Daikin RMXS-L Series Service Manual page 56

Special Control
3.2.2 Oil Return Operation in Heating Operation
<Conditions to start>
Oil return operation in heating operation is started referring to the following conditions:
 Integrated amount of displaced oil
 Timer setting (Make this setting so as to start the oil return operation when the initial cumulative
The integrated amount of displaced oil is derived from Tc, Te, and the compressor load.
Outdoor unit actuator
Compressor
Outdoor fan
Four way valve (Y1S)
Main electronic expansion valve (Y1E) SH control
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass solenoid valve (Y2S)
Ending conditions
From the preparation to the oil return operation, and from the oil return operation to the post-oil-
return operation, the compressor stops for 1 minute to reduce noise on changing of the four way
valve.
Indoor fan
Electronic expansion valve of
BP unit
47
operating time reaches 2 hours after power supply is turned ON and then every 8 hours.)
Oil return preparation
operation
Upper limit control
STEP 8
ON
0 pulse
OFF
2 min.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return operation
140 Hz Full load
OFF
OFF
480 pulse
0 pulse
OFF
 12 min.
 Ts1 – Te < 5°C
or
(9°F)
&
 Tb > 11°C
(51.8°F)
Heating oil return operation
SiUS181305E
Post-oil-return operation
36 Hz Unload
+2 steps / 20 sec.
(until Pc - Pe > 0.4 MPa)
(134 ftAq)
STEP 8
ON
55 pulse
0 pulse
OFF
 160 sec.
 Pc – Pe > 0.4 MPa
or
(134 ftAq)
OFF
OFF
OFF
SH control
80 pulse
SH control
Function