SiUS371901E
Basic Control
Functions and Control
114
5.4
Electronic Expansion Valve PI Control
Main electronic expansion valve EVM 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.
Subcooling electronic expansion valve EVT control
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.
SC = Tc – Tf
SC: Condenser outlet subcooling degree
Tc: High pressure equivalent saturated
temperature
Tf: Liquid pipe temperature detected by heat
exchanger liquid pipe thermistor R4T,
R5T
SH = Tg – Te
SH: Evaporator outlet superheating degree
Tg: Suction pipe temperature detected by
heat exchanger gas pipe thermistor R8T,
R9T
Te: Low pressure equivalent saturated
temperature
SH = Tsh – Tm
SH: Evaporator outlet superheating degree
Tsh: Suction pipe temperature detected by
the subcooling heat exchanger outlet
thermistor R5T
Tm: Low or middle pressure equivalent
saturated temperature
Summary of Contents for REYQ-XA
Page 1: ...Service Manual SiUS371901E REYQ72 456XATJU REYQ72 456XAYDU REYQ72 432XAYCU Heat Recovery 60 Hz...
Page 415: ...SiUS371901E Wiring Diagrams Appendix 402 REYQ144 168XATJU 2D119206A...
Page 416: ...Wiring Diagrams SiUS371901E 403 Appendix REYQ72 96 120XAYDU 2D119207B...
Page 417: ...SiUS371901E Wiring Diagrams Appendix 404 REYQ144 168XAYDU 2D119208B...
Page 418: ...Wiring Diagrams SiUS371901E 405 Appendix REYQ72 96 120 144 168XAYCU 2D119209A...
Page 421: ...SiUS371901E Wiring Diagrams Appendix 408 FXZQ05 07 09 12 15 18TAVJU 3D110443A...
Page 423: ...SiUS371901E Wiring Diagrams Appendix 410 FXEQ07 09 12 15 18 24PVJU 3D098557A...
Page 425: ...SiUS371901E Wiring Diagrams Appendix 412 FXSQ05 07 09 12 15 18 24 30 36 48 54TAVJU C 3D110467C...
Page 426: ...Wiring Diagrams SiUS371901E 413 Appendix FXMQ07 09 12 15 18 24 30 36 48 54PBVJU 3D093209B...
Page 428: ...Wiring Diagrams SiUS371901E 415 Appendix FXHQ12 24 36MVJU 3D048116C...
Page 429: ...SiUS371901E Wiring Diagrams Appendix 416 FXAQ07 09 12 18 24PVJU C 3D075354D...
Page 435: ...SiUS371901E Wiring Diagrams Appendix 422 VAM1200GVJU 3D073270D...
Page 437: ...SiUS371901E Wiring Diagrams Appendix 424 1 4 2 Multi Branch Selector Unit BS4Q54TVJ 3D089123B...
Page 438: ...Wiring Diagrams SiUS371901E 425 Appendix BS6 8Q54TVJ 2D089122B...
Page 439: ...SiUS371901E Wiring Diagrams Appendix 426 BS10 12Q54TVJ 2D089121B...
Page 440: ...Revision History Month Year Version Revised contents 04 2019 SiUS371901E First edition...