Daikin VRVIII-S Service Manual page 58

SiENBE34-703
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
Outdoor Unit Actuator
Compressor
Outdoor unit fan
Four way valve
Main electronic expansion valve
(EV1)
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
Function
(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
STEP8
ON
SH control
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.
or
• Ts1 - Te<5°C
{
&
• Tb>11°C
Heating oil return operation
Special Control
Post-oil-return operation
2-step increase from
36 Hz Unload to
(Pc - Pe>0.4 MPa)
every 20 sec.
STEP8
ON
55 pls
0 pls
OFF
• 160 sec.
or
• Pc - Pe>0.4MPa
OFF
OFF
OFF
416 pls
256 pls
416 pls
47