Basic Control
SiUS371901EB
139
Part 4 Functions and Control
5.4 Electronic Expansion Valve PI Control
When the outdoor unit heat exchanging is performed via the condenser (Y5S or Y6S is set to OFF),
this function is used to exert PI control on the electronic expansion valve (Y1E or Y3E) so that the
condenser outlet subcooling degree (SC) will become constant.
When the outdoor unit heat exchanging is performed via the evaporator (Y5S or Y6S is set to ON),
this function is used to exert PI control on the electronic expansion valve (Y1E or Y3E) so that the
evaporator outlet superheating degree (SH) will become constant.
In order to make the maximum use of the subcooling heat exchanger, this function is used to exert
PI control on the electronic expansion valve (Y2E, Y5E or Y3E) so that the evaporator-side gas
pipe superheating degree (SH) will become constant.
Main electronic expansion valve EVM control
SC = Tc – Tf
SC:
Tc:
Tf:
Condenser outlet subcooling degree
High pressure equivalent saturated
temperature
Liquid pipe temperature detected by heat
exchanger liquid pipe thermistor R4T,
R5T
SH = Tg – Te
SH:
Tg:
Te:
Evaporator outlet superheating degree
Suction pipe temperature detected by
heat exchanger gas pipe thermistor R8T,
R9T
Low pressure equivalent saturated
temperature
Subcooling electronic expansion valve EVT control
SH = Tsh – Tm
SH:
Tsh:
Tm:
Evaporator outlet superheating degree
Suction pipe temperature detected by
the subcooling heat exchanger outlet
thermistor R5T
Low or middle pressure equivalent
saturated temperature
Summary of Contents for REYQ72-432XAYCU
Page 455: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 448 REYQ144 168XATJU REYQ144 168XATJA 2D119206B ...
Page 457: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 450 REYQ144 168XAYDU REYQ144 168XAYDA 2D119208C ...
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 ...
Page 469: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 462 FXAQ07 09 12 18 24PVJU 3D075354F ...
Page 475: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 468 VAM1200GVJU 3D073270D ...
Page 478: ...Wiring Diagrams SiUS371901EB 471 Part 7 Appendix BS6 8Q54TVJ 2D089122B ...
Page 479: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 472 BS10 12Q54TVJ 2D089121B ...
Page 481: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 474 BSF6 8Q54TVJ 2D123905A ...