Air circuit breakers (ACBs) are designed in a range of ratings so that they can be tailored to different applications and fault conditions. Their capacity ratings generally fall into two categories: the rated current (or operating current), which indicates the maximum current the ACB can carry under normal conditions, and the interrupting (short-circuit) capacity, which specifies the maximum fault current the device can safely break.
Capacity Ranges of Air Circuit Breakers
ACBs are primarily used in low-voltage and medium-voltage applications. Their current ratings typically fall within these ranges:
Low-voltage applications: 630A to 6,300A
Medium-voltage applications: Up to 12kV (though ACBs are more common in LV systems)