Components and uses of drop out fuses

By | February 1, 2017

Drop out fuse is a combination of fuse and switch. This is used to protect the electrical equipment from any kind of electrical transient, current surge, and overloads. If a sudden surge of current is there, it will cause the wire in the drop out the fuse to melt. The transformer would thus be disconnected from the line and saves any damage to the transformer.

The drop out fuses which comes in polymer form is considered to be of excellent quality. Polymer drop out fuses are made using a good quality material which can survive the extreme and stressful environment. The silicone rubber which is used in the drop out fuse helps to overcome cold and extreme heating situations.

Major components of Dropout Fuses

The drop out fuse consists of three parts which are the cutout body, fuse holder, fuse element.

Cut out body: This is the frame which supports the fuse holder.

Fuse holder: This is the tube which contains the fuse element. The holder is well insulated and is also called as fuse tube. In the case of a surge in electricity, the fuse element would melt which will cause the fuse holder to break the circuit and will drop the contact on the upper side. The Fuse holder would be hanging from the hinge on the lower side. This helps the inspecting person to recognize a break in circuit immediately.

Fuse element: This is the element which is installed in the fuse holder that melts when there is a surge in electricity. This portion of the drop out fuse is replaceable, which will have to be done every time there is a break in the circuit.


The best part about the drop out fuse is that it does not require a high level of maintenance. The fuse element will have to be replaced every time there is a break in the circuit which is normal for every fuse. Other than that, the polymer drop out fuse requires very less maintenance on a regular basis. The installation of the drop out fuse is also very simple and can be done very easily. The design and the structure are very straight forward which makes it easy to install without any additional complications.

Prior to late 90’s the manufacturing of the fuse was done based on the standard defined by the respective manufacturing unit especially for the design of the fuse. Later, the fuse cut- outs were made for an interchangeable design which can be used for multiple cuts- out bodies.

When you are purchasing drop out fuses, make sure that the manufacturer has met the requirements as per the International Organization for Standardisation (ISO). The quality of the fuse should be ISO 9001 certified which is a guarantee for Quality Management System. It should also be ISO 14001 certified which talks about the Environmental Management System. Having the proper ISO certification in place will ensure that the drop out unit is manufactured under proper setup and is of good quality.