ESCO Air Conditioning Practice Exam

In a split system, a crankcase heater is essential to prevent refrigerant migration to the compressor during the off cycle. This device keeps the oil in the compressor warm, preventing the refrigerant from mixing with the oil and causing potential damage to the compressor. The crankcase heater helps maintain the correct oil level in the compressor by preventing the refrigerant from condensing in the crankcase during the off cycle.

Liquid line solenoid, expansion valve, and filter dryer are important components in an HVAC system, however, they are not specifically designed to prevent refrigerant migration to the compressor during the off cycle. The crankcase heater serves this particular purpose and is crucial for the proper operation and protection of the compressor in a split system.