Special Control
SiUS371901EB
149
Part 4 Functions and Control
7.2 Oil
Return
Operation
In order to prevent the compressor from running out of oil, the oil return operation is conducted to
recover oil that has flowed out from the compressor to the system side.
Tc : High pressure equivalent saturation temperature
Te : Low pressure equivalent saturation temperature
TsA: Suction pipe temperature detected by thermistor R3T
7.2.1 Oil Return Operation in Cooling Operation
Oil return operation is not conducted before 2 hours have elapsed from the activation of power
supply.
After 2 hours have elapsed, oil return operation starts when the following item meets the
reference value.
Total amount of oil discharged from the compressor
(The total amount of oil discharged from the compressor is computed from Tc, Te, and
compressor loads.)
Oil return control starts every 8 hours of cumulative operation of the compressor, even if the
reference value is not met.
Starting conditions
Part name
Electric symbol
Oil return operation
Compressor
M1C
Constant low pressure control
Inverter fan
M1F, M2F
For heat exchanger mode
Electronic expansion valve
(Heat exchanger upper)
Y1E
Same as normal control
Electronic expansion valve
(Heat exchanger lower)
Y3E
Electronic expansion valve
(Subcooling heat exchanger)
Y2E
0 pulse
Electric expansion valve (Subcooling
injection)
Y4E
760 pulse
Electronic expansion valve
(Refrigerant cooling)
Y5E
Same as normal control
Electronic expansion valve
(Receiver gas purge)
Y7E
0 pulse
Solenoid valve (Oil separator oil return)
Y1S
ON
Solenoid valve (Hot gas bypass)
Y2S
Same as normal control
Solenoid valve (Liquid shutoff)
Y3S
ON
Four way valve (HP/LP gas pipe)
Y4S
Hold
Four way valve (Heat exchanger lower)
Y5S
Hold
Four way valve (Heat exchanger upper)
Y6S
Hold
Solenoid valve (Accumulator oil return)
Y7S
Same as normal control
Ending condition
•
A lapse of 3 minutes
•
TsA – Te < 3
°
C (5.4°F)
•
A lapse of 12 minutes while the frequency is
more than that of oil return operation.
&
OR
Summary of Contents for REYQ72-432XAYCU
Page 455: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 448 REYQ144 168XATJU REYQ144 168XATJA 2D119206B ...
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Page 461: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 454 FXZQ05 07 09 12 15 18TAVJU 3D110443A ...
Page 463: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 456 FXEQ07 09 12 15 18 24PVJU 3D098557A ...
Page 464: ...Wiring Diagrams SiUS371901EB 457 Part 7 Appendix FXDQ07 09 12 18 24MVJU C 3D050501C ...
Page 468: ...Wiring Diagrams SiUS371901EB 461 Part 7 Appendix FXHQ12 24 36MVJU 3D048116C ...
Page 469: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 462 FXAQ07 09 12 18 24PVJU 3D075354F ...
Page 475: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 468 VAM1200GVJU 3D073270D ...
Page 478: ...Wiring Diagrams SiUS371901EB 471 Part 7 Appendix BS6 8Q54TVJ 2D089122B ...
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