SiUS281811EA
Check
Part 6 Service Diagnosis
297
5.6 Refrigerant Shortage Check
CHECK 7
The only way to judge as the shortage 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 shortage of refrigerant
1. The superheated degree of suction gas rises. Consequently, the compressor discharge gas
temperature becomes higher.
2. The superheated degree of suction gas rises. Consequently, the electronic expansion valve
turns open.
3. Low pressure drops to cause the unit not to demonstrate cooling capacity (heating capacity).
Cooling
High pressure
Low pressure
Frequency
The opening degree of the indoor unit
electronic expansion valve becomes
larger.
Either of the electronic expansion
valves becomes fully open.
Frequency comes to the minimum level.
Fan control is activated for high
pressure protection under
cooling control at low outdoor
air temperature, i.e., the fan is
hunting at high pressure.
High pressure drops
with decrease in
compressor capacity.
If frequency comes to the
minimum level, low
pressure cannot be
maintained.
Low pressure rises as the
opening degree of the indoor
unit electronic expansion
valve becomes larger.
Frequency slightly increases
under the capacity control.
To maintain low
pressure,
frequency drops
due to the
capacity control.
Heating
High pressure
Low pressure
Frequency
The opening degree of the outdoor unit electronic expansion valve becomes larger.
The outdoor unit electronic expansion valve fully opens and frequency increases.
Discharge pipe or low pressure dropping control
(High pressure
is maintained at
a constant
level.)
To maintain low pressure,
frequency drops due to the
capacity control.
Frequency drops
due to the dropping
control.
(Degree of refrigerant shortage)
Higher degree of shortage
Proper amount
(Low pressure
is maintained at
a constant
level.)
Frequency comes to
the minimum level.
Summary of Contents for SkyAir RZR-TA Series
Page 1: ...Service Manual Cooling Only 60 Hz Heat Pump 60 Hz RZR TA RZQ TA Series SiUS281811EA...
Page 202: ...SiUS281811EA 196 Part 6 Service Diagnosis 5 15 Fan Motor Connector Check for FTQ TA 311...
Page 323: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 317 RZR18 24TAVJUA RZQ18 24TAVJUA 3D124495...
Page 327: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 321 FHQ18 24 30PVJU FHQ36 42MVJU 3D048116C...
Page 328: ...Wiring Diagrams SiUS281811EA 322 Part 7 Appendix FAQ18 24TAVJU 3D114844B...
Page 329: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 323 FBQ18 24 30 36 42 48PVJU 3D065984J...