SiUS371901E
Check
Service Diagnosis
382
4.5
Refrigerant Overcharge Check
In case of
VRV
Systems, the only way to judge as the overcharge of refrigerant is with operating
conditions due to the relationship to pressure control and electronic expansion valve control.
As information for making a judgment, refer to the information below.
Diagnosis of overcharge of refrigerant
1. High pressure rises. Consequently, overload control is conducted to cause insufficient cooling
capacity.
2. The superheating degree of suction gas lowers (or the wet operation is performed).
Consequently, the compressor becomes lower in discharge pipe temperature despite of
pressure loads.
3. The subcooling degree of condensate rises. Consequently, in heating, the temperature of
discharge air through the subcooled section becomes lower.
CHECK 6
Cooling
High pressure
Low pressure
Frequency
High pressure
gradually rises with
increase in
frequency.
Subcooling degree
becomes higher.
(Liquid connection
pipe temperature
lowers.)
Low pressure rises due
to decreased
compressor output.
High pressure
Low pressure
Frequency
Heating
The outdoor unit electronic expansion valve
is closed due to the overload control.
Frequency comes to
the minimum level.
(
High pressure
is maintained
at a constant level.)
Low pressure
rises
due to
decreased
frequency.
To maintain
high pressure
,
frequency
decreases
under the
capacity control.
High pressure
drops or rises
immediately after the overload
control is complete.
Low pressure
drops due to
closed outdoor unit
electronic expansion valve.
Hot gas bypass is activated
for
low pressure
protection,
i.e., hunting at
low pressure
.
Higher degree of overcharge
(Degree of overcharge)
Proper amount
To maintain low pressure, frequency
increases under the capacity
control.
Frequency comes to
the minimum level.
High pressure
dropping control
(Low pressure is
maintained at a
constant level.)
Summary of Contents for REYQ72-456XATJU
Page 415: ...SiUS371901E Wiring Diagrams Appendix 402 REYQ144 168XATJU 2D119206A ...
Page 416: ...Wiring Diagrams SiUS371901E 403 Appendix REYQ72 96 120XAYDU 2D119207B ...
Page 417: ...SiUS371901E Wiring Diagrams Appendix 404 REYQ144 168XAYDU 2D119208B ...
Page 418: ...Wiring Diagrams SiUS371901E 405 Appendix REYQ72 96 120 144 168XAYCU 2D119209A ...
Page 421: ...SiUS371901E Wiring Diagrams Appendix 408 FXZQ05 07 09 12 15 18TAVJU 3D110443A ...
Page 423: ...SiUS371901E Wiring Diagrams Appendix 410 FXEQ07 09 12 15 18 24PVJU 3D098557A ...
Page 426: ...Wiring Diagrams SiUS371901E 413 Appendix FXMQ07 09 12 15 18 24 30 36 48 54PBVJU 3D093209B ...
Page 428: ...Wiring Diagrams SiUS371901E 415 Appendix FXHQ12 24 36MVJU 3D048116C ...
Page 429: ...SiUS371901E Wiring Diagrams Appendix 416 FXAQ07 09 12 18 24PVJU C 3D075354D ...
Page 435: ...SiUS371901E Wiring Diagrams Appendix 422 VAM1200GVJU 3D073270D ...
Page 437: ...SiUS371901E Wiring Diagrams Appendix 424 1 4 2 Multi Branch Selector Unit BS4Q54TVJ 3D089123B ...
Page 438: ...Wiring Diagrams SiUS371901E 425 Appendix BS6 8Q54TVJ 2D089122B ...
Page 439: ...SiUS371901E Wiring Diagrams Appendix 426 BS10 12Q54TVJ 2D089121B ...
Page 440: ...Revision History Month Year Version Revised contents 04 2019 SiUS371901E First edition ...
