708EA 279 Appendix 1 2 Indoor Unit FXFQ07 09 12 15 18 24 30 36 48TVJU 3D086460B...
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Страница 295: ...SiUS331708EA Wiring Diagrams Appendix 282 FXZQ05 07 09 12 15 18TAVJU 3D110443A...
Страница 298: ...Wiring Diagrams SiUS331708EA 285 Appendix FXEQ07 09 12 15 18 24PVJU 3D098557A...
Страница 300: ...Wiring Diagrams SiUS331708EA 287 Appendix FXSQ05 07 09 12 15 18 24 30 36 48 54TAVJU 3D110467B...
Страница 301: ...SiUS331708EA Wiring Diagrams Appendix 288 FXMQ07 09 12 15 18 24 30 36 48 54PBVJU 3D093209B...
Страница 302: ...Wiring Diagrams SiUS331708EA 289 Appendix FXHQ12 24 36MVJU 3D048116C...
Страница 303: ...SiUS331708EA Wiring Diagrams Appendix 290 FXAQ07 09 12 18 24PVJU 3D075354C...
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