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Special Control
SiUS34-801A_b
206
VRVIII R-410A Heat Recovery 60Hz
7.5.1 Pump-down Residual Operation in Cooling Operation
If the liquid refrigerant stays in the Evaporator at the startup of a compressor, this liquid refrigerant enters the compressor,
thus resulting in diluted oil in the compressor and then degraded lubrication performance.
Consequently, in order to recover the refrigerant in the Evaporator while the compressor stops, the pump-down residual
operation is conducted.
*
Pe_min and Pc_max indicate the minimum and maximum values in the system, respectively.
Actuator
Symbol
Elect.
symbol
Master unit operation
Slave unit operation
REYQ
REMQ
Compressor 1
—
M1C
M1C
124 Hz+OFF
OFF
Compressor 2
M2C
M2C
Outdoor unit fan 1
—
M1F
M1F
Fan control
Fan control
Outdoor unit fan 2
M2F
M2F
Electronic expansion valve (Main)
EVM
Y1E
Y3E
Y1E
1375 pls
1375 pls
Electronic expansion valve
(Subcooling)
EVT
Y2E
Y5E
Y3E
0 pls
0 pls
Electronic expansion valve
(Refrigerant charge)
EVJ
Y4E
Y2E
80 pls
80 pls
Four-way valve (Heat exchanger
switch)
20SA
Y2S
Y9S
Y3S
OFF
OFF
Four-way valve (High/low
pressure gas pipe switch)
20SB
Y8S
Y2S
ON
ON
Solenoid valve (Main bypass)
SVE
Y5S
Y10S
Y6S
ON
ON
Solenoid valve (Hot gas)
SVP
Y4S
Y5S
OFF
OFF
Solenoid valve (Refrigerant
regulator liquid pipe)
SVL
Y3S
Y4S
OFF
OFF
Solenoid valve (Refrigerant
regulator gas vent pipe)
SVG
Y1S
Y1S
OFF
OFF
Solenoid valve (Refrigerant
regulator exhaust pipe)
SVO
Y7S
Y7S
OFF
OFF
Solenoid valve (Refrigerant
regulator discharge pipe)
SVT
Y6S
Y8S
OFF
OFF
Ending conditions
•
5 min.
•
Pe_min<71.05psi
∗
•
Pc_max<426.3psi
∗
•
Master unit Tdi>230
°
F
•
Master unit Tp>257
°
F
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 ...