Too often, compressors get replaced when an external component, such as a defective start relay, start capacitor, or overload, is the true cause. A technician must always check these components before condemning the compressor.
Measuring the evaporator’s superheat value is an important part of analyzing a system’s performance. If a lower-than-normal value is measured, too much refrigerant is entering the evaporator for the heat load. If a higher-than-normal value is measured, too little refrigerant is entering the evaporator for the heat load.
Choosing the correct line size is very important to the overall success of the installation. Incorrectly sized refrigerant lines can lead to system problems, excessive energy consumption, and higher installation and operation costs.
For maximum efficiency, a bank of compressors should be connected to evaporators operating at similar temperatures. From an operational standpoint, cases of different evaporating temperatures can be connected to the rack; however, this causes a substantial energy loss.