TRUE PARTS 800360 THERMOSTAT DEFROST 37T21 (800360)

The defrost mechanism in a refrigerator heats the cooling element evaporator coil for a short period of time and melts the frost that has formed on it. The resulting water drains through a duct at the back of the unit. Defrosting is controlled by an electric or electronic timer For every 6, 8, 10, 12 or 24 hours of compressor operation it turns on a defrost heater for 15 minutes to half an hour. A defrost thermostat opens the heater circuit when the evaporator temperature rises above a preset temperature, 40 deg F 5 deg C or more, thereby preventing excessive heating of the freezer compartment. The defrost timer is such that either the compressor or the defrost heater is on, but not both at the same time. A thermostat is a component which senses the temperature of a physical system and performs actions so that the systems temperature is maintained near a desired setpoint by controlling the supply of gas or electricity to the heating or cooling system. Thermostats are used in any device or system that heats or cools to a setpoint temperature. A thermostat operates as a closed loop control device, as it seeks to reduce the error between the desired and measured temperatures. Sometimes a thermostat combines both the sensing and control action elements of a controlled system. A thermostat exerts control by switching heating or cooling devices on or off, or by regulating the flow of a heat transfer fluid as needed to maintain the correct temperature. A thermostat can often be the main control unit for a heating or cooling system including central heating, air conditioners, as well as kitchen equipment including ovens and refrigerators. Features. Defrost 37T21 Thermostat. Made with high quality material