Main parts

1) Shell  2) Base  3) Bimetal disc  4) Movable contact

5) Temperature calibration plate  6) Static contacts

Construction

The movable contact are welded to the bimetal sheet and then wel-

ded to the iron bracket. The stationary silver contact and base are 

molded into a whole, after the current passes through the temper-

ature calibration plate and the bimetal disc, it forms a loop from the 

moving contact to the static contact.

Function

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.