In medium- and low-temperature refrigeration applications, 1 hp is hardly ever equal to 1 ton of refrigeration. Let’s review a few principles to illustrate this point.

A refrigeration system can be a major draw on electrical energy, so it can be a real benefit when a technician also can make sure the system is operating efficiently. 

These larger refrigeration systems present tremendous opportunities for energy-efficiency improvements that can lead to significant operational savings.

Remember, when wiring motors for a certain voltage, the service technician must always refer to the motor manufacturer’s literature and numbering scheme before wiring the motor for the desired voltage or damage to the motor’s windings may occur.

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.

Voltage unbalances exceeding more than 2 percent in three-phase systems can cause current unbalance among the windings. These voltage and current unbalances can cause an increase in winding temperature and an overheating problem that can be detrimental to the motor.

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. 

The aggressive environmental and regulatory positions in Sacramento have caused the rest of the U.S. to monitor policymaking and enforcement out West. And, more often than not, those policies have ended up as the blueprint for federal regulations.

CO₂ is primarily used in cascade systems that include ammonia, in booster systems in supermarkets, and as a stand-alone refrigerant for transcritical-configured systems.

Supermarket owners want refrigeration systems that are energy efficient to hold down costs and pro-environmental to portray political correctness. But, for engineers, contractors, and technicians, that approach may not be that easy when opening a new store or retrofitting an existing location.