Oil Return Operation - Daikin VRV II REYQ8MY1B Service Manual

Si39-306
3.2

Oil Return Operation

In order to prevent the running-out of refrigerating machine oil in the compressor, the oil flowing
out from the compressor to the system side is collected through the oil return operation.
3.2.1 Oil Return Operation in Cooling Operation
[Starting conditions]
Start oil return operation in cooling operation referring to the following conditions.
* Cumulative oil return amount
* Timer
Cumulative compressor operating time after power supply turns on exceeds 2 hours and the
time after the completion of previous oil return operation exceeds 8 hours.
Furthermore, the cumulative oil return is calculated according to To, Te, and compressor load.
Actuator
Compressor
Outdoor unit fan
Four way valve 1
Four way valve 2
Main motorized valve (EV1)
Sub motorized valve (EV2)
Sub-cooling motorized valve (EV3)
Hot gas bypass valve (SVP)
Oil equalization valve (SVO)
Receiver gas charging valve (SVL)
Receiver gas discharge valve (SVG) OFF
Discharge pipe stop valve (SVR)
Non-operating unit liquid pipe stop
valve (SVSL)
High pressure gas pipe pressure
reduction valve (SVC)
Ending conditions
* 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 performs the operations listed in the table above from the oil return operation.
* Actuators are based on REYQ16M.
Fan
Electronic expansion valve
Function
Oil return preparation
operation
Upper limit control
Fan control
OFF
OFF
1400 pls
1400 pls
SH control
OFF
ON
OFF
OFF
OFF
ON
1 min.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit

Oil return operation

124 Hz + ON + OFF
Fan control
OFF
OFF
1400 pls
1400 pls
0 pls
ON
ON
OFF
OFF
OFF
OFF
ON
• 6 min.
or
• Ts - Te<5
Cooling oil return operation
Set Air Volume
Normal opening
Special Control
Post-oil-return operation
52 Hz + OFF + OFF
Fan control
OFF
OFF
1400 pls
1400 pls
0 pls
ON
ON
OFF
OFF
OFF
OFF
ON
30 sec.
OFF
OFF
200 pls
200 pls
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