Check
SiME281906E
203
Part 6 Service Diagnosis
6.10 Refrigerant Overcharge Check
CHECK 12
As criteria for judging whether refrigerant is excessively charged or not, refer to the following
operating conditions.
1. Because high pressure rises due to excessive charging, overload control is carried out and
capacity tends to run short.
2. Considering pressure load, compressor discharge pipe temperature is low.
Compressor frequency
increases in order to
maintain low pressure.
Cooling
Adequate level
Maximum frequency
Suction superheating degree is approx. 0 deg.
(Degree of excessive refrigerant charging)
As compressor
frequency decreases,
low pressure rises.
Compressor frequency
decreases due to high
pressure protection control
Minimum frequency
Electronic expansion valve
opening degree decreases
due to wet protection control
Minimum opening degree
Excessive charge
High pressure
(Heat exchanger middle
thermistor)
Low pressure
(Pressure sensor)
Compressor
frequency
Electronic
expansion valve
Suction
superheating degree
Discharge
superheating degree
