What is the purpose of a crankcase heater on a compressor?

The purpose of a crankcase heater on a compressor is primarily to evaporate liquid refrigerant out of the compressor oil. When refrigerant accumulates in the oil, it can reduce the oil's lubricating properties and potentially lead to compressor damage or failure when the compressor starts. By heating the crankcase, the crankcase heater raises the temperature of the oil, allowing the refrigerant to vaporize and separate from the oil. This ensures that the compressor operates smoothly upon startup, as it maintains proper lubrication, reduces wear, and enhances overall reliability.

The other options do not accurately describe the primary function of the crankcase heater. While energy efficiency and overheating prevention are important in the overall operation of a compressor, they do not specifically relate to the direct function of the crankcase heater itself.