Current limiting fuses can reduce both the magnitude and duration of a fault current. A UL Listed, current limiting fuse must clear a short circuit current in less than one half cycle in its current limiting range. In this condition the fuse will melt in the first quarter cycle and prevent the fault current from reaching the first peak of the asymmetrical waveform, significantly limiting the total electrical energy delivered to the fault. This energy limitation enables class J, RK1, T and L fuses to reduce incident heat energy from an arc flash to very low levels.