It can be stated that the process of a short circuit refers to a connection without resistance, occurring between conductors under voltage, and may also be an intentional or accidental connection between two points of the same system or some electrical equipment, or a component, by means of an impedance considered undesirable. Thus, under these conditions, through a negligible transient resistance, the current may assume a value many times higher than the operating current, so that the device and part of the installation may undergo a thermal stress, a bearable current or an electrodynamic, a nominal current of excessive impulse.
In the case of components called fuses, their operation is due to the fusion of an element by the Joule effect, generated by the sudden increase of current in a given circuit 81000 OHP. The fuse element has physical properties, that its melting point is less than the melting point of the copper. Basically, fuses are elements used for the main purpose of limiting the current of an existing circuit, thus providing for its interruption in case of short circuits or long overloads, for example.