Tact button designation on the diagram. Symbol in electrical diagrams

In order to correctly read and understand what a particular diagram or drawing related to electricity means, you need to know how the icons and symbols depicted on them are deciphered. A large amount of information is contained in the letter designations of elements in electrical circuits, defined by various regulatory documents. All of them are displayed in Latin characters in the form of one or two letters.

One-letter symbolism of elements

Letter codes corresponding to individual types of elements most widely used in electrical circuits are combined into groups designated by one symbol. Letter designations correspond to GOST 2.710-81. For example, the letter “A” refers to the “Device” group, consisting of lasers, amplifiers, remote control devices and others.

The group denoted by the symbol “B” is deciphered in the same way. It consists of devices that convert non-electrical quantities into electrical ones, which does not include generators and power supplies. This group is complemented by analogue or multi-digit converters, as well as sensors for indications or measurements. The components themselves included in the group are represented by microphones, loudspeakers, sound pickups, ionizing radiation detectors, thermoelectric sensitive elements, etc.

All letter designations corresponding to the most common elements are combined into a special table for ease of use:

In addition, GOST 2.710-81 defines special symbols to designate each element.

Conventional graphic symbols of electronic components in circuits

Before carrying out construction and installation work, a project is drawn up. Electrical installation work is no exception. In order for electrical circuits to be clear to all workers involved in installation and repair, the symbols of sockets, switches and other equipment are carried out according to a single standard.

Types of electrical circuits

The diagrams required to carry out the work have different types and purposes.

Structural and functional electrical diagrams

A block diagram is the simplest type of diagram. It conventionally depicts, most often in squares, the elements of a chain with explanatory inscriptions. This allows you to understand the principle of operation of the installation.

A functional electrical diagram differs from a structural diagram in a more detailed description of all elements and connections between them.

Schematic diagram

Such electrical circuits are used in distribution networks and control panels. They show all the elements in detail, without taking into account their relative positions. Such drawings allow you to understand the details of the operation of power supply lines and control circuits.

There are two types of circuit diagrams:

• Full. It shows all the elements and the wires connecting them. It can be expanded, depicting the entire electrical installation as a whole, and elemental, showing components and parts of the installation on separate sheets;
• Single-line. The drawing shows only power circuits. Such a diagram is called single-line because instead of several lines representing three phases, zero and grounding, only one is drawn.

Wiring diagram

Necessary for installation work. This equipment layout diagram shows the position of all fixtures, connecting wires, and other information needed to complete the electrical installation.

Integrated electrical circuit

Includes different types of wiring diagrams in one. This is done if it is possible to do this without cluttering the sheet with various elements and explanatory notes.

Reading Electrical Diagrams

It is necessary to understand the compiled electrical circuit: how it works, possible malfunctions and other nuances. This process is called "reading circuit diagrams." To do this, you need to know the conventional graphic symbols of all the parts depicted on it, as well as their connections.

Conductor designations

Wires connecting elements of electrical circuits are depicted as lines. They differ in explanatory inscriptions, numbers and, in some cases, thickness. In a single-line diagram, a thick line depicts a group of wires: phase and neutral or “plus” and “minus”.

In drawings with a large number of details, the conductors are not shown as a solid line, but at the beginning and end of the connection, with each wire marked and the connection location indicated. The wires going from one sheet to another are also shown.

Interesting. Connections of three or more wires are marked with a dot.

Hardware graphic symbols

In addition to wires, electrical circuits contain other equipment. All its types have their own conventional graphic images. They symbolically display the functions or design of devices. This is a schematic representation of circuit breakers, limit switches and lamps, made from simple geometric elements. Their combination carries all the information about the electrical appliance.

All symbols and their elements are indicated in special tables defined by GOST 21.614-88 “Conventional graphic images of electrical equipment and wiring on plans.” It is mandatory not only in production, but also when designing household electrical wiring.

Wiring diagram

Drawing up an electrical wiring diagram is necessary during the construction or major renovation of a house. This diagram is drawn up on a floor plan indicating the height of the cables and the installation locations of machines, sockets and switches.

This plan will be used not only by the person who compiled it, but also by installers, and subsequently by electricians who repair electrical wiring. Therefore, conventional images of sockets and switches in the drawings must be understandable to everyone and comply with GOST.

Designation of sockets on electrical diagrams

The symbol for a socket is a semicircle. The number and direction of lines extending from it show all the parameters of these devices:

• For hidden wiring, the semicircle is intersected by a vertical line. It is absent in devices for open wiring;
• In a single socket, one line goes up. In doubles there is a double dash;
• A single-pole socket is indicated by one line, a three-pole socket by three, diverging like a fan;
• Degree of protection from weather conditions. Devices with IP20 protection are depicted as a transparent semicircle, and with IP44-IP55 protection, this semicircle is painted black;
• The presence of grounding is indicated by a horizontal line. It is the same in devices of any configuration.

Interesting. In addition to electrical outlets, there are computer outlets (for the LAN cable), television outlets (for the antenna), and even vacuum outlets, to which the hose from the vacuum cleaner is connected.

Designation of switches on diagrams

The switches in all drawings look like a small circle with a line tilted to the right at the top. There are additional lines on it. By the number and type of these lines, you can determine the device parameters:

• a hook in the shape of the letter “G” is a device for open wiring, a transverse line in the shape of the letter “T” is for hidden wiring;
• line one - single-key switch, two - two-key, three - three-key;
• if the circle is filled in, then this is a device with a weather protection rating of IP44-IP55.

In addition to regular switches, there are pass-through and cross switches that allow you to control the light from several places. The designation of such devices in electrical circuits is similar to the usual ones, but there are two slashes: right-up and left-down. The symbols on them are duplicated.

For ease of use and a more aesthetic appearance, these devices are installed in adjacent mounting boxes and covered with a common lid. According to GOST, such blocks are designated by a semicircle, the lines on which correspond to each device individually.

The following figure shows two examples of switch and socket blocks:

• design for hidden wiring from a socket with a grounding contact and a double switch;
• design for hidden wiring from a socket with a grounding contact and two switches: double and single.

Symbols of other devices

In addition to sockets and switches, electrical wiring diagrams also use other elements that have their own symbols.

The designation of protection devices: circuit breakers, RCDs and voltage control relays is based on the image of an open contact.

The designation of a circuit breaker according to GOST consists of the required number of contacts connected to each other and a square on the side. This symbolizes the simultaneous operation of the protection system. Input circuit breakers in apartments are usually two-pole, and single-pole ones are used to disconnect individual loads.

There are no special designations according to GOST for RCDs and differential circuit breakers, so they reflect the design features. Such devices are a current transformer and an executive relay with contacts. In automatic machines, a circuit breaker for protection against overload and short circuit is added to them.

The voltage control relay turns off electrical appliances when the voltage deviates beyond acceptable limits. Such a device consists of an electronic board and a relay with contacts. This can be seen in the diagram of such devices. It is depicted on the top cover of the case.

Graphic symbols of lighting and illumination devices, including LED chandeliers, symbolize the appearance and purpose of the devices.

Knowledge of the symbols of sockets and switches and other equipment on the drawings is necessary when drawing up a project, installing and repairing electrical wiring and other electrical equipment.

Video

Conventional graphic symbols of switching products - switches, toggle switches, electrical relays are built on the basis of contact signs: making (Fig. 1, b), breaking (c, d) and switching (d, f). Contacts that immediately close or open two circuits are designated as shown in Fig. 1, (w, and And).

The initial position of the closing contacts on electronic circuits is taken to be the open state of the switched electronic circuit; the breaking contacts are the closed state; the switching contacts are the position in which one of the circuits is closed and the other is open (with the exception of the contact with the neutral position). The UGO of all contacts can only be depicted in a mirrored or rotated 90° position.

The standardized UGO system also provides for the reflection of such design features as the non-simultaneous operation of one or several contacts in a group, the absence or presence of their fixation in one of the positions.

Rice. 1

Rice. 2

So, if you need to show that the contact closes or opens earlier than others, the sign of its moving part is supplemented with a small stroke directed towards the operation (Fig. 2, a, b), and if later, with a stroke directed in the opposite direction (Fig. 2, c, d).

The absence of fixation in a closed or open position (self-return) is indicated by a small triangle, the top of which is oriented towards the initial position by the moving part of the contact (Fig. 2, e, f), and fixation is indicated by a circle on the sign of its fixed part (Fig. 2, g, And).

The last two UGOs on electronic circuits are used in cases where it is necessary to show a type of switching product whose contacts usually do not have these qualities.

The conventional graphic designation of switches on electronic circuits (Fig. 3) is based on the signs of making and breaking contacts. With all this, it is meant that the contacts are fixed in both positions, that is, they do not have self-return.

Rice. 3.

The letter code of products in this group is determined by the switched circuit and the design of the switch. If the latter is placed in the control, signaling, measurement circuit, it is designated by the letter S, and if in the power circuit - by the letter Q. The control method is reflected in the 2nd letter of the code: push-button switches and toggle switches are designated by the letter B (SB), automatic - letter F (SF), all others - letter A (SA).

If the switch has several contacts, the signs of their moving parts on the electronic circuits are placed in parallel and connected by a mechanical connection line. As an example in Fig. Figure 3 shows a conventional graphic designation of switch SA2, containing one break and two make contacts, and SA3, consisting of two make contacts, one of which (the right one in the figure) closes later than the other.

Switches Q1 and Q2 are used to switch power circuits. The Q2 contacts are mechanically connected to any control, as evidenced by the dashed strip. When depicting contacts in different sections of the circuit, their belonging to one switching product is usually reflected in an alphanumeric position designation (SA 4. 1, SA4.2, SA4.3).

Rice. 4.

Similarly, based on the sign of the switching contact, symbolic graphic symbols of two-position toggle switches are built on electrical circuits (Fig. 4, SA1, SA4). If the toggle switch is fixed not only in the latter, but also in the middle (neutral) position, the sign of the moving part of the contact will be placed between the signs of the fixed parts, the possibility of turning it in both directions is demonstrated by a dot (SA2 in Fig. 4). The same is done in this case, if you need to show on the diagram a toggle switch that is fixed exclusively in the middle position (see Fig. 4, SA3).

A distinctive feature of UGO push-button switches and toggle switches is the button sign connected to the designation of the moving part of the contact by a mechanical connection line (Fig. 5). With all this, if the conventional graphic designation is built on the basis of the main contact sign (see Fig. 1), then this means that the switch (toggle switch) is not fixed in the pressed position (when the button is released, it returns to the initial position).

Rice. 5.

If you need to show fixation, use signs of contacts with fixation specially created for this purpose (Fig. 6). Return to the initial position when pressing another toggle switch button is demonstrated in this case by the symbol of the locking mechanism, attaching it to the symbol of the moving part of the contact on the side opposite to the button symbol (see Fig. 6, SB1.1, SB 1.2). If the return occurs when the button is pressed again, the symbol of the locking mechanism is depicted instead of the mechanical link strip (SB2).

Multi-position toggle switches (for example, biscuits) are designated as shown in Fig. 7. Here SA1 (for 6 positions and 1 direction) and SA2 (for 4 positions and 2 directions) are toggle switches with leads from moving contacts, SA3 (for 3 positions and 3 directions) - without leads from them. The conventional graphic designation of individual contact groups is depicted on the diagrams in a similar position; belonging to one toggle switch is usually demonstrated in the positional designation (see Fig. 7, SA1.1, SA1.2).

Rice. 7.

To depict multi-position toggle switches with complex switching, GOST provides several methods. Two of them are shown in Fig. 8. Toggle switch SA1 - 5 positions (they are indicated by numbers; letters a-d are included for clarification only). In position 1, chains a and b, d and d are connected to each other, in positions 2, 3, 4 - chains b and d, a and c, a and d, respectively, in position 5 - chains a and b, c and d .

Toggle switch SA2 - 4 positions. In the first of them, chains a and b are closed (this is indicated by the points located under them), in the 2nd - chains c and d, in the 3rd - c and d, in the fourth - b and d.

Zorin A. Yu.

Electrician school

Electronic drawings and diagrams

If you are engaged in electrical installation work, then you definitely need to know the symbols in electrical circuits. The ability to read electrical diagrams is an important quality for fitters, instrumentation mechanics, and circuit designers. And if you do not have special training, it is unlikely that you will be able to immediately understand all the intricacies. But we must remember that the symbols on the diagrams that are being developed for Russian consumers differ from generally accepted standards abroad - in Europe, the USA, and Japan.

History of designations on diagrams

Back in the Soviet years, when electrical engineering was developing rapidly, the need arose to classify devices and their designation. It was then that the Unified System of Design Documentation (ESKD) and state standards (GOST) appeared. Everything was standardized so that any engineer could read the symbols on the drawings of his colleagues.

But in order to understand all the intricacies, you will need to listen to many lectures and study a lot of specialized literature. GOST is a huge document, and it is almost impossible to fully study all the graphic symbols and their standard sizes and notes. Therefore, it is necessary to always have a small “cheat sheet” on hand that will help you navigate the variety of electrical components.

Electrical wiring on drawings

Electrical wiring is a general concept; it refers to conductors that have very low resistance. With their help, voltage is transmitted from the source of electricity to consumers. This is a general concept as there are many types of electrical wiring.

People who do not understand electrical wiring diagrams and features may think that a conductor is an insulated cable that connects to switches and sockets. But in fact, there are many types of conductors, and they are designated differently on diagrams.

Conductors on diagrams

Even copper tracks on PCB circuit boards are a conductor; one might even say that this is a variant of electrical wiring. Indicated on electrical diagrams as a straight connecting line passing from one element to another. In the same way, the electrical wires of a high-voltage line laid in the fields between the poles are indicated on the diagram. And in apartments, the connecting wires between lamps, switches and sockets are also indicated by straight connecting lines.

But the designations of conductive elements can be divided into three subgroups:

1. Wires.
2. Cables.
3. Electrical connections.

Electrical wiring plan is an incorrect definition, since electrical wiring refers to both installation wires and cables. But if you significantly expand the list of elements, as is necessary in the detailed diagram, it turns out that it is necessary to include also transformers, circuit breakers, residual current devices, grounding, and insulators.

Sockets on diagrams

Sockets are plug connections designed for non-rigid connection (there is the possibility of manually breaking the connection) of electrical circuits. Symbols on the drawings are strictly regulated by GOST. With its help, rules are established for designating lighting devices and devices and various other electrical consumers on drawings. Plug-type sockets can be divided into three categories:

1. Designed for outdoor installation.
2. Designed for hidden installation.
3. A block that includes a socket and a switch.

1. Single pole sockets.
2. Bipolar.
3. Bipolar and safety contact.
4. Three-pole.
5. Three-pole and protective contact.

That's enough, the sockets have no special features, there are many design options. All devices have a degree of protection; the choice must be made based on the conditions in which they will be used: humidity level, temperature, presence of mechanical stress.

Switches on wiring diagrams

Switches are devices that break an electrical circuit. This can be done automatically or manually. The conventional graphic designation is regulated by GOST, as with sockets. The designation depends on the conditions in which the element operates, what design it has, and the degree of protection. There are several types of switch designs:

1. Single-pole (including double and triple).
2. Bipolar.
3. Three-pole.

The diagrams must indicate the parameters of the disconnecting device. And the graphic designation shows which type is used: simple with or without fixation, an acoustic device (responsive to cotton) or an optical one. If you want the lights to turn on at nightfall and turn off in the morning, you can use an optical sensor and a small control circuit.

Fuses (fuse links)

There are many types of protection devices - fuses (disposable and self-restoring). Many types of design, scope of application, different response speeds, reliability, use in certain conditions characterize these devices. The symbol for a fuse is a rectangle; the simplest and cheapest element that can protect an electrical circuit from a short circuit runs parallel to the long side through the center. It should be noted that such components are quite rarely used in electrical circuit diagrams. Another type of symbol can be found - these are self-resetting fuses, which, after opening the circuit, return to their original state.

The broad name for fuses is fuse link. It is used in many devices, in electrical distribution panels. You can find them in disposable corks. But there are also devices used in high-voltage systems. They are structurally made of metal tips and a main ceramic part. Inside there is a piece of conductor (its cross-section is selected depending on the maximum current that should flow through the circuit). The ceramic body is filled with sand to prevent the possibility of ignition.

Circuit breakers

The symbols for devices of this type depend on the design and degree of protection. The reusable device can be used as a simple switch. In essence, it performs the functions of a fuse-link, but it is possible to return it to its original state - to close the circuit. The structure consists of the following elements:

1. Plastic case.
2. Lever for turning on and off.
3. Bimetallic plate - when heated, it deforms.
4. Contact group - it is included in the electrical circuit.
5. Arc chamber - allows you to get rid of the formation of sparks and arcs during a connection break.

These are the elements that make up any circuit breaker. But you need to remember that after triggering it will not be able to immediately return to its original position; time must pass for it to cool down. The service life of machines is measured in the number of operations and ranges from 30,000-60,000.

Grounding on diagrams

Grounding is the connection of the current conductors of an electric machine or device to the ground. In this case, both the ground and part of the device circuit have a negative potential. Thanks to grounding, if the case breaks down, there will be no damage to the device or electric shock; the entire charge will go into the ground. Grounding is of the following types according to GOST:

1. General concept of grounding.
2. Pure grounding (noise-free).
3. Protective type of grounding.
4. Connection to the ground (body) of the device.

Depending on which grounding is used in the circuit, the symbol will be different. When drawing up diagrams, the drawing of the element plays an important role; it depends both on the specific section of the circuit and on the type of device.

If we are talking about automotive equipment, then there will be a “ground” - a common conductor connected to the body. In the case of home electrical wiring, these are conductors driven into the ground and connected to outlets. In logic circuits, one should not confuse “digital” grounding and conventional one - these are different things and they work differently.

Electric motors

Electric motors can often be found on electrical circuit diagrams of cars, workshops, and devices. Moreover, in industry, more than 95% of all motors used are asynchronous with a squirrel-cage rotor. They are designated in the form of a circle, to which three wires (phases) fit. Such electric machines are used in conjunction with buttons (“Start”, “Stop”, “Reverse” if necessary).

DC motors are used in automotive technology and control systems. They have two windings - working and excitation. Instead of the latter, permanent magnets are used on some types of motors. A magnetic field is created using the excitation winding. It pushes the motor rotor, which has a counter-directional field - it is created by the winding.

Wire color coding

In the case of single-phase power, the conductor with the phase is black, gray, purple, pink, red, orange, turquoise, white. Most often you can find brown. This marking is generally accepted and is used when drawing up diagrams and installation. is marked:

1. Blue color - zero worker (N).
2. Yellow with a green stripe - grounding, protection (PE) wire.
3. Yellow with green and blue marks on the edges - the protective and neutral conductors are combined.

It should be noted that blue marks must be applied during installation. The symbol in electrical diagrams must also have a reference to the presence of marks. The conductor must be marked with the index PEN.

According to their functional purpose, all conductors are divided as follows:

1. Black wires - for switching power circuits.
2. Red wires - for connections of control, measurement, alarm elements.
3. Blue conductors - control, measurement and signaling when operating on direct current.
4. Zero working conductors are marked in blue.
5. Yellow and green are wires for grounding and protection.

Alphanumeric designations on diagrams

The terminals have the following symbols in electrical diagrams:

• U, V, W - wiring phases;
• N - neutral conductor;
• E - grounding;
• PE - protective circuit wire;
• TE - conductor for silent connection;
• MM - conductor connected to the body (ground);
• CC - equipotential conductor.

Designation on wire diagrams:

• L - letter designation (general) of any phase;
• L1, L2, L3 - 1st, 2nd and 3rd phases, respectively;
• N - neutral wire.

In DC circuits:

• L+ and L- - positive and negative poles;
• M - middle conductor.

These are the symbols most often used in diagrams and drawings. They can be found in descriptions of simple devices. If you need to read the diagram of a complex device, you will need a lot of knowledge. After all, there are also active elements, passive elements, logic devices, semiconductor components and many others. And each has its own designation on the diagrams.

UGO winding elements

There are many devices that convert electrical current. These are inductor coils. The symbol of a transformer in the diagrams is two coils (depicted as three semicircles) and a core (usually in the form of a straight line). A straight line indicates a transformer steel core. But there may be transformer designs that do not have a core, in which case there is nothing on the diagram between the coils. This symbolic designation of elements can also be found in circuits of radio receiving equipment, for example.

In recent years, transformer steel has been used less and less in technology for the manufacture of transformers. It is very heavy, it is difficult to insert the plates into the core, and there is a buzzing sound when loosened. The use of ferromagnetic cores is much more effective. They are solid and have the same permeability in all areas. But they have one drawback - the difficulty of repair, since disassembling and reassembling turns out to be problematic. The symbol for a transformer with such a core is practically no different from the one in which steel is used.

Conclusion

These are not all the symbols of electrical circuits; the dimensions of the components are also regulated by GOST. Even simple arrows and connection points have requirements; their drawing is carried out strictly according to the rules. You need to pay attention to one feature - the differences in circuits made according to domestic standards and imported ones. The intersection of conductors on foreign diagrams is indicated by a semicircle. There is also such a thing as a sketch - this is an image of something without complying with GOST requirements for elements. Separate requirements apply to the sketch itself. Such images can be made to visually represent the future design and electrical wiring. Subsequently, a drawing is drawn up from it, in which even the symbols of conventional cables and connections comply with the standards.

] - switches, switches and electromagnetic relays are built on the basis of contact symbols: normally open ( rice. 5.1, b), opening (c, d) and switching (d, f). Contacts that simultaneously make or break two circuits are designated as shown in rice. 5.1, f, i.

The initial position of the closing contacts is taken to be the open state of the switched electrical circuit, the breaking contacts are taken to be closed, and the switching contacts are taken to be the position in which one of the circuits is closed and the other is open (with the exception of the contact with the neutral position). The UGO of all contacts can only be depicted in a mirrored or rotated 90° position.

The standardized UGO system also provides for the reflection of such design features as the non-simultaneous operation of one or more contacts in a group, the absence or presence of their fixation in one of the positions. So, if it is necessary to show that the contact closes or opens earlier than others, the symbol of its moving part is supplemented with a short stroke directed towards the operation ( rice. 5.2, a, b), and if later, with a stroke directed in the opposite direction ( rice. 5.2, c, d). The absence of fixation in the closed or open positions (self-return) is indicated by a small triangle, the apex of which is directed towards the initial position of the moving part of the contact (Fig. 5.2, e, c), and fixation is indicated by a circle on the symbol of its fixed part ( rice. 5.2, f, i). The last two UGOs are used in cases where it is necessary to show a type of switching product whose contacts usually do not possess these properties.
Conventional graphic designation of switches ( rice. 5.3) are built on the basis of the symbols of normally open and closed contacts. This means that the contacts are fixed in both positions, i.e., they do not have self-return.

The letter code of products in this group is determined by the switched circuit and the design of the switch. If the latter is placed in the control, signaling, measurement circuit, it is designated by the Latin letter S, and if in the power circuit - by the letter Q. The control method is reflected in the second letter of the code: push-button switches and switches are designated by the letter B (SB), automatic ones - by the letter F (SF), all others - with the letter A (SA).

If the switch has several contacts, the symbols of their moving parts are placed in parallel and connected by a mechanical connection line. As an example on rice. 5.3 shows a conventional graphic designation of switch SA2, containing one break and two make contacts, and SA3, consisting of two make contacts, one of which (right in the figure) closes later than the other. Switches Q1 and Q2 are used to switch power circuits. The Q2 contacts are mechanically connected to some control, as indicated by the dashed line segment. When depicting contacts in different sections of the circuit, their belonging to the same switching product is traditionally reflected in an alphanumeric positional designation (SA4.1, SA4.2, SA4.3).

Similarly, based on the symbol of the switching contact, graphic symbols of two-position switches are built ( rice. 5.4, SA1, SA4). If the switch is fixed not only in the extreme, but also in the middle (neutral) position, the symbol of the moving part of the contact will be placed between the symbols of the fixed parts, the possibility of turning it in both directions is shown by a dot (SA2 on rice. 5.4). The same is done if it is necessary to show on the diagram a switch that is fixed only in the middle position (see Fig. rice. 5.4, SA3).

A distinctive feature of UGO push-button switches and switches is the button symbol connected to the designation of the moving part of the contact by a mechanical connection line ( rice. 5.5). Moreover, if the conventional graphic symbol is built on the basis of the main contact symbol (see. rice. 5.1), this means that the switch (switch) is not fixed in the pressed position (when the button is released, it returns to its original position). If it is necessary to show fixation, use symbols of contacts with fixation specially designed for this purpose ( rice. 5.6). Return to the original position when pressing another switch button is shown in this case by the symbol of the locking mechanism, attaching it to the symbol of the moving part of the contact on the side opposite to the button symbol (see Fig. 5.6, 5B1.1, SB12). If the return occurs when the button is pressed again, the sign of the locking mechanism is depicted instead of the mechanical connection line (SB2).
Multi-position switches (for example, biscuits) are designated as shown in rice. 5.7. Here SA1 (for 6 positions and 1 direction) and SA2 (for 4 positions and 2 directions) are switches with leads from moving contacts, SA3 (for 3 positions and 3 directions) - without leads from them. The conventional graphic designation of individual contact groups is depicted in the same position on the diagrams; belonging to one switch is traditionally shown in the position designation (see. rice. 5.7, SA1.1, SA1.2).

To depict multi-position switches with complex switching, GOST provides several methods. Two of them are shown in Fig. 5.8 . Switch SA1 has 5 positions (they are indicated by numbers; letters a-e are entered for clarification only). In position 1, chains a and b, d and d are connected to each other, in positions 2, 3, 4 - chains b and d, a and c, a and d, respectively, in position 5 - chains a and b, c and d .

Switch SA2 - 4 positions. In the first of them, chains a and b are closed (this is indicated by the dots located under them), in the second - chains e and d, in the third - c and d, in the fourth - b and d.