How does air brake work?

Air switch is a kind of switch that will trip as long as there is a short circuit.

When the line is short-circuited or the current is seriously overloaded, the short-circuit current exceeds the instantaneous tripping setting current value, and the electromagnetic release generates enough suction force to attract the armature to impact the lever, so that the hook rotates upward around the rotating shaft seat and disengages from the lock catch, and the lock catch disconnects three pairs of main contacts and cuts off the power supply under the action of the reaction spring.

When the line is generally overloaded, the overload current can not make the electromagnetic trip work, but it can make the thermal element generate a certain amount of heat, make the bimetal bend upward when heated, push the lever to disengage the hook from the lock, disconnect the main contact and cut off the power supply.