SiUS372201EA
Special Control
Part 4 Functions and Control
146
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 R5T
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
Function of functional part
Compressor motor
M1C, M2C
Constant low pressure control
Fan motor
M1F, M2F
For heat exchanger mode
Electronic expansion valve (Heat exchanger right upper)
Y1E
Same as normal control
Electronic expansion valve (Heat exchanger right lower)
Y2E
Electronic expansion valve (Heat exchanger left)
Y5E
Electronic expansion valve (Subcooling heat exchanger)
Y3E
0 pulse
Electronic expansion valve (Receiver gas purge)
Y4E
0 pulse
Electronic expansion valve (Refrigerant cooling IPM)
Y6E
Same as normal control
Electronic expansion valve (Refrigerant cooling air)
Y7E
Solenoid valve (Oil separator oil return)
Y1S, Y2S
ON
Solenoid valve (Liquid shutoff)
Y3S
ON
Solenoid valve (Accumulator oil return)
Y4S
ON
Solenoid valve (Refrigerant adjustment)
Y5S
OFF
Solenoid valve (Injection)
Y6S
ON
Four way valve (Heat exchanger right upper)
Y10S
Hold
Four way valve (Heat exchanger right lower)
Y7S
Four way valve (Heat exchanger left)
Y9S
Four way valve (HP/LP gas pipe)
Y8S
Solenoid valve (Refrigerant cooling bypass)
Y11S
Same as normal control
Ending condition
A lapse of 3 minutes
TsA – Te < 3
C (5.4°F)
A lapse of 6 minutes while the frequency is
more than that of oil return operation.
&
OR
Summary of Contents for REYQ-AATJA
Page 1: ...Service Manual Heat Recovery 60 Hz REYQ AATJA 208 230 V REYQ AAYDA 460 V SiUS372201EA...
Page 465: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 458 BS6 8Q54TVJ 2D089122B...
Page 466: ...Wiring Diagrams SiUS372201EA 459 Part 7 Appendix BS10 12Q54TVJ 2D089121B...
Page 469: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 462 BSF6 8Q54TVJ 2D123905A...
Page 472: ...Wiring Diagrams SiUS372201EA 465 Part 7 Appendix FXZQ05 07 09 12 15 18TAVJU 3D110443A...
Page 476: ...Wiring Diagrams SiUS372201EA 469 Part 7 Appendix FXEQ07 09 12 15 18 24PVJU 3D098557A...
Page 477: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 470 FXDQ07 09 12 18 24MVJU C 3D050501C...
Page 483: ...SiUS372201EA Wiring Diagrams Part 7 Appendix 476 FXHQ12 24 36MVJU 3D048116C...
Page 484: ...Wiring Diagrams SiUS372201EA 477 Part 7 Appendix FXAQ07 09 12 18 24PVJU 3D075354F...
Page 490: ...Wiring Diagrams SiUS372201EA 483 Part 7 Appendix VAM1200GVJU 3D073270D...