Refrigeration & Oil
Oil is an important part of many pieces of machinery, and a refrigeration compressor is no exception. Oil provides the much-needed lubrication for moving parts within the compressor. The oil can also be cooled to help prevent internal components from overheating. Additionally, oil helps seal very small gaps between moving parts or gaskets to make a more complete closure between the components.
We can probably agree that oil is an important part of the system, so how can we manage it? One of the battles most technicians are familiar with is battling to keep oil within the compressor or at least returning to the compressor. Oil separators are efficient at keeping oil from escaping the compressor via the discharge line and emerging out into the system, but they aren’t perfect. Proper piping techniques such as appropriately placed pipe traps will help keep the oil that escapes the oil separator moving through the refrigeration cycle and back to the compressor. Those who have emptied an oil pot, on a Low temperature recirculator for example, will note that the system is not perfect at cycling the oil, and oil is regularly trapped and lost. This is particularly true in ammonia refrigeration systems. Therefore, routine maintenance to ensure proper oil levels in refrigeration compressors is still required. Operating a compressor without oil can quickly and irreversibly damage the machine.
Making sure the compressor has sufficient oil isn’t enough on its own. We must also make sure the oil is clean and properly formulated. Regularly serviced oil filters can help catch and remove debris in the system. After the system is in operation, it’s important to take samples to monitor the health of the oil in the system. Oil is commonly taken from an oil pot or an oil separator and sent to a lab to be tested for various abnormalities. The lab can detect many problematic oil conditions such as water inclusion, the inclusion of metal shavings or other debris, acidity, or abnormal viscosity. The lab tests can indicate if the oil has been damaged in some way, such as by excessive heat. Damaged oil would indicate a problem within the system that needs attention.
Oil level monitoring and oil analysis are helpful tools in keeping our refrigeration systems running properly. Routine oil sampling in conjunction with properly monitoring and maintaining oil levels is a fantastic way to ensure your system continues to run properly. If you’d like to add oil sampling to your preventative maintenance program, feel free to reach out to Carlson and Stewart Refrigeration for more information. CSR also sells oil, filters, and has 24/7 service available should your freon or ammonia system find itself in need of some assistance.