Oil Return Operation - Daikin FCQ18PVJU Service Manual

SiUS28-902_a
3.2

Oil Return Operation

Oil discharged by the compressor to the field piping is collected by the oil return operation.
3.2.1 Oil Return Operation in Cooling Operation
[Conditions to start]
The cooling oil-returning operation is started under the following conditions:
 Integrated amount of displaced oil
 Timer
Outdoor unit actuator
Compressor
Outdoor unit fan
Four-way valve
Main electronic expansion valve
(EV1)
Subcooling electronic expansion
valve (EV2)
Hot gas bypass valve (SVP)
Receiver gas discharging valve
(SVG)
Ending conditions
Fan
Electronic expansion valve
Function
After the power is turned on, integrated operatingtime is 2 hours and subsequently every 8
hours.)
In addition, the 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
SH control
OFF
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
124 Hz
Fan control
OFF
1400 pls
0 pls
ON
OFF
• 6 min.
or
• Ts - Te<5
Cooling oil return operation
Set Air Volume
Normal opening
Special Control
Postoil-return operation
124 Hz
Fan control
OFF
1400 pls
0 pls
ON
OFF
3 min.
OFF
OFF
200 pls
200 pls
22