Thermal Limiting Fuse: Description and Operation

Superheat Switch and Thermal Fuse

Jaguar used a GM type thermal limiter and super heat switch into 1986 model year. If your unit does not have a thermal limiter mounted at the upper left front area of the compressor, see High_Side Low Pressure Switch. Low Pressure Sensor / Switch

These units are included in the compressor clutch circuit to provide protection against low refrigerant charge and blockages causing extreme superheated inlet gas conditions that result in compressor damage.

The 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 camage from insufficient lubrication will be avoided.

CAUTION: After a thermal fuse melt, establish and rectify the cause before replacing the thermal fuse unit complete.