A fuse provides overcurrent protection of a load or source circuit as a low-resistance resistor. It requires a metal wire or strip that melts when too much current flows, which interrupts the circuit the fuse is in. Overloading, mismatched load, short circuits or device failure are common causes of too much current.
When a fuse blows, it interrupts the current preventing fire or overheating. Therefore, fuses are essential in electrical systems. Fuses do this by melting at a lower temperature than the wire. Once the fuse is melted, the current will not flow and therefore the fuse has broken the circuit.
Fuses come in a variety of sizes and styles. However, each type has a standard pakage to be interchangable. The element of a fuse is can be made of zinc, copper, silver, aluminum, or alloys to provide consistent characteristics.