Fuses are utilized to protect electrical circuits. This involves more than simply preventing the other electrical components within the circuit from being destroyed. It also provides an important measure of safety in areas where electrical devices are being operated.
The fuse will be placed in the electrical circuit so that it prevents many different types of disasters. The most obvious disaster is having an electrical appliance or another expense of electrical device get too much current and be destroyed. The other big hazard that a fuse prevents is an electrical fire. The fuse is designed to burnout before it reaches a temperature level that would present an actual hazard of fire – or melting damage – to the circuit or to the structure where the circuit is installed. This is most easily observable in household fuses, where the fuse will blow if too much current goes across the lines, preventing that current from heating up the electrical system in the house and causing fires behind the walls.
Fuses are given a current rating, which determines how much electrical current they can safely handle. Using a fuse that has too high of a rating for a given circuit can result in a situation where that circuit is, for all intents and purposes, not protected as it should be and, therefore, is subject to being damaged or to causing damage itself, in the event of an overcurrent condition.