An air circuit breaker is a electrical device design to supply three stage overcurrent protection, undervoltage protection and earthing protection on low voltage distribution circuit. The range of rate current is from 630 A to 6300 A. Thus, it is mainly applied as the main circuit breaker in input panels or as the high power protection device in feeder panels.
On voltage range, an air circuit breaker ACB designs to use on low voltage electrical circuit, and a vacuum circuit breaker designs to use on medium voltage power distribution line.
On implementing functions, an air circuit breaker ACB has build in trip coils to fulfil protection functions such as three stage overcurrent protection and ground fault. However, besides the short circuit breaker protection, an vacuum circuit breaker fulfills protection functions depends on the independent relay system, such as overload protection and ground fault.
On arc extinguishing, an air circuit breaker ACB take atmosphere to extinguish the arc through arc chutes.However, a vacuum circuit breaker VCB create a vacuum working condition to extinguish the arc through vacuum interrupter.
