Daikin VRV II RXYQ5MATL, Service Manual

Page: 92 / 331

Si39-504 Special Control
Function 81
3.4 Pump-down Residual Operation
3.4.1 Pump-down Residual Operation in Cooling Operation
If the liquid refrigerant stays in the heat exchanger at the startup of a compressor, this liquid refrigerant enters the
compressor, thus resulting in diluted oil in the compressor and then degraded lubrication performance.
Consequently, in order to recover the refrigerant in the heat exchanger while the compressor stops, the pump-down
residual operation is conducted.
*
Actuators are based on RXYQ16MA.
3.4.2 Pump-down Residual Operation in Heating Operation
* Actuators are based on RXYQ16MA.
Actuator Master unit operation Slave unit operation
Compressor 210 Hz + OFF + OFF OFF
Outdoor unit fan Fan control OFF
Four way valve OFF OFF
Main motorized valve (EV1) 2000 pls 0 pls
Subcooling motorized valve (EV2) 0 pls 0 pls
Hot gas bypass valve (SVP) OFF ON
Receiver gas discharging valve (SVG) OFF OFF
Non-operating unit liquid pipe stop
valve (SVSL)
ON ON
Ending conditions
•
5 min.
•
Pe<0.49 MPa
•
Td>110
°
C
or
Actuator Master unit operation Slave unit operation
Compressor 124 Hz + OFF + OFF OFF
Outdoor unit fan STEP7 STEP4
Four way valve ON ON
Main motorized valve (EV1) 0 pls 0 pls
Subcooling motorized valve (EV2) 0 pls 0 pls
Hot gas bypass valve (SVP) ON OFF
Receiver gas discharging valve (SVG) OFF OFF
Non-operating unit liquid pipe stop
valve (SVSL)
ON ON
Ending conditions
•
30 sec.
•
Pe<0.25 MPa
•
Td>110
°
C
or