In terms of oil cooler performance, what is the main indication of proper functioning?

The main indication of proper functioning of an oil cooler is the effective removal of heat from the oil. An oil cooler's primary purpose is to lower the temperature of the oil circulating within the refrigeration system to ensure optimal performance of the compressor and other components. When the oil cooler operates effectively, it efficiently transfers heat away from the oil, leading to lower oil temperatures and improved lubrication properties. This is crucial for maintaining equipment reliability and preventing overheating, which can lead to equipment failure.

Although a higher temperature differential might suggest some degree of cooling, it does not directly indicate the effectiveness of the cooler without considering how much heat is being removed. The low pressure on the high side and increased suction temperatures are generally indicators of other operational issues and do not reflect the oil cooler's performance specifically. Proper functioning is best indicated by the successful reduction of oil temperature, confirming that the oil cooler is removing heat as intended.