So what is overcurrent? A very simple definition of overcurrent would be when excess electrical current, whether caused by lightning, electrical short, electromagnetic pulse (EMP) or other root source, is present in an electrical circuit. The problem with overcurrent is not the overcurrent itself, but rather the possible consequences of the overcurrent; damaged equipment, fire hazard, shock hazard, etc.

Overcurrent protection has many elements, beginning with the design of the electrical circuit, through the use of overcurrent protection hardware like cartridge fuses, fuse blocks, specialized fuse holders, terminal boards, and more.