Special Control
SiUS371901EB
153
Part 4 Functions and Control
Note(s)
7.4 Outdoor
Unit
Rotation
In the case of multi outdoor unit system, this outdoor unit rotation prevents the compressor from
breaking down due to unbalanced oil level between outdoor units.
Details of outdoor unit rotation
In the case of multi outdoor unit system, each outdoor unit is given an operating priority for the
control.
The operating priority of outdoor units is changed by outdoor unit rotation. The outdoor unit rotation
prevents unbalanced oil level between outdoor units by eliminating the long stop of compressors
during partial load.
Timing of outdoor unit rotation
At the beginning of the startup control, or;
After oil return operation, or;
After defrost operation, or;
One of the outdoor units is stopped for 20 minutes or more (only in cooling).
Example) The following diagram shows outdoor unit rotation in combination of 3 outdoor units.
∗
Master unit, slave unit 1 and slave unit 2 in this section are the names for installation.
They are determined in installation work, and not changed thereafter. (These names are different
from master unit and slave unit for control.)
The outdoor unit connected the control wires (F1 and F2) for the indoor unit should be designated
as master unit.
Consequently, The LED display on the outdoor unit main PCB for master unit, slave unit 1 and
slave unit 2 do not change.
Normal control
Normal control
Normal control
Normal control
Master Slave 1 Slave 2
Master Slave 1 Slave 2
Master Slave 1 Slave 2
Master Slave 1 Slave 2
A
A
Startup control
Outdoor unit
rotation
Outdoor unit
rotation
Outdoor unit
rotation
Priority
1
Priority
1
Priority
2
Priority
2
Priority
3
Priority
3
Priority
1
Priority
2
Priority
3
Priority
3
Priority
1
Priority
2
Oil return operation
or defrost operation
Any of outdoor
unit stops for a
period of 20
minutes or more.
Summary of Contents for REYQ72-432XAYCU
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Page 461: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 454 FXZQ05 07 09 12 15 18TAVJU 3D110443A ...
Page 463: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 456 FXEQ07 09 12 15 18 24PVJU 3D098557A ...
Page 464: ...Wiring Diagrams SiUS371901EB 457 Part 7 Appendix FXDQ07 09 12 18 24MVJU C 3D050501C ...
Page 468: ...Wiring Diagrams SiUS371901EB 461 Part 7 Appendix FXHQ12 24 36MVJU 3D048116C ...
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Page 475: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 468 VAM1200GVJU 3D073270D ...
Page 478: ...Wiring Diagrams SiUS371901EB 471 Part 7 Appendix BS6 8Q54TVJ 2D089122B ...
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