Basic Control
Si18-525B
112
Function
2.3
Electronic Expansion Valve PI Control
Main Electronic Expansion Valve EV1 Control
Carries out the electronic expansion valve (Y1E) PI control to maintain the evaporator outlet
superheated degree (SH) at constant during heating operation to make maximum use of the
outdoor unit heat exchanger (evaporator).
The optimum initial value of the evaporator outlet superheated degree is 5°C, but varies
depending on the discharge pipe superheated degree of inverter compressor.
Subcooling Electronic Expansion Valve EV2 Control
Makes PI control of the electronic expansion valve (Y2E) 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 = Ts - Te
SH : Evaporator outlet superheated degree (°C)
Ts : Suction pipe temperature detected by thermistor
R2T (°C)
Te : Low pressure equivalent saturation temperature
(°C)
SH = Tsh
-Te
SH : Outlet superheated degree of evaporator (
°
C)
Tsh : Suction pipe temperature detected with the
thermistor R5T (
°
C)
Te : Low pressure equivalent saturation temperature
(
°
C)
Summary of Contents for D-Series
Page 1: ...Si18 525B Applied Models Super Multi Plus Cooling only Super Multi Plus Heat Pump D Series ...
Page 33: ...List of Functions Si18 525B 20 List of Functions ...
Page 71: ...Specifications Si18 525B 58 Specifications ...
Page 117: ...Refrigerant Flow for Each Operation Mode Si18 525B 104 Refrigerant Circuit ...
Page 171: ...Indoor Unit SkyAir Models Si18 525B 158 Function ...
Page 207: ...Test Operation and Field Setting for RA Indoor Unit Si18 525B 194 Test Operation ...
Page 336: ...Si18 525B Service Check Function Troubleshooting 323 ...
Page 469: ...Wiring Diagrams Si18 525B 456 Appendix ...
Page 475: ...Si18 525B vi Index ...