The Copeland 918-0043-00 Belt crankcase heater is a well workhorse heater for HVAC systems. During off cycles, the crankcase heater prevents the refrigerant migration to the compressor crankcase. It runs on 240V and has a power of 70 watts. It ensures that the crankcase remains warm preventing refrigerant dilution which may of course lead to compressor damage and loss of performance. ... https://www.partshnc.com/belt-240v-70w-crankcase-htr-6