What is the function of a crankcase heater in refrigeration systems?

The function of a crankcase heater in refrigeration systems is primarily to prevent refrigerant migration to the compressor crankcase during the off-cycle. When the system is not running, refrigerant can migrate from the evaporator to the compressor crankcase due to gravity or pressure differentials. If a significant amount of liquid refrigerant collects in the crankcase, it can lead to compressor flooding when the system starts up again.

A crankcase heater warms the compressor, maintaining a temperature that prevents refrigerant from condensing and migrating back into the crankcase. This is crucial for ensuring that only vapor enters the compressor during the start-up phase, which helps to avoid damage and operational issues.

The other options present alternative scenarios that are not the main function of a crankcase heater. For instance, while managing superheat and preventing flooding are important in overall compressor performance, they are not directly related to the primary role of the crankcase heater. This specialized component specifically addresses the issue of refrigerant migration during the off-cycle, helping maintain the longevity and efficiency of the refrigeration system.