Fuses are used everywhere and everywhere - they are in technology, in a variety of electrical devices, cars, industrial equipment. There are many types of these elements. What are they for and what are their features? Consider the main types of fuses.
Characteristic
Fuse is a generic term that is used fairly consistently in the electrical field. This part provides protection for wires, equipment and electrical networks.
The fuse is a switching product. What is its purpose? The fuse is designed to protect the electrical network from high currents and short circuits. The principle of operation of the part is very simple - in the event of the formation of overcurrents, an element specially designed for this is destroyed. Often this is a fusible link. This is how all types of glass fuses are arranged.
These inserts are an indispensable element, without which no type of safety elements is possible. There is also a special arc extinguishing device inside it. Inserts infuses are made of porcelain or fiber cases and are fixed in special parts that conduct electricity. Elements designed for low currents may not have a case at all.
Fusible
These are the most common types of fuses for household use. This is probably the only element that is easiest to diagnose for serviceability. To do this, you just need to look at the part in the light - it will be clear whether the melting of the insert is intact or not.
These parts are made in a glass case.
Fusible Tubular Ceramic
This element is practically no different from a glass product. The only difference is in the material the case is made of. But in operation, these parts are not so comfortable - it will no longer be possible to diagnose “on the light”. To check, you must use testers or multimeters.
PVD fusible link
These types of fuses operate on the same principle.
But here the design is modified in such a way as to see the state of the part. So, if the element is burned out, then a special flag will appear at the back of the product.
Quartz Sand Elements
These fuses feature high arc-extinguishing characteristics. They are produced in two versions: in a case made of ceramic materials or in glass cases. Often the product is designed to work with high currents. There are moreimproved models. The fuse device provides for another part, similar in design to LDPE. It is necessary so that you can find out which fuse has blown.
Fast acting fuses
These products are nothing special from the rest. The only difference is that when a short circuit occurs, the fusible part burns out very quickly.
SMD
These products can be found in electronic devices. They are very tiny. The principle of operation and purpose of fuses is to protect equipment from high currents, with which they do an excellent job.
Self-healing
These are quite interesting solutions. A self-resetting fuse is a part with a special plastic inside. As long as the plastic insert is cold, it can conduct electricity. As soon as the insert warms up to a certain temperature, its conductive properties are lost due to an increase in resistance.
After cooling, the current will again be able to pass through the product. The advantage of these parts is that after a burnout there is no need to replace the element. The industry produces these products in various forms. They are suitable for surface mount or surface mount soldering. Basically, these types of fuses are used in low-power circuits.
Explosive
If everyone knows all of the above products, then the explosive fuse is a rare group. The process of burnout of the part is provided by a rather effectivesound. A special explosive device, which is attached to a conductive part, explodes. Special sensors are responsible for this. The latter monitor the current in the electrical circuit. These are very accurate fuses, as they are virtually independent of the characteristics of the metal on the conductive part. This item depends on the accuracy of the current sensor.
Other types of fuses
To work in high voltage circuits, special autogas, gas products, as well as liquid-type elements are used. There are even firing fuses. You cannot see them in everyday life - this is professional powerful equipment.
Markings and designations
Each manufacturer manufactures fuses under a specific code or part number. The fuse number allows you to find and clarify technical specifications in the catalogs. Often these codes can be found on the cases of products. Also, the code can be applied to the metal part. In addition to codes, basic data can also be indicated on the case - this is the rated current in A, rated voltages in V, tripping characteristics or design features. From this data, the purpose of the fuses can be determined.
So, the value of the rated current is the maximum allowable value at which the part can function normally for a long time.
Rated voltages are the maximum allowable voltage at which the part will safely break the circuit in the event of a short circuit or network overload.
The breaking capacity is called maximum currents. With them, the fuse will work, but its case will not be destroyed.
Characteristics are the dependence of the time at which the fusible element collapses on the current that flows through the part. Different types of fuses according to their characteristics are combined into groups according to the features of application and response speed.
Usually these characteristics are indicated on power parts. Letters of the Latin alphabet are used for designation. The first is the breaking capacity. So, G is the full range, the part is able to protect the circuit from both overload and short circuit. A - the range is partial, and these types of fuses protect only against short circuits.
The second letter indicates the chain types:
- G is a general purpose circuit.
- L - protection of cables as well as distribution systems.
- M - protection of circuits in electric motors.
- Tr is a fuse that can protect the transformer network.
Elements with the letter R are used in conjunction with power semiconductor equipment. And PV will be able to protect solar panels.
So, we have looked at what types of fuses are and what markings they have.
