Special Control
SiUS34-801A_b
54
VRVIII R-410A Heat Pump 60Hz
7.3.2 Heating Oil Return Operation
[Start conditions]
Referring to the following conditions, start heating oil return operation.
• Integral oil rise rate is reached to specified level.
• When cumulative compressor operating time exceeds 8 hours (2 hours when the power supply turns ON for the
first time)
Furthermore, the integral oil rise rate is calculated by Tc, Te, and compressor loads.
The higher the compressor operating step No., the cumulative refrigerant oil consumption increases.
When high pressure reaches the high level (i.e., Pc > 27k), the system will switch to defrost operation (refer to Section 7.4
for detail).
Cooling indoor unit actuator
Oil return operation
Fan
Thermo ON unit
Remote controller setting
Unit not in operation
OFF
Thermo OFF unit
Remote controller setting
Motorized valve
Thermo ON unit
Normal opening degree
Unit not in operation
192pls
Thermo OFF unit
Normal opening degree for forced thermostat ON
Actuator
Symbol
Elect. symbol
Oil return operation
RXYQ
144PTJU
For any model
other than that
shown on the left
Compressor 1
—
M1C
M1C
Maintain load that was applied before oil return operation.
When current circulation rate < circulation rate required
for oil return operation, turn ON the STD compressor
every 10 seconds (up to 3 units at maximum).
Compressor 2
M2C
M2C
Outdoor unit fan 1
—
M1F
M1F
When outdoor unit heat exchanger is condenser, the
fan will run under cooling fan control.
When outdoor unit heat exchanger is evaporator, the
fan will run at the fan step 7 or 8.
Outdoor unit fan 2
M2F
—
Electronic expansion
valve (main)
EVM
Y1E
Y1E
20SA=ON : PI control
20SA=OFF : 418pls
Y3E
Electronic expansion
valve (subcooling)
EVT
Y2E
Y3E
PI control
Y5E
Electronic expansion
valve (refilling refrigerant)
EVJ
Y4E
Y2E
80pls
Four
-way
valve (for heat
exchanger selection)
20SA
Y2S
Y3S
When outdoor unit heat exchanger is condenser, the
valve will turn OFF.
When outdoor unit heat exchanger is evaporator, the
valve will turn ON.
Y9S
Four
-way
valve (for high-
and low-pressure gas
pipe selection)
20SB
Y8S
Y2S
OFF
Solenoid valve (main
bypass)
SVE
Y5S
Y6S
OFF
Y10S
Solenoid valve (hot gas)
SVP
Y4S
Y5S
0pls
Solenoid valve (liquid
pipe of refrigerant
regulator)
SVL
Y3S
Y4S
0pls
Solenoid valve (gas
discharge pipe of
refrigerant regulator)
SVG
Y1S
Y1S
0pls
Solenoid valve (drain pipe
of refrigerant regulator)
SVO
Y7S
Y7S
0pls
Solenoid valve (discharge
pipe of refrigerant
regulator)
SVT
Y6S
Y8S
0pls
OR
Summary of Contents for VRV III
Page 15: ...SiUS34 801A_b xiv ...
Page 23: ...Model Selection SiUS34 801A_b 8 General Information ...
Page 133: ...Field Settings SiUS34 801A_b 118 VRVIII R 410A Heat Pump 60Hz ...
Page 254: ...SiUS34 801A_b Test Operation VRVIII R 410A Heat Recovery 60Hz 239 R 410A Label R 410A Label ...
Page 329: ...Field Setting SiUS34 801A_b 314 Indoor Unit ...
Page 340: ...SiUS34 801A_b Troubleshooting by Remote Controller Troubleshooting 325 ...
Page 490: ...SiUS34 801A_b Piping Diagrams Appendix 475 Heat Pump 230V RXYQ72 96 120PTJU 3D058636A ...
Page 491: ...Piping Diagrams SiUS34 801A_b 476 Appendix Heat Pump 230V RXYQ144PTJU 3D058640 ...
Page 492: ...SiUS34 801A_b Piping Diagrams Appendix 477 Heat Recovery 460V REYQ72 96 120PYDN 3D058639A ...
Page 493: ...Piping Diagrams SiUS34 801A_b 478 Appendix Heat Recovery 460V REMQ72PYDN 3D058637A ...
Page 494: ...SiUS34 801A_b Piping Diagrams Appendix 479 Heat Recovery 460V REMQ96 120PYDN 3D058638A ...
Page 495: ...Piping Diagrams SiUS34 801A_b 480 Appendix Heat Recovery 230V REYQ72 96 120PTJU 3D058639A ...
Page 496: ...SiUS34 801A_b Piping Diagrams Appendix 481 Heat Recovery 230V REYQ144PTJU 3D058640 ...
Page 497: ...Piping Diagrams SiUS34 801A_b 482 Appendix Heat Recovery 230V REMQ72PTJU 3D058637A ...
Page 498: ...SiUS34 801A_b Piping Diagrams Appendix 483 Heat Recovery 230V REMQ96 120PTJU 3D058638A ...
Page 501: ...Piping Diagrams SiUS34 801A_b 486 Appendix 1 3 BS Unit 4D057985A ...
Page 537: ...Piping Installation Point SiUS34 801A_b 522 Appendix ...
Page 543: ...Pressure Sensor SiUS34 801A_b 528 Appendix ...
Page 563: ...SiUS34 801A_b iv Index ...