Articles by Joe Marchese
May 3, 2010
Refrigeration technicians carry refrigerant in non-refillable cylinders on their service vehicles every day. While these cylinders are considered relatively safe, there are some hazards associated with transportation and storage, and when removing refrigerant. Mishandling or improper use can lead to injury and/or property damage.
April 5, 2010
The required oil charge for a system is basically a factor of the amount of refrigerant in the system and the compressor’s oil pumping rate. The most common method of determining if oil needs to be added to a compressor is to observe the compressor’s oil sight glass. But what if the compressor doesn’t have an oil sight glass?
March 8, 2010
Servicing and maintaining refrigeration systems requires a technician with a unique set of skills. Not only must a technician be proficient in the refrigerant cycle and all of its components, they also must be knowledgeable in many other trades.
February 1, 2010
Certifications offer many benefits to a technician. First, taking a certification exam demonstrates that a technician is serious about his trade and, more importantly, if passed, that he has achieved a high level of expertise. Certifications can also be used as a self-check to identify areas of weakness or strength.
January 11, 2010
One contaminant that must be removed from a refrigeration system before refrigerant can be added is water vapor. If water vapor is left trapped in a system, it can lead to some serious problems. Technicians will typically reduce the system’s pressure to about 500 microns to remove this water vapor.
December 7, 2009
There are several ways we can get answers to our questions. The easiest way is to just ask someone who has more experience with the system or component. However, if an answer does not make sense or is unclear, we should not just simply accept it as fact, but should ask it again or ask “why.”
November 2, 2009
Thermistors are one type of temperature sensor used on electronic control systems. Technicians servicing these control systems need to be able to test the operation and accuracy of these sensors. A defective thermistor can easily cause a controller to not operate correctly.
October 5, 2009
An oil separator is an accessory used on some larger refrigeration systems to help limit the amount of oil in circulation. It is typically used on low temperature applications where the refrigerant’s mass flow rate is low. But it could be used on any system.
September 7, 2009
Troubleshooting a refrigeration system is all about gathering information and using that information to determine the cause of a problem. Technicians are always measuring voltages, amperages, pressures, and various temperatures to help them find a problem. Besides these important measurements, there are other pieces of information that can assist a technician.
August 3, 2009
One of the common problems found while troubleshooting reciprocating compressors is that they simply fail to start. This could be the result of many different causes, both electrical and mechanical. One common mechanical cause is a stuck piston. Mechanically the piston cannot overcome an internal resistance to move.