Bimetal thermostats are normally closed (NC) and normally open (NO),They work the same principle,Just work the way it is the opposite.Sudden jump thermostat,Bimetal is the main temperature sensing element,When the heat generated by the heating element is transferred to the bimetallic wafer,Upon reaching operating temperature, the bimetal rapid action,By action mechanism, the contacts open or closed;When the temperature drops to the reset temperature setting,Bimetallic sheet quickly returned to its original state,The contact is closed or disconnected,By turning on or off the circuit,Control circuit.

While the normally closed bimetallic thermostat,When the appliance is working properly,Bimetal in an energized state,Contact is closed,When the temperature reaches the operating temperature,Bimetal sheet heat, resulting in internal stress and rapid action,Open contact,Cut off the circuit,Thus play a role in controlling the temperature.When the appliance is cooled to the reset temperature,Contact automatically closed,Return to normal working condition.Common KSD301, Ksd9700, there are often open and normally closed type.