SiBE18-821_C
Special Control
Function
83
3.2
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.
3.2.1 Oil Return Operation in Cooling Operation
[Conditions to start]
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 2 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
Oil return preparation
operation
Oil return operation
Post-oil-return operation
Compressor
Take the current step as the
upper limit.
52 Hz Full load (
→
Low
pressure constant control)
Same as the
“
oil return
operation
”
mode.
Outdoor fan
Fan control (Normal cooling) Fan control (Normal cooling) Fan control (Normal cooling)
Four way valve (Y1S)
OFF
OFF
OFF
Main electronic expansion valve
(Y1E)
480 pls
480 pls
480 pls
Subcooling electronic expansion
valve (Y3E)
SH control
0 pls
0 pls
Hot gas bypass valve (Y2S)
OFF
OFF
OFF
Ending conditions
20 sec.
•
3 min.
•
Ts – Te < 5
°
C
•
3 min.
•
Pe < 0.6 MPa
•
HTdi > 110
°
C
or
or
Indoor unit actuator
Cooling oil return operation
Indoor fan
Thermostat ON unit
Remote controller setting
Stopping unit
OFF
Thermostat OFF unit
Remote controller setting
Electronic expansion valve of
BP unit
Thermostat ON unit
SH control
Stopping unit
77 pls
Thermostat OFF unit
SH control
