Daikin VRV II REYQ10MY1B, Service Manual

Page: 86 / 309

Si39-306 Special Control
Function 75
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
* Actuators are based on REYQ16M.
3.5.2 Pump-down Residual Operation in Heating Operation
* Actuators are based on REYQ16M.
Actuator Master unit operation Slave unit operation
Compressor 210 Hz + OFF + OFF OFF
Outdoor unit fan Fan control OFF
Four way valve 1 OFF OFF
Four way valve 2 OFF OFF
Main motorized valve (EV1) 1400 pls 0 pls
Sub motorized valve (EV2) 1400 pls 0 pls
Sub-cooling motorized valve (EV3) 0 pls 0 pls
Hot gas bypass valve (SVP) ON OFF
Oil equalization valve (SVO) ON OFF
Receiver gas charging valve (SVL) OFF OFF
Receiver gas discharge valve (SVG) OFF OFF
Discharge pipe stop valve (SVR) OFF OFF
Non-operating unit liquid pipe stop
valve (SVSL)
OFF ON
High pressure gas pipe pressure
reduction valve (SVC)
OFF OFF
Ending conditions
•
5 min.
•
Pe<0.5 MPa
•
Td>110
°
C
Indoor unit EV opening 0 pls
or
Actuator Master unit operation Slave unit operation
Compressor 124 Hz + OFF + OFF OFF
Outdoor unit fan STEP8 STEP5
Four way valve 1 Holds ON Holds ON
Four way valve 2 Holds ON Holds ON
Main motorized valve (EV1)
Four way valve 1
OFF:1400 pls
ON:0 pls Four way valve 1
OFF:1400 pls
ON: 0 pls
Sub motorized valve (EV2)
Four way valve 2
OFF:1400 pls
ON:0 pls Four way valve 2
OFF:1400 pls
ON: 0 pls
Sub-cooling motorized valve (EV3) 0 pls 0 pls
Hot gas bypass valve (SVP) ON OFF
Oil equalization valve (SVO) ON OFF
Receiver gas charging valve (SVL) OFF OFF
Receiver gas discharge valve (SVG) OFF OFF
Discharge pipe stop valve (SVR) ON ON
Non-operating unit liquid pipe stop
valve (SVSL)
ON ON
High pressure gas pipe pressure
reduction valve (SVC)
OFF OFF
Ending conditions
•
30 sec.
•
Pe<0.25 MPa
•
Td>110
°
C
Indoor unit EV opening Fully open
or