Fuses are used everywhere and everywhere - they are in engineering, in a variety of electrical devices, automobiles, industrial equipment. There are many types of these elements. Why are they needed and what are their features? Consider the main types of fuses.
Characteristic
A fuse is a general term that is used fairly steadily in the field of electrics. This part provides protection for wires, equipment and electrical networks.
A fuse is a switching product. What is his 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, the specially designed element is destroyed. This is often a fuse. This is the way all types of glass fuses work.
These inserts are an indispensable element, without which no kind of safety elements is possible. Inside it there is also a special arcing device. The inserts in the fuses are made of porcelain or fiber housings and are fixed in special parts that conduct electric current. Elements designed for low currents may not have a housing at all.
Melting
These are the most common types of fuses for domestic use. This is probably the only element that is easiest to diagnose for health. To do this, you just need to look at the detail in the light - it will be seen whether the insert is melted 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 the material of which the body is made. But in operation, these parts are not so comfortable - to diagnose "in the light" will not work. To check it is necessary to use testers or multimeters.
LDPE fusible insert
These types of fuses operate on the basis of the same principle.
But here the design is modified in such a way as to see the condition of the part. So, if an element burns out, a special flag will appear in the back of the product.
Quartz sand elements
These fuses are characterized by high arc suppression 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 also more advanced models. The fuse device provides another part, similar in design to LDPE. It is necessary so that you can find out which of the fuses has blown.
High speed fuses
These products are no different 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 the fuses is to protect the equipment from high currents, which they can do perfectly.
Self-healing
These are quite interesting solutions. A self-resetting fuse is a part inside which is a special plastic. While the plastic insert is cold, it can conduct electricity. As soon as the insert is heated to a certain temperature, its conductive properties are lost due to an increase in resistance.
After cooling, the current can again pass through the product. The advantage of these parts is that after burnout, there is no need to replace the element. The industry produces these products in various forms. They are suitable for soldering using surface mounted or surface mount technology. Basically, these types of fuses are used in low-power circuits.
Explosive
If everyone knows all of the above products, then an explosive fuse is a rare group. The process of burning parts provides a fairly spectacular sound. A special explosive device that is mounted on a conductive part explodes. Special sensors are responsible for this. The latter monitor the current in the electrical circuit. These are very accurate fuses, since they are practically 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 and gas products are used, as well as liquid-type elements. There are even shooting fuses. You cannot see them in everyday life - this is professional powerful equipment.
Marking and designations
Each manufacturer makes fuses under a certain code or article. The fuse number allows you to find and specify technical specifications in the catalogs. Often these codes can be found on product housings. Also, the code can be applied to the metal part. In addition to codes, the main data can also be indicated on the case - this is the rated current in A, rated voltages in V, breaking characteristics or design features. From these data, you can determine the purpose of the fuses.
So, the value of the rated current is the maximum permissible value at which the part can function normally for a long time.
Rated voltage is the maximum allowable voltage at which the part safely breaks the circuit in the event of a short circuit or during overload in the network.
The breaking capacity is called the maximum currents. With them, the fuse will blow, but its housing will not be destroyed.
The characteristics are called the time dependence 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 their application and tripping speed.
Typically, these characteristics indicate power parts. For designation, letters of the Latin alphabet are used. 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 is a partial range, and these types of fuses protect only against short circuits.
The second letter denotes the types of circuit:
- G is a general purpose circuit.
- L - protection of cables and distribution systems.
- M - circuit protection 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 examined what types of fuses are and what they are labeled.