If the refrigeration compressor is equipped with an oil sump heater, what must be ensured about the oil temperature?

The refrigeration compressor's oil sump heater is designed to maintain the oil at a temperature sufficient to drive off any refrigerant that may be dissolved in it. This is crucial because refrigerant in the oil can lead to decreased lubrication effectiveness, which may cause compressor damage or efficiency loss.

When the oil temperature is high enough, it aids in the separation of any refrigerant that has mixed with the oil during operation. This separation prevents refrigerant dilution of the oil, helping to maintain proper lubrication properties and ensuring efficient compressor operation.

In contrast, maintaining low oil temperatures could lead to refrigerant retention in the oil, while being at room temperature might not be effective for ensuring proper lubrication. Having a constant temperature is not the primary concern; rather, reaching the appropriate temperature threshold to expel refrigerant is critical. Thus, ensuring that the oil temperature is sufficiently high to drive off any refrigerant is essential for the longevity and performance of the refrigeration system.