Firstly, when a fuse blows out, it takes quite some time to replace it and restore the power supply. Secondly, a fuse cannot successfully interrupt heavy fault currents that result from faults on modern high voltage and large capacity circuits. Due to this disadvantage, the use of fuse is limited to low voltage and small capacity circuits where frequent operations are not expected (i.e., for lighting circuits and branch circuits). Where a circuit breaker is much faster and reliable than a fuse.