The operating principle of the YS11 is both simple and effective.
At the heart of the protector is a Klixon® bimetal snapation disc.
When the temperature of this disc reaches its precalibrated temperature it snaps open, resulting in an open circuit.
This temperature is reached during a fault condition, caused by either an increase in ambient temperature, in increase in current flowing thru the disc, or a combination of both.
After the YS11 breaks the circuit, the system cools and the YS11 automatically resets allowing power to be restored in the circuit.