Check For Overcharge Of Refrigerant; Diagnosis Of Overcharge Of Refrigerant - Daikin VRVII Manual

Troubleshooting by Indication on the Remote Controller
CHECK 6
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 judgement, 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 superheated 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 subcooling section becomes
lower.
Cooling
High pressure
Low pressure
Frequency

Check for overcharge of refrigerant.

High pressure
gradually rises with
increase in
frequency.
(Low pressure is
maintained at a
constant level.)
To maintain low pressure, frequency
increases under the capacity
control.
High pressure
drooping control
Frequency comes to
the minimum level.
Subcooled degree
becomes higher.
(Liquid connection
pipe temperature
lowers.)
Low pressure rises due
to decreased
compressor output.
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