Oil Return Operation - Daikin RMXS-L Series Service Manual

SiUS181631EA
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
Oil return operation in cooling operation is started referring to the following conditions:
The cumulative oil feed rate is computed from Tc, Te, and compressor loads.
Outdoor unit actuator
Compressor
Outdoor fan
Four way valve (Y1S)
Main electronic expansion valve (Y1E) 480 pulse
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass solenoid valve (Y2S)
Ending conditions
Indoor fan
Electronic expansion valve of
BP unit
Functions and Control
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 8 hours.)
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
SH control
OFF
20 sec.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return operation
52 Hz Full load (→ Low
pressure constant control)
OFF
480 pulse
0 pulse
OFF
• 3 min.
• Ts1 – Te < 5°C
or
(9°F)
Cooling oil return operation
Remote controller setting
Remote controller setting
Special Control
Post-oil-return operation
Same as in oil return
operation mode.
OFF
480 pulse
0 pulse
OFF
• 3 min.
• Pe < 0.6 MPa
(201 ftAq)
or
• HTdi > 110°C
(230°F)
OFF
SH control
77 pulse
SH control
57