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

Special Control
3.2

Oil Return Operation

Oil flown from the compressor to the side of system is collected by oil-returning 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-returning operation is started referring following conditions.
 Integrated amount of displaced oil
 Timer
Outdoor unit actuator
Compressor
Outdoor unit fan
Four-way valve
Main electronic expansion valve
(EV1)
Hot gas bypass valve (SVP)
Receiver gas discharging valve
(SVG)
Ending conditions
Fan
Electronic expansion valve
18
(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.
Oil return preparation
operation
Upper limit control
Fan control
OFF
1400 pls
OFF
OFF
20 seconds
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit

Oil return operation

124 Hz
Fan control
OFF
1400 pls
ON
OFF
 6 minutes
OR
 Ts – Te < 9°F
Cooling oil return operation
Set air volume
Normal opening
SiUS28-902_B
Post-oil-return operation
124 Hz
Fan control
OFF
1400 pls
ON
OFF
3 minutes
OFF
OFF
200 pls
200 pls
Function