Symbols in electrical circuits: relay, fuse and other circuit elements

Everyone involved in electrical work needs to know the symbols in electrical circuits. The ability to read them will come in handy for electricians, designers and instrumentation fitters. Without special initial training, it will be quite difficult to understand all the intricacies of this issue. It should also be noted that the symbols of electrical circuit elements in Russia and abroad are different.

Letter symbols for electrical components

The elements of the electrical circuit have not only graphic, but also letter designation. They contain a lot of information, and every specialist should understand this issue.

Groups of elements are usually denoted by one Latin letter:

• B - microphones, loudspeakers, pickups, etc.
• K - designation of the relay in the diagram, as well as contactors.
• C - capacitors of various capacities.
• M - engines.

These are just a few groups of elements of electrical circuits.

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, and their full list can be found in the corresponding GOST. To get an accurate idea of ​​the element used in a particular case, letter designations on electrical diagrams are used, consisting of two letters.

As an example, we can give several characters from group B:

• VA - loudspeakers.
• BL - photocells.
• VK - heat sensors.

Graphic symbols

To memorize all the elements of the electrical circuit and their symbols, it is necessary to study GOST, which is a voluminous document. But even in such a situation, it is almost impossible to remember everything. To quickly read the wiring diagram if necessary, you should always have a cheat sheet on hand. You should start studying the designations of elements on electrical circuits with the most common ones, for example, those used in electrical wiring.

Use conductors and ground as an example. The first group of elements includes not only wires and cables, but also electrical connections, for example, paths of printed circuit boards. Grounding - connecting the conductors of electrical appliances and machines to the ground. As a result, in case of a breakdown of the case, a person will not suffer from an electric current. Since there are several types of grounding, each of them has its own graphic symbol.

Outlet designation

This element of the electrical circuit is plug connection, with the ability to manually disconnect the connection. The symbols used to indicate the outlets are strictly regulated by GOST. In this case, the sockets can be divided into several groups:

• For surface mounting.
• For hidden installation.
• A device that combines a switch and an outlet.

Moreover, in each of these groups there is an additional division depending on the availability of protection and the method of connection:

• Single pole.
• Bipolar with and without protective contact.
• Three-pole with and without protection.

Conventional switch symbols

The switches can be used to quickly break the electrical connection. This can happen in manual or automatic mode. As in the case of outlets, the conventional symbols of the switches are regulated. According to their design, there are several types of these devices. The electrical diagram must indicate the parameters of the switches. Graphic symbols can tell at a glance which type of device is used in each specific case: conventional, optical, acoustic, etc.

Fuses and circuit breakers

A large number of protective devices are in use today. All of them differ in design, scope and technical characteristics. However, there is a general designation for a fuse in the diagram - a rectangle through the center of which a conductor runs parallel to the long side. This symbol is used to indicate the cheapest circuit elements designed to protect it from short circuits.

Circuit breakers are designated according to their design and degree of protection. They act as fusible links, but can be returned to their original position to close the circuit. An excellent example of such a device is an automatic plug, widely used in everyday life and installed in electricity meters.

Electric motors

This element is often found on electrical circuits.. In industry, most motors are asynchronous squirrel-cage motors. At the moment, DC motors are also widely used. It is quite obvious that each type of these devices is indicated on the diagram in a certain way.

Today, radio electronics is developing rapidly, and specialists need to know the conventional graphic signs of various radio elements. It should be remembered that strict requirements are imposed on all designations on the diagrams, and in order to become familiar with them, it is necessary to study GOST.