Daikin RQYQ140-180PY1 Service Manual page 62

Detailed Control Functions
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
Part Name
Compressor
Outdoor unit fan
Electronic expansion valve (Main)
Electronic expansion valve (Refrigerant
charge)
Electronic expansion valve (Subcooling)
Solenoid valve (Refrigerant regulator
hot gas)
Solenoid valve (Refrigerant regulator
liquid pipe)
Solenoid valve (Refrigerant regulator
gas vent pipe)
Solenoid valve (Hot gas)
Solenoid valve (Circuit of oil return)
Four way valve (Heat exchanger switch)
Four way valve (Dual pressure gas pipe)
Four way valve (Mixing unit)
Solenoid valve (Mixing unit inlet)
Ending condition
* 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>
Part Name
Indoor unit fan
Electronic expansion
valve (Main)
<BS Unit>
Part Name
Electronic expansion
valve (EVSC)
Electronic expansion
valve (EVHS)
Electronic expansion
valve (EVLS)
Electronic expansion
valve (EVH)
Electronic expansion
valve (EVL)
53
Electric
Symbol
M1C
M1F
Y1E
Y2E
Y3E
Y1S
Y2S
Y3S
Y4S
Y5S
Y6S
Y7S
Y8S
Y9S
Electric
Symbol
Thermostat ON unit
M1F Remote controller setting
Y1E Normal opening (SHS21)
Electric
Symbol
Y1E
Y2E
Y3E
Y4E
Y5E
Oil return operation
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)
Fan control in normal cooling
OR
Cooling oil return operation
Thermostat OFF unit
Remote controller setting
Normal opening degree for
forced thermostat ON
Cooling oil return operation
0 pls
0 ~ 60 pls (Pc_max ~ 2.85 MPa)
480 pls ( fully opened )
0 pls
760 pls ( fully opened )
480 pls
0 pls
0 pls
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
• 2 min. passed
• TsA-Te < 2°C
Stopping unit
OFF
224 pls
SiBE341001
Function