Pump Down Residual Operation - Daikin RXSQ24TAVJU Service Manual

SiUS331708EA
3.4

Pump Down Residual Operation

When activating the compressor, if liquid refrigerant remains in the evaporator, the liquid enters the compressor
and dilutes oil therein resulting in a decrease in lubricity.
Therefore, pump down residual operation is performed to collect refrigerant in the evaporator when the
compressor is stopped.
3.4.1 Pump Down Residual Operation in Cooling
Outdoor unit actuator
Compressor
Outdoor fan
Four way valve
Main electronic expansion
valve
Subcooling electronic
expansion valve
Hot gas bypass valve
Injection valve
Ending conditions
3.4.2 Pump Down Residual Operation in Heating
Outdoor unit actuator
Compressor
Outdoor fan
Four way valve
Main electronic expansion
valve
Subcooling electronic
expansion valve
Hot gas bypass valve
Injection valve
Ending conditions
Functions and Control
Electric symbol
24/36 class 48 class 60 class
STEP 18 load (24/36 class)
M1C M1C M1C
58 rps (48/60 class)
M1F,
M1F M1F Fan control
M2F
Y1S Y1S Y1S OFF
Y1E Y1E Y1E 480 pulse (Fully open)
 
Y3E 0 pulse
 
Y2S OFF

Y3S Y3S OFF
2 seconds
Electric symbol
24/36 class 48 class 60 class
STEP 18 load (24/36 class)
M1C M1C M1C
STEP 9 load (48/60 class)
M1F,
M1F M1F STEP 7
M2F
Y1S Y1S Y1S ON
Y1E Y1E Y1E 0 pulse
 
Y3E 0 pulse
 
Y2S OFF

Y3S Y3S OFF
4 seconds (24/36 class)
Up to 3 minutes (48/60 class)
Pump down residual operation:
Step 1
Pump down residual operation
Special Control
Pump down residual operation:
Step 2
STEP 6 load (24/36 class)
24 rps (48/60 class)
Fan control
OFF
240 pulse (Half open) (24/36 class)
480 pulse (Fully open) (48/60 class)
0 pulse
OFF
OFF
2 seconds
50