Designation of electric wires on the diagrams. Overview of conventional graphic symbols used in electrical circuits. UGO in single-line and complete electrical circuits

GOST 2.709-89

Group T52

INTERSTATE STANDARD

one system design documentation

DESIGNATIONS CONDITIONAL WIRES AND CONTACT CONNECTIONS OF ELECTRIC ELEMENTS, EQUIPMENT AND CIRCUIT SECTIONS IN ELECTRICAL CIRCUITS

Unified system of design documentation. Conventions of wires and terminal connections of electrical elements, equipment and subcircuits in circuit diagrams

MKS 01.080.40
31.180
OKSTU 0002

Introduction date 1990-01-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR State Committee for Standards

DEVELOPERS

S.S. Borushek; V.V. Gugnina; B.Ya.Kabakov; B.S. Mendrikov; S.L. Taller; N.K.Tokareva; P.A. Shalaev, Ph.D. tech. Sciences

2. APPROVED AND INTRODUCED BY Decree State Committee USSR according to the standards of 03.24.89 N 669

3. The standard fully complies with ST SEV 3754-72, ST SEV 6308-88

4. REPLACE GOST 2.709-72

5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

6. REPUBLICATION. November 2007


This standard applies to electrical diagrams of products in all industries and construction and establishes symbols for wires and clamps electrical elements, devices, equipment, basic electrical elements (resistors, fuses, relays, transformers, rotating machines), motor control devices, power supply, grounding, connection to the housing, circuit sections in electrical diagrams.

1. GENERAL PROVISIONS

1. GENERAL PROVISIONS

1.1. This International Standard specifies the methods used to distinguish terminals, and general rules for their uniform designation.

Note. The term "terminal designation" is used to designate conductive sections of the circuit and electrical elements intended for connection.

1.2. A single designation method can be used when using computer technology and transmitting information by teletype.

1.3. The drawings in this standard are given as examples to clarify the text.

2. METHODS OF DESIGNATION

2.1. To select the terminal designation method important criterion is their function and location.

The distinguishing features of the designation method are:

1) the location of the clamps according to the chosen system;

2) conditional color according to the chosen system;

3) conventional graphic designation according to GOST 2.721;

4) alphanumeric designation according to Section 4.

Note. These methods are equivalent in terms of their use.

It is allowed to use graphic symbols in accordance with GOST 2.721 instead of alphanumeric ones (see tables 1 and 2).

2.2. The choice of marking method depends on the type of device, the location of the terminals, and the complexity of the device or wiring.

2.3. Alphanumeric designations are used for complex devices and wiring and are convenient for teletype transmission.

3. USE OF NOTATION

3.1. To designate the clamps of electrical elements, a conditional color is used, the corresponding graphic or alphanumeric designation.

3.2. When marking terminals with a conditional color, the relationship of the color and the equivalent graphic or alphanumeric designation must be shown in the accompanying documentation.

3.3. If the design of a particular element or device does not allow the designation of the clamp, then the accompanying documentation must show the relationship between the location of the clamp, equivalent graphical or alphanumeric designations, and mutual arrangement clamps.

4. UNIFIED SYSTEM OF LETTER-NUMERIC DESIGNATIONS OF WIRES AND CLAMPS

4.1. When constructing alphanumeric designations, capital letters of the Latin alphabet and Arabic numerals are used.

Letters I and O are not recommended.

4.2. The full designation consists of groups, each group - of letters and (or) numbers.

It is allowed to omit one or more groups, if this does not lead to an error during connections.

A period is used to separate groups consisting only of numbers or letters. If there is no need to distinguish subsequent groups, the dot can be omitted. For example, the full designation 1U11 can be written as follows: 1.11, if there is no need to indicate the group U; if there is no need to distinguish subsequent groups, the dot can be omitted: 111.

4.3. It is allowed to use the signs "+" and "-" when transmitting by teletype.

Notation principles

4.4. The designation system follows the following principles.

The two end points of the elements are designated by consecutive numbers (for example, 1 and 2 in Figure 1).

intermediate points simple element denoted preferably by subsequent digits (3, 4, 5, etc.).

The numbering of intermediate points starts from the end point indicated by the lower number. For example, the intermediate points of the element with end clamps 1 and 2 are indicated by the numbers 3, 4, 5 according to drawing 2.

4.5. When several identical elements are combined into groups, the ends of these elements are indicated in the following way:

1) letters (for example, U, V, W) are placed before the numbers according to clause 4.4 in accordance with the phases of the three-phase system (Fig. 3a);

2) in front of the numbers according to clause 4.4, if there is no need or possibility of phase discrimination, the next number is placed. For example, the ends of one element are marked 1.1 and 1.2, and the same ends of the next element - 2.1 and 2.2, if this does not lead to a change in the designation 11, 12 and 21, 22 (Fig. 3b).

4.6. Identical groups of elements, the ends of which within these groups are assigned designations in accordance with clause 4.5, are distinguished by placing the serial numbers of the groups in front of these designations according to drawing 4.

Clamp code for elements direct current it is preferable to choose from the first half of the Latin alphabet, and for elements alternating current- from the second half of the alphabet.

Note. An example of the use of alphanumeric designations of wires and clamps of a three-phase system is shown in Figure 5.

Terminal designations electrical devices attached to special wires are given in Table 1.

Table 1

Terminals of electrical devices designed for direct or indirect connection to the supply wires of a three-phase system are preferably marked with the letters U, V, W, if the phase sequence must be observed.

The clamp connected to the body is designated by the letters MM, the equipotential clamp is CC. This designation is used only when the connection of this terminal to the protective conductor or earth is not visible.

4.7. Wire designations special kind are given in Table 2.

table 2

5. DESIGNATION OF CIRCUIT PARTS

5.1. The designation of circuit sections serves to identify them, can reflect their functional purpose and creates a connection between the circuit and the device.

5.2. When designating, capital letters of the Latin alphabet and Arabic numerals are used, made in the same font size.

5.3. Sections of the circuit separated by contacts of devices, windings of machines, resistors and other elements must have a different designation.

5.4. Connections passing through non-separable, collapsible and detachable contact connections are designated the same. In justified cases, different designations are allowed.

5.5. Circuit sections in the circuit are designated regardless of the numbering of the input and output terminals of machines and devices.

5.6. The designation sequence should be, as a rule, from the input (power supply) to the consumer. Branching chains are designated from top to bottom in the direction from left to right.

For convenient orientation in the diagrams, when designating sections of circuits, it is allowed to leave reserve numbers or skip some numbers.

5.7. The designation of the alternating current circuit consists of the designation of sections of the phase circuits and a sequential number.

An example of the designation is shown in Fig.6. It is allowed to abbreviate the designation according to clause 4.2.

It is allowed, if this does not cause an erroneous connection, to designate the phases, respectively, with the letters A, B, C.

5.8. To distinguish phase or polarity wires related to different consumers, sequential numbers are used, which are placed before the designation of this phase or polarity (for example, the designation 2L1 means the wire of the first phase leading to the second consumer).

5.9. It is allowed to designate sections of the chain with consecutive numbers, as indicated in Fig. 7.

5.10. DC circuits are denoted by odd numbers in the areas of positive polarity and even numbers in the areas negative polarity. The input and output sections of the circuit are designated with the indication of the polarity "L +" and "L-"; it is allowed to use only the signs "+" and "-" (Fig. 8).

5.11. It is allowed to include the designation of phases in the designation of control, protection, signaling, automation, measurement circuits (Fig. 9).

In single-phase and two-phase non-power AC circuits, it is allowed to designate sections of circuits with even and odd numbers.

It is allowed to include in the circuit designation a designation characterizing the functional purpose of the circuit. In this case, the sequence of numbers is allowed to be set within the functional chain.

5.12. It is allowed to include in the designation of the circuits of a separate device included in the product, an uppercase letter of the Latin alphabet (except for A, B, C, M), chosen to designate the circuits this device. In this case, the sequence of numbers is allowed to be set within the device.

5.13. On the diagram, the designation is put down near the ends or in the middle of the chain section: to the left of the chain image - with a vertical arrangement of the chain; above the image of the chain - with a horizontal arrangement of the chain.

In technically justified cases, it is allowed to affix designations above the circuit image.

5.14. As a designation, the addresses of the connections of the circuit section can be used. In this case, at the beginning of the section, the address of the connection of the end of the section is indicated, and at the end, the address of the connection of the beginning of the section. As addresses, alphanumeric designations of the element, device or functional group according to GOST 2.710 (drawings 10 and 11).

It is allowed to use a mixed designation, consisting of an indication of the circuit and connection addresses (Fig. 12).

Electronic text of the document
prepared by CJSC "Kodeks" and checked against:
official publication
Unified design system
documentation: Sat. GOSTs. -
M.: Standartinform, 2008

Wiring diagram- this is a text that describes the content and operation of an electrical device or a set of devices with certain symbols, which allows short form express this text.

In order to read any text, you need to know the alphabet and reading rules. So, to read the schemes, you should know the symbols - symbols and the rules for decoding their combinations.

The basis of any electrical circuit is conventional graphic symbols various elements and devices, as well as the connections between them. The language of modern diagrams emphasizes in symbols the main functions that the depicted element performs in the diagram. All correct conventional graphic designations of electrical circuit elements and their separate parts are given in the form of tables in the standards.

Conditional graphic symbols are formed from simple geometric shapes: squares, rectangles, circles, as well as from solid and dashed lines and points. Their combination according to a special system, which is provided by the standard, makes it possible to easily depict everything that is required: various electrical apparatus, appliances, electric cars, lines of mechanical and electrical connections, types of winding connections, type of current, nature and methods of regulation, etc.

In addition, special signs are additionally used in the conventional graphic symbols on electrical circuit diagrams to explain the features of the operation of one or another element of the circuit.

So, for example, there are three types of contacts - closing, opening and switching. The symbols reflect only the main function of the contact - closing and opening the circuit. To specify additional functionality For a particular contact, the standard provides for the use of special characters applied to the image of the moving part of the contact. Additional signs allow you to find contacts, time relays, limit switches, etc. on the diagram.

Individual elements on electrical diagrams have not one, but several designations on the diagrams. For example, there are several equivalent designations for changeover contacts, as well as several standard designations for transformer windings. Each of the designations can be used in certain cases.

If the standard does not contain the necessary designation, then it is compiled based on the principle of operation of the element, designations adopted for similar types of apparatus, instruments, machines in compliance with the construction principles stipulated by the standard.

Standards. Conventional graphic symbols on electrical and automation diagrams:

GOST 2.710-81 Alphanumeric designations in electrical circuits:

The ability to read wiring diagrams is an important component, without which it is impossible to become a specialist in the field of electrical work. Every novice electrician must know how sockets, switches, switching devices and even an electricity meter are indicated on the electrical wiring project in accordance with GOST. Next, we will provide readers of the site with symbols in electrical circuits, both graphic and alphabetic.

Graphic

As for the graphic designation of all the elements used in the diagram, we will provide this overview in the form of tables in which the products will be grouped according to their purpose.

In the first table you can see how electrical boxes, boards, cabinets and panels are marked on the wiring diagrams:

The next thing you should know is the symbol for power sockets and switches (including walk-throughs) on single-line diagrams of apartments and private houses:

As for lighting elements, fixtures and lamps according to GOST are indicated as follows:

In more complex schemes where electric motors are used, elements such as:

It is also useful to know how transformers and chokes are graphically indicated on circuit diagrams:

Electrical measuring instruments according to GOST have the following graphic designation in the drawings:

And here, by the way, is a table useful for beginner electricians, which shows how the ground loop looks on the wiring plan, as well as the power line itself:

In addition, on the diagrams you can see a wavy or straight line, “+” and “-”, which indicate the type of current, voltage and pulse shape:

In more complex automation schemes, you may encounter obscure graphic symbols, such as contact connections. Remember how these devices are indicated on the wiring diagrams:

In addition, you should be aware of how radio elements look on projects (diodes, resistors, transistors, etc.):

That's all conditionally graphic designations in electrical circuits of power circuits and lighting. As you yourself have already seen, there are quite a lot of components and you can remember how each is designated only with experience. Therefore, we recommend that you save all these tables for yourself, so that when reading the project for the wiring of a house or apartment, you can immediately determine what kind of circuit element is in a certain place.

Interesting video

INTERSTATE STANDARD

Unified system of design documentation

RULES FOR DRAWING HARNESSES, CABLES AND WIRES

Unified system for design documentation.

Rules for making drawings of braids, cables and wires

Introduction date 01.01.77

APPROVED AND PUT INTO EFFECT by the Decree of the State Committee for Standards of the Council of Ministers of the USSR dated November 26, 1975 No. 3618

INSTEAD OF GOST 2.414-68

EDITION (January 2002) with Amendment No. 1 approved in July 1980 (IUS 10-80)

1. This standard establishes the rules for the implementation of drawings of bundles, cables and wires in the design documentation of products in all industries.

The standard fully complies with ST SEV 649-77.

Notes:

1. A harness drawing is an assembly drawing of a specified product, consisting of two or more insulated conductors (wires, cables) fastened into a bundle by interlacing, tying (thread, tape) or in some other way, and, if necessary, others constituent parts(connectors, lugs, etc.).

2. A drawing of a cable (wire) is:

drawing of a part made from one piece of material (cable or wire) indicated in the main inscription of the drawing;

assembly drawing of a specified product, consisting of one cable or wire in the form of a part or material and any other components (connectors, lugs, etc.).

(Revised edition, Rev. No. 1).

2. Drawings of harnesses, cables and wires must be made in accordance with the requirements of the standards, the unified system of design documentation and this standard.

3. In the drawings of bundles, cables and wires, individual conductors should be depicted in a simplified way, i.e. external outlines (Fig. 1, a), or conditionally, i.e. one line (Fig. 1, b). With a simplified image of conductors, it is allowed to highlight them graphically according to the example shown in Fig. 2. On the assembly drawings of bundles, cables and wires, the remaining components should be depicted in a simplified way.

4. Shielded conductors should be depicted: simplified - as shown in Fig. 3;

conditionally - in accordance with the requirements given in GOST 2.721-74.

5. Ribbon, thread and other similar material, which should be wrapped around the harness or

cable, should not be depicted in the drawing; instructions on the material and its application should be given in technical requirements drawing.

6. The drawing of the bundle or cable must contain all the dimensions necessary for the manufacture of the product (Fig. 4).

When depicting a bundle on a scale of 1: 1, it is allowed to apply only the dimensions of the sections depicted with a gap (Fig. 5).

The dimensions of the bending radii may not be specified.

With a conditional image of the bundle, it is allowed to apply the dimensions of individual sections of the bundle without extension and dimension lines (Fig. 6).

7. The harness, which in the assembled product should be located in different planes (Fig. 7, a), should be depicted, as a rule, deployed in the plane of the drawing (Fig. 7, b). It is allowed to depict the tourniquet in axonometric projections.

8. Separate sections of the conductor image are allowed to be shifted as shown in Fig. eight.

9. When drawing a bundle on two or more sheets, the trunk of the bundle with all branches (groups of wires and individual wires) extending directly from the trunk should be depicted on the first sheet, preferably on a reduced scale. Branching groups of wires should be depicted in full in the form of remote elements (Fig. 9) on subsequent sheets of the drawing, preferably on a scale of 1:1 (Fig. 10).

The dimensions defining the position of the end ramifications, not shown on the first sheet, must be applied on the first and subsequent sheets, as shown in Fig. 9 and 10.

10. In the drawing of a bundle or cable, each conductor (wire of a bundle or cable core) must

have the designation assigned to it on the drawing for electrical installation, or in the absence of such a drawing, on the electrical wiring diagram of the product being mounted.

11. The conductor designation should be applied near both ends of the conductor image (Fig. 4, 9, 10) and, if necessary, at the branching points. It is allowed to apply the designation of the conductor on the image of the marking tag (Fig. 5).

12. On the harness drawing, it is allowed to assign a symbol to a group of conductors at the place of its branching into separate wires, while the groups should be designated capital letters Russian alphabet in alphabetical order in accordance with the arrangement of groups in the image, counting, as a rule, from top to bottom in the direction from left to right (Fig. 5).

13. On the images of connecting devices or near them, the designations assigned to these devices on the electrical circuit diagram product or on the connection diagram (Fig. 6).

AT in cases where in the manufactured bundle (cable) the connecting devices should not be marked, it is allowed not to apply the markings on the drawing.

14. Instead of the image of the places of connection of conductors (wires of the bundle or cable cores), indications of connections can be given on the drawing of the bundle (cable) in the following ways:

in table, performed according to the rules given in GOST 2.413-72 (Sec. 2);

in connection table on the drawing field - on the first sheet of the drawing or its subsequent sheets;

in technical requirements of the drawing;

in the form of a schematic representation on the drawing field.

15. When performing a table harness on the drawing according to the rules given in GOST 2.413-72 (section 2), it is allowed to replace the column "Wire" in it with the column "Return address" indicating in it the addresses of connection of the second ends of the wires. In this case, the connection table should not be shown on the drawing; the position numbers of the wires (material) according to the specification of the bundle must be marked on the image of the bundle or indicated in the technical requirements of the drawing. Designations of conductors in these cases may not be applied.

16. The connection table should be made in the form:

The dimensions of the columns of the table are not specified in this standard.

AT the column "Conductor" must indicate the designation of the conductor.

AT column "Pos." the position number of the material of the bundle wire according to the specification must be indicated.

AT in the column "Connections" the addresses of the connections of both ends of the conductor must be indicated. In cases where the end of the conductor is ferruled or left free, reference should be made to the position number or to an additional figure. In this case, it is allowed to refer to the designation assigned to the group of conductors in accordance with the requirements given in clause 12, for example: "A, pos ...".

AT the column "Length" must indicate the length of the wire bundle, if it is not indicated in the image.

It is allowed to include other columns in the connection table according to the relevant industry standard, if their content is not a repetition of the data available in other design documents (specifications, drawings, etc.).

17. In the technical requirements of the drawing, instructions on connections may be given in cases where the conductors connect the same-name contacts of the connecting devices to each other.

18. On the schematic representation wiring harness connections (fig. 11) should be marked with thin solid lines, each of which represents, for example, a separate connector, identical lugs, free ends of conductors, etc. Wire (or jumper) connections should be indicated by connecting a solid main line (separately for each wire) to the corresponding thin lines or points of the schematic representation.

Wire pos. 30, except as otherwise noted.

The designations of the contacts of the connecting devices should be applied at the point indicating the connection, above or below the corresponding line. Above the line depicting the wire, the position number of the material of the wire according to the specification of the bundle must be applied.

Instructions for twisting wires can, if necessary, be given by the symbols given in GOST 2.721-74 or by text in the technical requirements of the drawing. It is allowed to indicate the position numbers of wire materials in the technical requirements of the drawing.

19. On the image of the bundle (cable), it is allowed not to put the position numbers of the lug tags, etc., if instructions for their installation are given in the technical requirements of the drawing or in the table of connections.

If you are doing electrical 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 and automation fitters, circuit designers. And if you don't have special training, it is unlikely that it will be possible to immediately understand all the subtleties. But it must be remembered that the symbols on the diagrams that are being developed for Russian consumers differ from the generally accepted standards abroad - in Europe, the USA, Japan.

History of designations on diagrams

Back in the Soviet years, when electrical engineering was developing rapidly, it became necessary to classify devices and designate them. It was then that the Unified System for Design Documentation (ESKD) appeared and state standards(GOST). Everything was standardized so that any engineer could read the legend on the drawings of his colleagues.

But in order to make out all the subtleties, you will need to listen to many lectures and study a lot of special literature. GOST is a huge document, and to fully study all the graphic symbols and their standard sizes, notes almost impossible. Therefore, it is necessary to always have a small "cheat sheet" at hand, which will help you navigate the whole variety of electrical components.

Wiring on drawings

Wiring is a generalized concept, it means conductors that have very low resistance. With their help, voltage is transmitted from the source of electricity to consumers. This is general concept, as there are many varieties of wiring.

People who do not understand wiring diagrams and features may decide that a conductor is an insulated cable connected to switches and sockets. But in fact, there are many types of conductors, and they are indicated in the diagrams in different ways.

Conductors on the diagrams

Even copper tracks on textolite circuit boards are a conductor, you can even say that this is an option electrical wiring. It is indicated on electrical diagrams as a straight connecting line passing from one element to another. In the same way, they are indicated on the diagram and electric wires high-voltage line laid in the fields between the poles. And in apartments, connecting wires between lamps, switches and sockets are also indicated by straight connecting lines.

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

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

The wiring plan is an incorrect definition, since wiring refers to both installation wires and cables. But if we significantly expand the list of elements, as is necessary on detailed diagram, it turns out that it is necessary to turn on more transformers, circuit breakers, devices protective shutdown, grounding, insulators.

Sockets on the diagrams

Sockets are plug-in 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 have been established for designating lighting apparatus and devices and various other electrical consumers on the drawings. Plug-in sockets can be divided into three categories:

1. Designed for open mounting.
2. Designed for concealed installation.
3. A block that includes a socket and a switch.

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

That's enough, there are no features for sockets, there are many options for execution. All devices have a degree of protection, the choice must be made based on the conditions under which it is to be used: humidity level, temperature, the presence of mechanical influences.

Switches on wiring diagrams

Switches are devices that break an electrical circuit. This can be done in automatic or manual mode. The conditional graphic designation by GOST is regulated, as is the case with sockets. The designation depends on the conditions under 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. Tripolar.

The diagrams must indicate the parameters of the disconnecting device. And by graphic designation you can see what type is used: simple with and without fixation, acoustic device (reacting to cotton) or optical. If there is a condition that the lighting turns on at dusk and turns off in the morning, an optical sensor and a small control circuit can be used.

Fuses (fuses)

There are many types of protection devices - fuses (disposable and self-resetting), many types of design, applications, different response speeds, reliability, use in certain conditions describes these devices. Symbol fuse is a rectangle, parallel long side through the center passes the most simple and cheap item able to protect electrical circuit from short circuit. It should be noted that such components are rarely used in electrical circuit diagrams. Symbols of another type can be found - these are self-restoring fuses, which, after opening the circuit, return to their original state.

The broad name for fuses is a fusible link. It is used in many devices, in electrical distribution boards. You can find them in disposable corks. But there are still devices used in high-voltage ones. They are structurally made of metal tips and the main ceramic part. Inside there is a segment of the conductor (its cross section is selected depending on what maximum current should pass through the circuit). The ceramic body is filled with sand to eliminate the possibility of ignition.

Circuit breakers

Symbols of devices of this type depend on the design, degree of protection. Device reusable can be used as a simple switch. In fact, it performs the functions of a fusible insert, but it is possible to transfer it to its original state - to close the circuit. The design consists of the following elements:

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

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

Grounding on the diagrams

Grounding is the connection of current conductors of an electric machine or device to the ground. In this case, both the ground and part of the circuit of the device have a negative potential. Due to grounding, in case of case breakdown, no damage to the device or electric shock will follow, the entire charge will go into the ground. Grounding is of the following types according to GOST:

1. General concept of grounding.
2. Clean ground (noiseless).
3. Protective type of grounding.
4. Connection to the mass (body) of the device.

Depending on which ground is used in the circuit, the symbol will be different. Important role when drawing up diagrams, the drawing of the element plays, it depends both on the specific section of the circuit and on the type of device.

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

Electric motors

On the electrical diagrams of cars, workshops, devices, you can often find electric motors. Moreover, in industry, more than 95% of all used motors 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 and buttons ("Start", "Stop", "Reverse" if necessary).

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

Wire color coding

In the case of a single-phase power supply, the phase conductor has a black, gray, purple, pink, red, orange, turquoise, white color. Most often you can find brown. This marking is generally accepted and is used in the preparation of diagrams, installation. is marked:

1. Blue color - zero worker (N).
2. Yellow with a green stripe - earth wire, protection (PE).
3. Yellow with green and labels blue color at 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 should also have a reference to the presence of marks. The conductor must be marked with the index PEN.

By functional purpose all conductors are separated as follows:

1. Black wires - for switching power circuits.
2. Red wires - for connections of control elements, measurement, signaling.
3. conductors of blue color- control, measurement and signaling when operating on direct current.
4. Blue marking is made for zero working conductors.
5. Yellow and green are ground and protection wires.

Alphanumeric symbols on the diagrams

The terminals have a symbol in the electrical circuits as follows:

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

Designation on wiring 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 is the middle conductor.

These are the symbols most often used in diagrams and drawings. They can be found in the descriptions. simple devices. If you need to read the circuit of a complex device, you will need a lot of knowledge. After all, there are still active elements, passive ones, 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 electricity. These are inductors. The symbol for 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 core made of transformer steel. But there may be designs of transformers that do not have a core, in which case there is nothing on the diagram between the coils. Such a symbolic designation of elements can also be found in the circuits of radio receiving equipment, for example.

AT last years in engineering, transformer steel is used less and less for the manufacture of transformers. It is very heavy, it is difficult to collect the plates into the core, there is a buzz when loosening. The use of ferromagnetic cores is much more efficient. They are solid, have the same permeability in all areas. But they have one minus - the complexity of the repair, since it is problematic to disassemble and assemble. The symbol of a transformer with such a core is practically no different from that in which steel is used.

Conclusion

These are far from all symbols of electrical circuits, the dimensions of the components are also regulated by GOST. Even simple arrows, connection points have requirements, their drawing is carried out strictly according to the rules. It is necessary to pay attention to one feature - the differences in the schemes made according to domestic standards and imported ones. Crossing conductors on foreign schemes marked with a semicircle. And there is such a thing as a sketch - this is an image of something without complying with the requirements of GOST for elements. Individual Requirements applied to the sketch itself. Such images can be performed for visual presentation future design, electrical wiring. Subsequently, a drawing is drawn up according to it, on which even the designations conditional cables and connections comply with standards.