Daikin VRV III-S RXYMQ36 48PVJU Service Manual page 47

Special Control
3.2.2 Oil Return Operation in Heating Operation
[Conditions to start]
The heating oil-returning operation is started referring following conditions.
 Integrated amount of displaced oil
 Timer
(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.
Outdoor Unit Actuator
Compressor
Outdoor unit fan
Four-way valve (Y1S)
Main electronic expansion valve (EV1) SH control
Subcooling electronic expansion valve
(EV3)
Hot gas bypass valve (SVP)
Ending conditions
* From the preparing oil-returning operation to the oil-returning operation, and from the oil-returning operation to
the operation after oil-returning, the compressor stops for 1 minute to reduce noise on changing of the four-way
valve.
Fan
Electronic expansion valve
38
Oil return preparation
operation
Upper limit control
STEP 8
ON
0 pls
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 pls
0 pls
OFF
• 12 min.
• Ts1 - Te<41°F
or
{
&
• Tb>52°F
Heating oil return operation
SiUS34-907
Post-oil-return operation
2-step increase from
36 Hz Unload to
(Pc - Pe>58 psi)
every 20 sec.
STEP 8
ON
55 pls
0 pls
OFF
• 160 sec.
or
• Pc - Pe>58 psi
OFF
OFF
OFF
416 pls
256 pls
416 pls
Function