Daikin SkyAir RZQ200 · 250C7Y1B Service Manual page 193

Diagnosis by Remote Controller
Check No. 9 Check for excessive refrigerant charging
As criteria for judging whether refrigerant is excessively charged or not, refer to the following
operating conditions.
<Diagnosis of excessive refrigerant charging>
In cooling operation
(1) Because high pressure rises due to excessive charging, overload control is carried out and
(2) Considering pressure load, compressor discharge pipe temperature is low.
(3) Subcooled degree of condensate liquid becomes large. Therefore, temperature of blown air
superheat degree
superheat degree
182
capacity tends to run short.
passing through subcooled part decreases in heating operation.
Cooling
High pressure
Low pressure
Compressor
frequency
Compressor frequency
increases in order to
maintain low pressure.
Electronic
expansion valve
Suction
Suction superheat degree is approx. 0 deg.
Discharge
Adequate level
Heating
High pressure
Low pressure
As compressor
frequency decreases,
low pressure rises.
Compressor
frequency
Compressor frequency
decreases in order to
maintain high pressure.
Electronic
expansion valve
Suction Suction superheat degree is approx. 0 deg.
superheat degree
Discharge
superheat degree
Adequate level
As compressor
frequency decreases,
low pressure rises.
Compressor frequency
Maximum frequency
decreases due to high
pressure protection control
(Degree of excessive refrigerant charging)
(Degree of excessive refrigerant charging)
SiBE26-701
Minimum frequency
Electronic expansion valve
opening degree decreases
due to wet protection control
Minimum opening degree
Excessive charge
Minimum frequency
Electronic expansion valve
opening degree decreases
due to wet protection control
Minimum opening degree
Excessive charge
Troubleshooting