Evaporator Temperature Sensor / Switch: Description and Operation

The anti-freeze thermostat is located above the evaporator casing. Its function is to prevent build up of ice between the evaporator cooling fins. A capillary tube is inserted in the evaporator and senses temperature. When temperature drops to about +1.5° C (34.7° F) the thermostat switches off the compressor. When temperature in the evaporator has then risen to about +4.5° C (40.1° F), the compressor is again switched on.