Oil Return Operation - Daikin SkyAir RZR-P Series Service Manual

SiUS281117
3.2

Oil Return Operation

Oil flown from the compressor to the side of system is collected by oil return operation, in case
of that oil in the compressor runs down.
3.2.1 Oil Return Operation in Cooling
Tc: High pressure equivalent saturation temperature
Te: Low pressure equivalent saturation temperature
Ts: Suction pipe temperature detected by thermistor
[Conditions to start]
The cooling oil return operation is started referring following conditions.
 Integrated amount of displaced oil
 Timer
Parts Name Symbol
Compressor

(INV.)
Outdoor unit fan 
Four-way valve 20S1
Electronic
expansion valve EV1
(Main)
Solenoid valve
SVP
(Hot gas)
Solenoid valve
(Receiver gas SVG
discharging)
Ending conditions
Fan
Electronic expansion valve
38
(After the power is turned ON, integrated operating-time is 2 hours and subsequently every 8
hours.)
In addition, integrated amount of displaced oil is derived from Tc, Te, and the compressor
load.
Electric Symbol
RZR18/24/32P RZR36/42P
RZQ18/24/30P RZQ36/42P
M1C M1C
M1F
M1F
M2F
Y1S Y1S
Y1E Y1E
Y2S Y2S

Y3S
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return
preparation

Oil return operation

operation
Upper limit
124 Hz
control
Fan control Fan control
OFF OFF
1400 pls 1400 pls
OFF ON
OFF OFF
 6 minutes
20 seconds OR
 Ts – Te < 9°F
Cooling oil return operation
Special Control
Post-oil-return
operation
124 Hz
Fan control
OFF
1400 pls
ON
OFF
3 minutes
Set air volume
OFF
OFF
Normal opening
200 pls
200 pls
Function and Control