Pump-Down Residual Operation - Daikin CMSQ200A7W1B Service Manual

SiBE28-805
3.4

Pump-down Residual Operation

3.4.1 Pump-down Residual Operation in Cooling Operation
If the liquid refrigerant stays in the Evaporator 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 Evaporator while the compressor stops, the pump-down residual
operation is conducted.
Actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Accumulator oil return valve (SVO)
Ending conditions
3.4.2 Pump-down Residual Operation in Heating Operation
Actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Accumulator oil return valve (SVO)
Ending conditions
Function
Master unit operation
124 Hz
Fan control
OFF
480 pls
0 pls
OFF
ON
• 5 min.
or
Master unit operation
124 Hz
STEP7
ON
0 pls
0 pls
OFF
ON
• 3 min.
or
Special Control
Slave unit operation
OFF
OFF
OFF
0 pls
0 pls
OFF
ON
Slave unit operation
OFF
STEP4
ON
0 pls
0 pls
OFF
ON
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