Special Control SiBE31-801_C105 Function8. Special Control8.1 Pump down Residual OperationIf the liquid refrigerant stays in the Evaporator at the startup of a compressor, this liquid refrigerant enters thecompressor, thus resulting in diluted oil in the compressor and then degraded lubrication performance.Consequently, in order to recover the refrigerant in the Evaporator while the compressor stops, the pump down residualoperation is conducted.8.1.1 Pump down Residual Operation in Cooling Operation (Outdoor Unit)Actuator Elect.symbolSTEP 1 STEP 2Master unitoperationSlave unitoperation(RTSYQ20PY1only)Master unitoperationSlave unitoperation(RTSYQ20PY1only)Compressor 1 M1C 124 HzOFF52 HzOFFCompressor 2 M2C OFF OFFCompressor 3 M3C OFF OFFOutdoor unit fan 1 M1F Fan control OFF Fan control OFFOutdoor unit fan 2 M2FElectronic expansion valve (Main) Y1E 480 pls 0 pls 240 pls 0 plsElectronic expansion valve(Subcooling) Y3E 0 pls 0 pls 0 pls 0 plsElectronic expansion valve(Refrigerant charge) Y2E 80 pls 80 pls 80 pls 80 plsSolenoid valve (Refrigerantregulator gas purging pipe) Y1S OFF OFF OFF OFFFour way valve (Heat exchangerswitch) Y3S OFF OFF OFF OFFSolenoid valve (Refrigerantregulator liquid pipe ) Y4S OFF OFF OFF OFFSolenoid valve (Hot gas) Y5S OFF OFF OFF OFFSolenoid valve (Main bypass) Y6S ON ON ON ONSolenoid valve (Refrigerantregulator discharge pipe) Y7S OFF OFF OFF OFFSolenoid valve (Refrigerantregulator discharge pipe) Y8S OFF OFF OFF OFFFour way valve (High/low pressuregas pipe switch) Y2S ON ON ON ONEnding conditions• 5 min.• Master unit Pe<0.49 MPa• Master unit Pc>2.94 MPa• Master unit Tdi>110°C• Master unit Tp>125°C• 45 sec.• Master unit Pe<0.24 MPa• Master unit Tp>160°C• Master unit Pc>3.14 MPaor or
