Refrigeration systems that contain polyolester (POE) oil present technicians with concerns that aren’t normally found with systems that use mineral-based or alkylbenzene oils. Refrigeration technicians need to be aware of these issues while servicing and installing POE systems, to prevent system problems from developing.
When the motor of a hermetic compressor burns out, it is possible for contaminants to form in the compressor, depending on the severity of the motor burn. It is also possible for these contaminants to be pumped out into the system.
The only fluids circulating within a refrigeration system should be refrigerant and oil. Any other fluids contained within the system may reduce its capacity and possibly cause harm to the system. One common contaminant that can enter a system is atmospheric air.
To prevent overheating of a hermetic compressor’s internal motor, some type of cooling method must be employed. Compressor manufacturers will use one of three methods to provide the necessary cooling for their motors.
Understanding manufacturers' nomenclatures to identify their compressors can be a very useful tool for a service technician. There is much information about a compressor that can be obtained from decoding its model number.
While troubleshooting small-capacity refrigeration systems, a technician should not be too quick to attach refrigerant gauges to a system. Small systems normally hold relatively small amounts of refrigerant. The process of attaching and removing a set of refrigeration gauges will release a small amount of refrigerant from the system.
When installing walk-in coolers and freezers, the installing contractor will need to select the proper location of the condensing unit. Location is an important consideration for the success of the installation. There are several items to consider when selecting the location.
Many field-assembled refrigeration systems require the installing contractor or sales engineer to select the system components. Before any of the system components can be selected, however, the required Btu capacity of the system must be determined.
