Fuses

151.480600 Application Field and Working Principle

A fuse is a safety-device for protecting an electrical circuit from overloading. Fuses may be used both for residential and industrial electrical systems. In terms of size and weight, fuses are generally the smallest and lightest electrical protection option available in an electrical system. It is typically made of a metal strip, strip-like metal or wire wrapped around a thin metallic ribbon. Fuses come in a variety of shapes, sizes and designs to suit the specific circuit application.

The working principle of a fuse is that, when a certain amount of current passes through it, the heat generated from the current causes the fuse to expand and break. This safe guards the electrical system in two ways. Firstly, by interrupting the current, the malfunctioning appliance or circuit that was causing the excessive current flow is safely shut down. Secondly, depending on the type of fuse in use, if current continues to flow despite the interruption, the fuse will melt, and will act as a firebreak, preventing an electrical fire from occurring.

In industrial electrical systems, fuses are often used in combination with contactors, switches and sensors. This combination is beneficial when used to control hazardous voltage levels, as, should faults occur in the circuit, the fuse will break and prevent dangerous voltage levels from remaining within it. As a result, the fuse will ensure a high degree of electrical safety in industrial systems.

In residential systems, fuses are often used in combination with circuit breakers. Unlike a fuse, circuit breakers are designed to snap open and shut when there is a major surge in the current, hence providing additional protection in the event of a power surge. Whilst it is important to choose the correct type of fuse for the job, it is also worthwhile to install circuit breakers alongside the fuses as a precautionary measure.

Today’s modern fuses come in a variety of materials, such as aluminium, iron, copper and zinc. Different fuse types can also be used to protect specific parts of the electrical system. For example, a low voltage fuse might be used in motor applications, while a high voltage fuse may be utilised to protect large industrial units.

In conclusion, fuses are small but important components of electrical systems, acting to prevent electrical overloads that can lead to fires. Therefore, ensuring that the correct fuse type is installed in an electrical system is essential for keeping electrical systems safe.