Oil Return Operation - Daikin VRV III RXYQ5-54PY1 Service Manual

Si34-601A
3.3

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.
3.3.1 Oil Return Operation in Cooling Operation
[Start conditions]
Referring to the set conditions for the following items, start the oil return operation in cooling.
• Cumulative oil feed rate
• Timer setting (Make this setting so as to start the oil return operation when the initial cumulative operating time
reaches two hours after power supply is turned ON and then every eight hours.)
Furthermore, the cumulative oil feed rate is computed from Tc, Te, and compressor loads.
Outdoor unit actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Accumulator oil return valve (SVO)
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 perform the operations listed in the table above from the oil return operation.
(Non-operating unit stops during "oil return preparation operation".)
* Actuators are based on RXYQ14~18P.
Fan
Electronic expansion valve
Function
Oil return preparation
operation
Take the current step as the
upper limit.
Fan control (Normal cooling) Fan control (Normal cooling) Fan control (Normal cooling)
OFF
480 pls
SH control
OFF
ON
20 sec.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit

Oil return operation

5 HP: 52 Hz
(→ Low pressure constant
control)
Other model:
52 Hz + ON + ON
(→ Low pressure
constant control)
↓
Maintain number of
compressors in oil
return preparation
operation ON
OFF
480 pls
0 pls
OFF
ON
• 3 min.
or
• Ts - Te<5°C
Cooling oil return operation
Remote controller setting
Remote controller setting
Normal opening
Normal opening with forced thermostat ON
Special Control
Post-oil-return operation
"
Same as the oil return
"
operation mode.
OFF
480 pls
0 pls
OFF
ON
• 3 min.
• Pe<0.6MPa
or
• HTdi>110°C
OFF
224 pls
111