John Tomczyk is HVACR professor emeritus, Ferris State University, Big Rapids, Michigan, and coauthor of Refrigeration & Air Conditioning Technology, published by Cengage Learning. Contact him at firstname.lastname@example.org.
There are several reasons why a refrigeration or air conditioning system may have high compressor discharge temperatures. That’s why technicians must carefully measure the system’s temperatures and pressures to determine the problem.
There are several reasons why the compressor discharge temperature of a refrigeration system can be high when the condensing temperature is not, and a checklist can help a technician figure out the root problem.
If a potential relay is malfunctioning, the compressor motor is in danger of not starting, stalling, locking rotor, or even burning out. That is why technicians should understand how to troubleshoot potential relays.
The HVACR industry will soon be using low-GWP refrigerant blends, some of which have a temperature glide when evaporating and condensing. As these refrigerant blends change phase, there’s a change in their composition, which technicians must be able to calculate while in the field.
One of the worst enemies of a compressor is liquid refrigerant, so technicians should make sure the refrigeration system has proper superheat in order to protect the compressor from damage that can occur from flooding or slugging.
Making sure the TXV is metering the right amount of refrigerant into the evaporator and is not overfeeding the coil is one way technicians can help their customers’ refrigeration and air conditioning systems operate safely and more efficiently.