Pump-Down Residual Operation - Daikin Super Multi Plus E-Series FTXG25EV1BW Service Manual

Special Control
3.4

Pump-down Residual Operation

When activating compressor, if the liquid refrigerant remains in the heat exchanger, the liquid
enters into the compressor and dilutes oil therein resulting in decrease of lubricity.
Therefore, the pump-down residual operation is performed to collect the refrigerant in the heat
exchanger when the compressor is down.
3.4.1 Pump-down Residual Operation in Cooling Operation
Actuator
Compressor
Outdoor fan
Four way valve (Y1S)
Main electronic expansion valve (Y1E)
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass valve (Y2S)
Ending conditions
3.4.2 Pump-down Residual Operation in Heating Operation
Actuator
Compressor
Outdoor fan
Four way valve (Y1S)
Main electronic expansion valve (Y1E)
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass valve (Y2S)
Ending conditions
86

Pump-down residual operation

Step 1
124 Hz Full load
Fan control
OFF
480 pls
0 pls
OFF
2 sec.
Pump-down residual operation
124 Hz Full load
STEP 7
ON
0 pls
0 pls
OFF
4 sec.
SiBE18-821_C
Step 2
52 Hz Full load
Fan control
OFF
240 pls
0 pls
OFF
2 sec.
Function