A fuse is an electrical component designed to protect electrical circuits by safely opening the circuit under abnormally high current loads. Fuses come in many shapes and sizes, but each one is designed to protect a circuit with a specific set of electrical parameters. These parameters are primarily the operating voltage, operating current and fuse element melting time or speed of the fuse.

How does a fuse work?

A fuse contains a metal element which is designed to carry a limited electrical current. When a short circuit or overload occurs, the higher current will generate heat causing the fuse element to melt and create a gap in the fuse element. This gap breaks the current flow through the fuse (and circuit). A fuse must be replaced once it has blown.