Exam Question

### (a) How would you know a Refrigeration system is 'undercharged'?
An undercharged refrigeration system indicates an insufficient amount of refrigerant circulating within the system, leading to a reduction in cooling capacity and various observable symptoms. A Senior MEO Class 1 Examiner would identify an undercharged system by observing the following:
* **Low Suction Pressure**: The compressor suction pressure (evaporator pressure) will be lower than normal. This is because less refrigerant is boiling off in the evaporator, leading to a reduced pressure drop across the expansion valve and lower vapor density entering the compressor.
* **Low Discharge Pressure**: The compressor discharge pressure (condenser pressure) will also be lower than normal. With less refrigerant circulating, the mass flow rate through the condenser is reduced, resulting in less heat rejection and a lower condensing temperature and pressure.