What are the 3 types of fuses?

Types of thermal fuses

More than once you have heard about this protection element, but did you know that there is a type of fuse that has a time delay? In this blog we tell you about the different types of fuses and their differences, so that you can choose the right fuse for your installation or project.

There are automotive fuses, fuses for home protection equipment, ceramic fuses, glass fuses, cartridge fuses and the ones we will focus on here, the time-delay fuses or also known as slow blow fuses.

A definition of fuses would be the devices that are inserted in a determined point of an electrical installation so that they melt due to the Joule effect when a current intensity value is exceeded. This value is fixed in relation to the maximum value that can support the conductors of the installation without endangering the risk of fire or destruction of other elements. These high currents usually occur due to faults such as overloads or short circuits, so the malfunction will possibly affect the entire circuit and must be cut off.

Fuse types pdf

This type of fuse melts very quickly when the current is exceeded, although the response time of the fuse varies depending on the number of times it exceeds the current for which it is manufactured, taking into account that the fuse will not melt if the same current as the fuse is circulating through it.

Read more  Can you do microblading in Maryland?

In case the current is one and a half times higher than the rated current, the fuse will heat up and when working with this overcurrent it will blow, i.e. a fuse whose rated current is 2 amperes, in case 3 amperes circulate through the fuse, it will take one hour to blow.

When the current is four times the rated current, in the previous case where the fuse is 2 amperes, if 8 amperes circulate through the fuse, the fuse will blow in less than half a second (0.3 seconds).

The fast fuse is usually used in circuits that do not have a current increase at start-up and the circuit it protects is very sensitive to working with currents higher than the working currents.

What is the function of a fuse in an electrical circuit?

When current flows through a conductor, heat is generated due to the resistance offered by the material, this effect is called Joule’s law. The heat dissipated in the conductor depends on the geometrical characteristics and the type of material it is made of. The fuse is a simple sheet inserted in the circuit, which opens due to the heat generated in it. The amount of thermal energy generated by the current depends directly on the square of the current, the time of current circulation and the resistance of the conductor. The formula to calculate it is:

They are high interrupting capacity fuses or current limiters. The interrupting capacity of these fuses is between 10,000 and 200,000 A. These fuses have the ability to interrupt any current rating within their interrupting range, limiting peak current values.

Read more  Are there bass in the Trinity River?

They are current-limiting fuses with interrupting ratings of 10KA-RMS (rms) symmetrical. Their maximum operating voltage is 300V-AC. With rated currents up to 60A. They are non-replaceable, to be fixed in fuse holders.

What is a fuse?

In electricity, a fuse is a device consisting of a suitable support and a filament or sheet of a metal or low melting point alloy that is inserted at a certain point of an electrical installation so that it melts (by Joule effect) when the current exceeds (due to a short circuit or excess load) a certain value that could endanger the integrity of the conductors of the installation with the consequent risk of fire or destruction of other elements.

This concept is more easily understood when describing the current field of application, whose nominal parameters have very wide ranges. Operating voltages range from a few volts to 132 kV, rated currents from a few milliamps to 6 kA, and breaking capacities reach 200 kA in some cases.

Worldwide production statistics indicate the steady growth of the market. For some types of fuses the growth is very high, such as devices for low-power electronic circuits and elements for use in automobiles. On the other hand, traditional fuses (low and medium voltage, and high breaking capacity) are estimated to grow at a slower rate, in the order of the growth of electrical systems, at around 3% per year.

Read more  Does a spur Socket need to be fused?