Special Control
Si18-525B
116
Function
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
124 Hz
2-step increase from
52 Hz to
(Pc - Pe>0.4 MPa) time
Outdoor unit fan
STEP8
High pressure control
STEP8
Four way valve
ON
OFF
ON
Main electronic expansion valve
(EV1)
SH control
2000 pls
200~400 pls
Subcooling electronic expansion
valve (EV2)
0 pls
0 pls
0 pls
Hot gas bypass valve (SVP)
OFF
ON
ON
Receiver gas discharging valve
(SVG)
ON
→
OFF
ON
→
OFF
ON
→
OFF
Ending conditions
130 sec.
•
Max. 735 sec.
•
Ts - Te<5
•
160 sec.
•
Pc - Pe>0.4MPa
or
or
Indoor actuator
Heating oil return operation
Indoor unit fan
Thermostat ON unit
OFF
Stopping unit
OFF
Thermostat OFF unit
OFF
BP unit electronic expansion
valve
Thermostat ON unit
SH control
Stopping unit
80 pls
Thermostat OFF unit
SH control
Summary of Contents for D-Series
Page 1: ...Si18 525B Applied Models Super Multi Plus Cooling only Super Multi Plus Heat Pump D Series ...
Page 33: ...List of Functions Si18 525B 20 List of Functions ...
Page 71: ...Specifications Si18 525B 58 Specifications ...
Page 117: ...Refrigerant Flow for Each Operation Mode Si18 525B 104 Refrigerant Circuit ...
Page 171: ...Indoor Unit SkyAir Models Si18 525B 158 Function ...
Page 207: ...Test Operation and Field Setting for RA Indoor Unit Si18 525B 194 Test Operation ...
Page 336: ...Si18 525B Service Check Function Troubleshooting 323 ...
Page 469: ...Wiring Diagrams Si18 525B 456 Appendix ...
Page 475: ...Si18 525B vi Index ...
