1. Air switch
An air switch, also known as an air circuit breaker, is a type of circuit breaker. It is a power switch that automatically cuts off only when the current in the circuit exceeds the rated voltage. The air switch is a very important electrical appliance in the distribution room network and power drag system. It integrates control and various maintenance. In addition to touching and disconnecting the power circuit, it may also cause short-circuit faults in the power circuit or electrical equipment. More serious overload and under-voltage protection can also be used for infrequent motor operation.
When the distribution line is generally overloaded, although the overload current cannot make the electromagnetic buckle position, it will cause the thermal element to generate a certain amount of heat, which will cause the bimetallic sheet to bend upward when heated, and the push rod will release the hook and lock, breaking the main contact ,cut the power. When a short circuit or a severe overload current occurs in the distribution line, the current exceeds the set current value of the instantaneous trip, and the electromagnetic release generates enough suction force to attract the armature and hit the lever, so that the hook rotates up around the shaft seat and the lock is released. Open, the lock will disconnect the three main contacts under the action of the reaction spring, and cut off the power supply.
2. Main role
Under normal circumstances, the armature of the overcurrent release is released; once a serious overload or short-circuit fault occurs, the coil connected in series with the main circuit will generate a strong electromagnetic attraction to attract the armature downward and open the lock hook. Open the main contact. An undervoltage release works just the opposite. When the working voltage is normal, the electromagnetic attraction attracts the armature, and the main contact can be closed. Once the operating voltage is severely reduced or the power is cut off, the armature is released and the main contacts are opened. When the power supply voltage returns to normal, it must be re-closed before it can work, which realizes the voltage loss protection.