Detailed Control Functions
SiBE341001
53
Function
2.7.2 Cooling Oil Return Operation
In order to prevent the compressor from running out of oil, the oil return operation is conducted to recover oil flown out
from the compressor to the system side.
[Start conditions]
Referring to the set conditions for the following items, start the oil return operation in cooling.
• 2 hours after initial power ON
• A lapse of every 1 ~ 2 hours during low-load operation
• A lapse of every 8 hours during high-load operation
*
In the case of multi-outdoor-unit system,
Master unit: Performs the operations listed in the table above.
Slave units: Operating units perform the operations listed in the table above.
Non-operating units perform the operations listed in the table above from the oil return operation.
(Non-operating unit stops during “oil return preparation operation”.)
<Indoor Unit>
<BS Unit>
Part Name
Electric
Symbol
Oil return operation
Compressor M1C
System frequency in oil return "IN" X 0.8, then constant control under
low pressure (
∗
When a unit has been stopped: 52Hz for all units)
Outdoor unit fan
M1F
Fan control in normal cooling
Electronic expansion valve (Main)
Y1E
480 pls
Electronic expansion valve (Refrigerant
charge)
Y2E
0 pls
Electronic expansion valve (Subcooling)
Y3E
0 pls
Solenoid valve (Refrigerant regulator
hot gas)
Y1S
OFF
Solenoid valve (Refrigerant regulator
liquid pipe)
Y2S
OFF
Solenoid valve (Refrigerant regulator
gas vent pipe)
Y3S
OFF
Solenoid valve (Hot gas)
Y4S
OFF
Solenoid valve (Circuit of oil return)
Y5S
OFF
Four way valve (Heat exchanger switch)
Y6S
OFF
Four way valve (Dual pressure gas pipe)
Y7S
OFF
Four way valve (Mixing unit)
Y8S
OFF
Solenoid valve (Mixing unit inlet)
Y9S
OFF
Ending condition
•
2 min. passed
OR
•
TsA-Te < 2°C
Part Name
Electric
Symbol
Cooling oil return operation
Thermostat ON unit
Thermostat OFF unit
Stopping unit
Indoor unit fan
M1F
Remote controller setting
Remote controller setting
OFF
Electronic expansion
valve (Main)
Y1E
Normal opening (SHS21)
Normal opening degree for
forced thermostat ON
224 pls
Part Name
Electric
Symbol
Cooling oil return operation
Electronic expansion
valve (EVSC)
Y1E
0 pls
Electronic expansion
valve (EVHS)
Y2E
0 ~ 60 pls (Pc_max ~ 2.85 MPa)
Electronic expansion
valve (EVLS)
Y3E
480 pls ( fully opened )
Electronic expansion
valve (EVH)
Y4E
0 pls
Electronic expansion
valve (EVL)
Y5E
760 pls ( fully opened )
Summary of Contents for RQYQ140-180PY1
Page 216: ...Piping Diagrams SiBE341001 207 Appendix 1 2 BS Unit BSVQ100 160 250PV1 4D057985B...
Page 217: ...SiBE341001 Piping Diagrams Appendix 208 BSV4Q100PV1 3D064148...
Page 218: ...Piping Diagrams SiBE341001 209 Appendix BSV6Q100PV1 3D064149...
Page 220: ...Wiring Diagrams for Reference SiBE341001 211 Appendix 2 2 BS Unit BSVQ100 160 250PV1 3D055928C...
Page 221: ...SiBE341001 Wiring Diagrams for Reference Appendix 212 BSV4Q100PV1 3D063928B...
Page 222: ...Wiring Diagrams for Reference SiBE341001 213 Appendix BSV6Q100PV1 3D063929B...
Page 223: ...SiBE341001 Option List Appendix 214 3 Option List 3 1 Option Lists Outdoor Unit 3D066354...