Special Control
SiUS34-907
40
Function
3.4
Pump Down Residual Operation
When activating compressor, if the liquid refrigerant remains in the heatexchanger, the liquid enters into the
compressor and dilutes oil therein resulting in decrease of lubricity.
Therefore, the pump down residual operation is performed to collect the refrigerant in the heatexchanger when
the compressor is down.
3.4.1 Pump Down Residual Operation in Cooling Operation
3.4.2 Pump Down Residual Operation in Heating Operation
Actuator
Pump down residual operation Step 1
Pump down residual operation Step 2
Compressor
124 Hz Full load
52 Hz Full load
Outdoor unit fan
Fan control
Fan control
Four-way valve (Y1S)
OFF
OFF
Main electronic expansion valve (EV1)
480 pls
240 pls
Subcooling electronic expansion valve
(EV3)
0 pls
0 pls
Hot gas bypass valve (SVP)
OFF
OFF
Ending conditions
2 sec.
2 sec.
Actuator
Pump down residual operation
Compressor
124 Hz Full load
Outdoor unit fan
STEP 7
Four-way valve (Y1S)
ON
Main electronic expansion valve (EV1)
0 pls
Subcooling electronic expansion valve
(EV3)
0 pls
Hot gas bypass valve (SVP)
OFF
Ending conditions
4 sec.
Summary of Contents for VRV III-S RXYMQ36 48PVJU
Page 1: ...RXYMQ36 48PVJU R 410A Heat Pump 60Hz SiUS34 907...
Page 9: ...SiUS34 907 Safety Considerations viii...
Page 237: ...Wiring Diagrams SiUS34 907 228 Appendix 2 2 Field Wiring RXYMQ36 48PVJU 3D065370...
Page 238: ...SiUS34 907 Wiring Diagrams Appendix 229 2 3 Indoor Unit FXFQ12M 18M 24M 30M 36MVJU 3D042620C...
Page 239: ...Wiring Diagrams SiUS34 907 230 Appendix FXZQ07M 09M 12M 18MVJU 3D059263...
Page 240: ...SiUS34 907 Wiring Diagrams Appendix 231 FXDQ07M 09M 12M 18M 24MVJU 3D050501A...
Page 241: ...Wiring Diagrams SiUS34 907 232 Appendix FXMQ07P 09P 12P 18P 24P 30P 36P 48PVJU 3D065984A...
Page 242: ...SiUS34 907 Wiring Diagrams Appendix 233 FXHQ12M 24M 36MVJU 3D048116A...
Page 243: ...Wiring Diagrams SiUS34 907 234 Appendix FXAQ07M 09M 12M 18M 24MVJU 3D046039D...
Page 244: ...SiUS34 907 Wiring Diagrams Appendix 235 FXLQ12M 18M 24MVJU FXNQ12M 18M 24MVJU 3D045644A...
Page 247: ...Option List SiUS34 907 238 Appendix...
Page 249: ...Example of Connection 240...
Page 263: ...Precautions for New Refrigerant R 410A SiUS34 907 254 Precautions for New Refrigerant R 410A...