Basic Control
SiUS281811EA
108
Part 4 Functions and Control
2.3 Electronic Expansion Valve PI Control
Main Electronic Expansion Valve Control
Carries out main electronic expansion valve (Y1E) PI control to maintain the evaporator outlet
superheated degree (SH) at constant during heating operation, thus making maximum use of the
outdoor heat exchanger (evaporator).
The optimum initial value of the evaporator outlet superheated degree is 3
°
C (5.4
°
F), but varies
depending on the discharge pipe superheated degree of inverter compressor.
Subcooling Electronic Expansion Valve Control
Carries out PI control of subcooling electronic expansion valve (Y3E) to keep the superheated
degree (SH) of the outlet gas pipe on the evaporator side for the full use of the subcooling heat
exchanger.
SH = Ts1 – Te
SH:
Ts1:
Te:
Evaporator outlet superheated degree
Suction pipe temperature detected by thermistor
R3T
Low pressure equivalent saturation temperature
SH = Tsh – Te
SH:
Tsh:
Te:
Evaporator outlet superheated degree
Subcooling heat exchanger gas pipe temperature
detected by thermistor R6T
Low pressure equivalent saturation temperature
Summary of Contents for SkyAir RZR-TA Series
Page 1: ...Service Manual Cooling Only 60 Hz Heat Pump 60 Hz RZR TA RZQ TA Series SiUS281811EA...
Page 202: ...SiUS281811EA 196 Part 6 Service Diagnosis 5 15 Fan Motor Connector Check for FTQ TA 311...
Page 323: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 317 RZR18 24TAVJUA RZQ18 24TAVJUA 3D124495...
Page 327: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 321 FHQ18 24 30PVJU FHQ36 42MVJU 3D048116C...
Page 328: ...Wiring Diagrams SiUS281811EA 322 Part 7 Appendix FAQ18 24TAVJU 3D114844B...
Page 329: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 323 FBQ18 24 30 36 42 48PVJU 3D065984J...