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Special Control
SiUS34-801A_b
202
VRVIII R-410A Heat Recovery 60Hz
7.3.2 Heating Oil Return Operation (including cooling / heating simultaneous
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.
*1: In case of multi outdoor unit system:
Master unit: It conducts the operation listed in the table above.
Slave units: Operating units conduct the operation listed in the table above.
Non-operating units conduct the operation listed in the table above after the
Oil Returning
process. Non-
operating units stop while in
Preparation
mode.
Actuator
Symbol
Elect. symbol
Oil return operation
REYQ
REMQ
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
M2F
Electronic expansion valve (main)
EVM
Y1E
Y3E
Y1E
20SA=ON : PI control
20SA=OFF : 418pls
Electronic expansion valve
(subcooling)
EVT
Y2E
Y5E
Y3E
PI control
Electronic expansion valve (refilling
refrigerant)
EVJ
Y4E
Y2E
80pls
Four-way valve (for heat changer
selection)
20SA
Y2S
Y9S
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.
Four-way valve (for high- and low-
pressure gas pipe selection)
20SB
Y8S
Y2S
OFF
Solenoid valve (main bypass)
SVE
Y5S
Y10S
Y6S
OFF
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
End conditions
•
Pe_min<31.9psi
•
After a lapse of 9 min.
OR
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 ...