Miniature Circuit Breakers are classified according to tripping over range of fault current as the following.
Type B: this type of MCB trips between 3 and 5 times as full load current, type B devices are mainly used in residential applications or light commercial applications where connected loads are primarily lighting fixtures, domestic appliances with mainly resistive elements;
Type C: this type of MCB trips between 5 and 10 time as full load current,this is used in commercial or industrial type of applications where there could be chances of higher values of short circuit currents in the circuit;
Type D: this type of MCB trips between 10 and 20 times full load current. These MCBs are use in specialty industrial or commercial uses where current inrush can be very high;