An air switch, also known as an air circuit breaker, is a type of circuit breaker. It is a switch that automatically disconnects as long as the current in the circuit exceeds the rated current. The air switch is a very important electrical appliance in the low-voltage distribution network and electric drive system. It combines control and multiple protection functions. In addition to the ability to complete contact and disconnect circuits, it can also protect against short circuits, severe overloads and undervoltages in circuits or electrical equipment, and can also be used to start the motor infrequently.
There are three types of air circuit breaker tripping methods: thermal, electromagnetic and double tripping.
When the line is generally overloaded, the overload current can not make the electromagnetic release action, but can cause the heat element to generate a certain amount of heat, causing the bimetal to be bent upwards by heating, pushing the lever to disengage the hook from the lock, and the main touch The head is broken and the power is turned off. When the line is short-circuited or severely overloaded, the short-circuit current exceeds the instantaneous trip setting current value, and the electromagnetic tripper generates a sufficient suction force to attract the armature to the impact lever, causing the hook to rotate upwardly around the shaft seat and disengage the lock. The lock buckles the three main contacts under the action of the reaction force spring to cut off the power.