Pump Down Residual Control - Daikin SkyAir RZR-TA Series Service Manual

SiUS281811EA
3.4

Pump Down Residual Control

If liquid refrigerant is retained in the evaporator when the compressor is activated, the liquid
refrigerant enters the compressor and dilutes oil therein resulting in a decrease of lubricity.
Therefore, pump down residual control is performed to collect the refrigerant retained in the
evaporator when the compressor stops.
3.4.1 Pump Down Residual Control in Cooling
Outdoor unit actuator
Compressor
Outdoor fan
Main electronic
expansion valve
Subcooling electronic
expansion valve
Four way valve
Hot gas bypass valve
Ending conditions
3.4.2 Pump Down Residual Control in Heating
Outdoor unit actuator
Compressor
Outdoor fan
Main electronic
expansion valve
Subcooling electronic
expansion valve
Four way valve
Hot gas bypass valve
Ending conditions
Part 4 Functions and Control
Electric Symbol
18/24 30/36/42/48
class class
M1C M1C
M1F M1F
M2F
Y1E Y1E
— Y3E
Y1S Y1S
Y2S —
Electric Symbol
18/24 30/36/42/48
class class
M1C M1C
M1F M1F
M2F
Y1E Y1E
— Y3E
Y1S Y1S
Y2S —

Pump down residual control:

Step 1
124 Hz
Fan control
480 pulse (Fully open)
0 pulse
OFF
OFF
2 seconds
Pump down residual control
124 Hz
STEP 7
0 pulse
0 pulse
ON
OFF
4 seconds
Special Control
Pump down residual control:
Step 2
Minimum frequency
Fan control
240 pulse (Half open)
0 pulse
OFF
OFF
2 seconds
115