Air Circuit Breaker ACB is an electrical device used to provide Overcurrent and short-circuit protection for electric circuits over 800 Amps to 10K Amps. These are usually used in low voltage applications below 450V. We can find these systems in Distribution Panels (below 450V). Here in this article, we will discuss the working of Air Circuit Breaker. Air circuit breaker is circuit operation breaker that operates in the air as an arc extinguishing medium, at a given atmospheric pressure. There are several types of Air circuit breakers and switching gears available in the market today that is durable, high-performing, easy to install and maintain. The air circuit breakers have completely replaced oil circuit breakers.