2070.0012.11 Circuit Protection

Fuses

2070.0012.11 Application Field and Working Principle

A fuse is one of the most well-known electrical components used in electrical and electronic circuits. Its main function is to protect these circuits from overcurrent caused by electrical overload or short circuit. A fuse is a sacrificial device that will automatically disconnect when its capacity is exceeded, thereby protecting other components in the circuit, such as transformers, motors, and other electrical elements, from damage caused by electric current.

Fuses come in various shapes, sizes, and materials, with some being designed to protect a specific type of circuit or element. Generally though, a fuse has two conductive metal elements, one of which will be a strip or wire, which is called a fuse element. This fuse element is connected to a contact on the other end of the fuse, which can be either a contact plate or a screw terminal.

When a fuse is used in an electrical circuit, when current passes through it, the contact plate or screw terminal will be connected to each other as long as the current remains below the rating of the fuse. This means that current can freely flow through the circuit without any danger of overload. However, if the current passing through the circuit exceeds the rated value of the fuse, the heating effect on the fuse element will cause it to melt, disconnecting the contact and thereby breaking the circuit.

This breaking of the circuit will not only protect the electrical elements in the circuit, but also the user. This is why the fuse is an important safety device in an electrical circuit, as it will provide protection against harmful electrical shock that can occur as a result of an overload or short circuit.

Fuses are not only used to protect circuits from overcurrent, but also to protect them from other things. For example, they can also be used to protect against ground fault current, which can occur when a live conductor touches a grounded conductor, as well as to provide protection from lightning strikes.

When it comes to choosing the right fuse for a particular application, there are several factors to consider, such as the voltage and current ratings of the fuse, as well as any other special requirements that may be specific to the application. The fuse should always be rated to handle the current required by the application, so that it can activate in time to protect the circuit.

Fuses are also available in different types, such as time-delay fuses, thermal fuses, and variable fuses, so the type of fuse used in a particular application should depend on the type of circuit or element it is used to protect. However, in most cases, the traditional strip fuse is the preferred type, since it is quite reliable and relatively low cost.

In conclusion, fuses are an essential part of any electrical system, providing protection from electric shock and short circuits, as well as protecting other electrical components from damage. They are available in a wide variety of sizes, styles, and materials, making it easy to find a fuse that is suitable for your particular application. It is important to remember to always choose a fuse that is correctly rated for the current requirements of the application, in order to ensure that it provides adequate protection.