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SiUS281811EA
Special Control
Part 4 Functions and Control
115
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
3.4.2 Pump Down Residual Control in Heating
Outdoor unit actuator
Electric Symbol
Pump down residual control:
Step 1
Pump down residual control:
Step 2
18/24
class
30/36/42/48
class
Compressor
M1C
M1C
124 Hz
Minimum frequency
Outdoor fan
M1F
M1F
M2F
Fan control
Fan control
Main electronic
expansion valve
Y1E
Y1E
480 pulse (Fully open)
240 pulse (Half open)
Subcooling electronic
expansion valve
—
Y3E
0 pulse
0 pulse
Four way valve
Y1S
Y1S
OFF
OFF
Hot gas bypass valve
Y2S
—
OFF
OFF
Ending conditions
2 seconds
2 seconds
Outdoor unit actuator
Electric Symbol
Pump down residual control
18/24
class
30/36/42/48
class
Compressor
M1C
M1C
124 Hz
Outdoor fan
M1F
M1F
M2F
STEP 7
Main electronic
expansion valve
Y1E
Y1E
0 pulse
Subcooling electronic
expansion valve
—
Y3E
0 pulse
Four way valve
Y1S
Y1S
ON
Hot gas bypass valve
Y2S
—
OFF
Ending conditions
4 seconds
Summary of Contents for SkyAir RZR-TA Series
Page 1: ...Service Manual Cooling Only 60 Hz Heat Pump 60 Hz RZR TA RZQ TA Series SiUS281811EA...
Page 202: ...SiUS281811EA 196 Part 6 Service Diagnosis 5 15 Fan Motor Connector Check for FTQ TA 311...
Page 323: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 317 RZR18 24TAVJUA RZQ18 24TAVJUA 3D124495...
Page 327: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 321 FHQ18 24 30PVJU FHQ36 42MVJU 3D048116C...
Page 328: ...Wiring Diagrams SiUS281811EA 322 Part 7 Appendix FAQ18 24TAVJU 3D114844B...
Page 329: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 323 FBQ18 24 30 36 42 48PVJU 3D065984J...