BW-B Series Thermal Protector Working Principle：

Under normal conditions, the moving contact is in close contact with the stationary silver contact under the pre-pressure of the bimetal disc; When the rated operating temperature is reached, the bimetal disc is deformed by heat and snap rapidly, cut off the circuit. After that, the device begins to cool down. When it reaches the defined reset temperature, the bimetal disc and the spring disc snaps back into its start position, the contacts will close again, and the device starts working again.