After the electric kettle is connected to the power supply for heating, the water temperature rises to 100 degrees. Due to thermal expansion and cold contraction, the bimetal expands and deforms, and the switch contact is lifted to disconnect the power supply.
If the steam switch fails, the water in the kettle will continue to boil until the water is dry and the temperature of the heating element will rise sharply. The two bimetals at the bottom of the heating plate rose sharply due to heat conduction, expanded and deformed, and cut off the power supply. So the safety protection device of electric kettle is very scientific and reliable. This is also the principle of triple safety protection of electric kettle.