Panasonic U-4..6ML5XPQ, Service Manual

Page: 67 / 283

Special Control
Function 55
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.
* 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.
Outdoor Unit Actuator
Oil return preparation
operation
Oil return operation Post-oil-return operation
Compressor Upper limit control 140 Hz Full load
2-step increase from
36 Hz Unload to
(Pc - Pe>0.4 MPa)
every 20 sec.
Outdoor unit fan STEP8 OFF STEP8
Four way valve ON OFF ON
Main electronic expansion valve
(EV1)
SH control 480 pls 55 pls
Subcooling electronic expansion
valve (EV3)
0 pls 0 pls 0 pls
Hot gas bypass valve (SVP) OFF OFF OFF
Ending conditions 2 min.
•
12 min.
•
Ts1 - Te<5°C
•
Tb>11°C
•
160 sec.
•
Pc - Pe>0.4MPa
or
&
{
or
Indoor unit actuator Heating oil return operation
Fan
Thermostat ON unit OFF
Stopping unit OFF
Thermostat OFF unit OFF
Electronic expansion valve
Thermostat ON unit 416 pls
Stopping unit 256 pls
Thermostat OFF unit 416 pls
Panasonic