Specifications

Special Control SiUS39-602
54 Function
3.5 Pump-down Residual Operation
If any liquid refrigerant remains in the heat exchanger during compressor startup, the liquid
refrigerant will enter the compressor, resulting in the dilution of the refrigerating machine oil in
the compressor and the degradation of lubricating capacity.
Therefore, before the compressor stops, pump-down operation is performed to collect the
refrigerant in the heat exchanger.
3.5.1 Pump-down Residual Operation in Cooling Operation
Actuator Operation
Compressor 210 Hz + OFF
Outdoor unit fan Fan control
Four way valve 1 OFF
Four way valve 2 OFF
Main motorized valve (EV1) 1400 pls
Sub motorized valve (EV2) 1400 pls
Sub-cooling motorized valve (EV3) 0 pls
Hot gas bypass valve (SVP) ON
Oil equalization valve (SVO) ON
Receiver gas charging valve (SVL) OFF
Receiver gas discharge valve (SVG) OFF
Discharge pipe stop valve (SVR) OFF
Non-operating unit liquid pipe stop valve (SVSL) OFF
High pressure gas pipe pressure reduction
valve (SVC)
OFF
Ending conditions
• 5 min.
• Pe < 72.5 psi
• Td > 230°F
Indoor unit EV opening 0 pls
or