What is a fuse?

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.

What happens if I install the wrong fuse?

Worst case scenario is damage to the equipment caused by a fault current or overload.
Other possibilities include the fuse blowing even though there is no electrical fault.
It is always best to replace a blown fuse with the same fuse or direct equivalent.

How do I decide which fuse I need?

1. When replacing original fuses, in most situations we can provide either the exact same fuse or an equivalent fuse produced by a different manufacturer.

2. When selecting a fuse for a new application, you need to consider many factors such as; element speed (ie. time/current curves), voltage, nominal current, ambient temperature, available space etc. We recommend you consult an electrical engineer to select a fuse for your application. Unfortunately we do not provide this service, but we can provide product data sheets to help you select a suitable fuse & holder. If you wish to learn more about fuse selection, please read our Understanding Overcurrent Circuit Protection datasheet from our product editorials.