Superheat Switch: Description and Operation
Superheat Switch and Thermal FuseThe superheat switch is located in the rear of the compressor in contact with the suction side gas, whose pressure drops and temperature rises with low refrigerant charge ( i.e. Freon leak). This condition closes the superheat switch contacts.
The thermal fuse is a sealed unit containing a heater and meltable fuse. The superheat switch brings in the heater which melts the fuse and disconnects the compressor clutch and heater. The compressor stops and damage from insufficient lubrication will be avoided.