Air Circuit Breaker (ACB) is one type of electrical protection device commonly used in electrical systems. Air Circuit Breaker is an electrical protection device used to cut off the flow of electricity in an electrical circuit when there is a disturbance or excess current. This tool is generally used in industrial electrical panels and can be used in electrical systems with quite high voltage.

Air Circuit Breaker works by cutting off the flow of electricity in an electrical circuit when there is a disturbance or excess current. Air Circuit Breaker uses a special system consisting of several components, such as trip unit, operating mechanism, and current transformer. When there is a disturbance in an electrical circuit, the trip unit will detect excess current. Then, it gives a signal to the operating mechanism to cut off the flow of electricity in the circuit. After the electric current is cut off, Air Circuit Breaker will extinguish the arc that occurs using the arc extinguishing system that has been prepared.

The main function of Air Circuit Breaker is to protect electrical equipment and systems from damage due to over current or excess current, which usually occurs due to short circuit or overload.