The ability to read electrical diagrams is an important component, without which it is impossible to become a specialist in the field electrical installation work. Every novice electrician must know how sockets, switches, switching devices and even an electricity meter are designated on a wiring project in accordance with GOST. Next, we will provide readers of the site with symbols in electrical diagrams, both graphic and alphabetic.
As for the graphic designation of all elements used in the diagram, we will provide this overview in the form of tables in which the products will be grouped by purpose.
In the first table you can see how electrical boxes, panels, cabinets and consoles are marked on electrical circuits:
The next thing you should know is the symbol for power sockets and switches (including walk-through ones) on single-line diagrams of apartments and private houses:
As for lighting elements, lamps and fixtures 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 on the drawings:
By the way, here is a table useful for novice electricians, which shows what the ground loop looks like on a wiring plan, as well as the power line itself:
In addition, in 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 come across incomprehensible graphic symbols, like contact connections. Remember how these devices are designated on electrical diagrams:
In addition, you should be aware of what radio elements look like on projects (diodes, resistors, transistors, etc.):
That's all the conventional graphic symbols in the electrical circuits of power circuits and lighting. As you have already seen for yourself, there are quite a lot of components and remembering how each is designated is possible only with experience. Therefore, we recommend that you save all these tables so that when reading the wiring plan for a house or apartment, you can immediately determine what kind of circuit element is located in a certain place.
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They are built on the basis of contact symbols: making (Fig. 1, b), breaking (c, d) and switching (d, f). Contacts that simultaneously close or open two circuits are designated as shown in Fig. 1, (w, and and).
The initial position of the closing contacts on the electrical circuits is taken to be the open state of the switched electrical circuit, the breaking contacts are the closed state, and 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 provides for the reflection of such design features, such 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 (Fig. 2, a, b), and if later, with a stroke directed towards reverse side(Fig. 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. 2, e, f), and fixation is indicated by a circle on the symbol of its fixed part (Fig. 2, g, And).
The last two UGOs on electrical diagrams are used in cases where it is necessary to show a type of switching product whose contacts usually do not possess these properties.
The conventional graphic designation of switches on electrical diagrams (Fig. 3) is based on the symbols of the making and breaking contacts. This means that the contacts are fixed in both positions, i.e., they do not have self-return.
Rice. 3.
The letter code of products of this group is determined by the switched circuit and design 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 on the electrical diagrams 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 (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 (SA 4.1, SA4.2, SA4.3).
Rice. 4.
Similarly, based on the symbol of the switching contact, symbolic graphic symbols of two-position switches are built on electrical diagrams (Fig. 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 in Fig. 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. 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 (Fig. 5). Moreover, if the conventional graphic designation is based on the main contact symbol (see Fig. 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).
Rice. 5.
Rice. 6.
If it is necessary to show fixation, use symbols of contacts with fixation specially designed for this purpose (Fig. 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. 6, SB1.1, SB 1.2). 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).
(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 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 Fig. 7, SA1.1, SA1.2).
Rice. 7.
Rice. 8
To depict multi-position switches with complex switching, GOST provides several methods. Two of them are shown in Fig. 8. Switch SA1 - 5 positions (they are indicated by numbers; letters a-d 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 .
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 c and d, in the third - c and d, in the fourth - b and d.
Zorin A. Yu.
Electrical diagram- this is a text that describes with certain symbols the contents and operation of an electrical device or a set of devices, 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 diagrams, you should know the symbols - conventions and rules for deciphering their combinations.
The basis of any electrical circuit is graphic symbols various elements and devices, as well as connections between them. The language of modern circuits emphasizes in symbols the main functions that the depicted element performs in the circuit. All correct conventional graphic symbols of electrical circuit elements and their individual parts are given in the form of tables in the standards.
Conventional graphic symbols are formed from simple geometric shapes: squares, rectangles, circles, as well as solid and dashed lines and dots. Their combination according to a special system, which is provided for by the standard, makes it possible to easily depict everything that is required: various electrical apparatus, instruments, electric cars, lines of mechanical and electrical connections, types of winding connections, type of current, nature and methods of regulation, etc.
In addition, in the graphic symbols on electrical circuit diagrams In addition, special symbols are used to explain the operating features of a particular circuit element.
For example, there are three types of contacts - normally open, normally closed and switching. Legend reflect only the main function of the contact - closing and opening the circuit. To specify additional functionality For a specific contact, the standard provides for the use of special signs 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 options for designation on the diagrams. For example, there are several equivalent options for designating switching 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 required designation, then it is compiled based on the principle of operation of the element, designations adopted for similar types of devices, devices, machines in compliance with the design principles stipulated by the standard.
Standards. Conventional graphic symbols on electrical and automation diagrams:
GOST 2.710-81 Alphanumeric designations in electrical circuits:
When conducting electrical work Every person, one way or another, comes across the symbols that are in any electrical circuit. These schemes are very diverse, with various functions However, all graphic symbols are given uniform forms and correspond to the same elements in all diagrams.
Currently, not only domestic elements are used in electrical engineering and radio electronics, but also products manufactured by foreign companies. Imported electrical and radio elements make up a huge range. They are necessarily displayed in all drawings in the form of symbols. They determine not only the values of the basic electrical parameters, but also a complete list of them included in a particular device, as well as the relationship between them.
You need to thoroughly study all the elements that make up it and the principle of operation of the device as a whole. Typically, all information is found either in reference books or in the specification attached to the circuit. Positional designations characterize the relationship of the elements included in the device kit with their designations on the diagram. In order to graphically designate one or another electrical radio element, standard geometric symbolism is used, where each product is depicted separately or in combination with others. The meaning of each individual image largely depends on the combination of symbols with each other.
Connections between separate elements and conductors. In such cases, the standard designation of identical components and elements is of no small importance. This is why there are positional designations, where the types of elements, their design features and digital values are displayed in literal expression. Elements used in general procedure, are designated in the drawings as qualification ones, characterizing current and voltage, control methods, types of connections, pulse shapes, electronic communications and others.
STATE STANDARDS
Unified system of design documentation
CONVENTIONAL SYMBOLS
GRAPHICAL IN ELECTRICAL DIAGRAMS
SWITCHING DEVICES
AND CONTACT CONNECTIONS
GOST 2.755-87
(CT SEV 5720-86)
IPC PUBLISHING HOUSE OF STANDARDS
Moscow 1998
STATE STANDARD OF THE USSR UNION
|
Unified system of design documentation CONVENTIONAL GRAPHIC NOTATIONS SWITCHING DEVICES Unified system for design documentation. Graphic designs in diagrams. Commutational devices and contact connections |
GOST (CT SEV 5720-86) |
Date of introduction 01.01.88
This standard applies to manual or automated diagrams of products from all branches of industry and construction and establishes conventional graphic symbols for switching devices, contacts and their elements. This standard does not establish conventional graphic symbols on railway signaling, centralization and interlocking diagrams. Conventional graphic symbols of mechanical connections, drives and devices - according to GOST 2.721. Conventional graphic designations of the receiving parts of electromechanical devices - according to GOST 2.756. The dimensions of individual graphic symbols and the ratio of their elements are given in the Appendix. 1. General rules for constructing contact designations. 1.1. Switching devices on the diagrams should be shown in the position taken as the initial one, in which the starting contact system is de-energized. 1.2. Contacts of switching devices consist of moving and fixed contact parts. 1.3. To depict the main (basic) functional features of switching devices, conventional graphic designations of contacts are used, which can be made in a mirror image: 1) making contacts 2) breaking contacts 3) switching contacts 4) switching contacts with neutral central position 1.4. To explain the principle of operation of switching devices, if necessary, the qualifying symbols shown in Table 1 are depicted on their contact parts. 1.
Table 1
|
Name |
Designation |
| 1. Contactor function | |
| 2. Switch function | |
| 3.Disconnector function | |
| 4. Switch-disconnector function | |
| 5. Automatic triggering | |
| 6. Travel or limit switch function | |
| 7. Self-return | |
| 8. No self-return | |
| 9. Arc suppression | |
| Note. The designations given in paragraphs. 1 - 4, 7 - 9 of this table are placed on fixed contact parts, and the designations in paragraphs. 5 and 6 - on moving contact parts. | |
table 2
|
Name |
Designation |
| 1. Switching device contact: | |
| 1) switching without breaking the circuit (bridge) | |
| 2) with double circuit | |
| 3) with double opening | |
| 2. Pulse closing contact: | |
| 1) when triggered | |
| 2) upon return | |
| 3. Pulse normally open contact: | |
| 1) when triggered | |
| 2) upon return | |
| 3) when triggered and returned | |
| 4. A contact in a contact group that fires earlier in relation to other contacts in the group: | |
| 1) closing | |
| 2) opening | |
| 5. A contact in a contact group that triggers later in relation to other contacts in the group: | |
| 1) closing | |
| 2) opening | |
| 6. Contact without self-return: | |
| 1) closing | |
| 2) opening | |
| 7. Self-return contact: | |
| 1) closing | |
| 2) opening | |
| 8. Switching contact with a neutral central position, with self-return from the left position and without return from the right position | |
| 9. Contactor contact: | |
| 1) closing | |
| 2) opening | |
| 3) closing arc extinguishing | |
| 4) breaking arc extinguishing | |
| 5) closing with automatic operation | |
| 10. Switch contact | |
| 11. Disconnector contact | |
| 12. Switch-disconnector contact | |
| 13. Limit switch contact: | |
| 1) closing | |
| 2) opening | |
| 14. Temperature sensitive contact (thermal contact): | |
| 1) closing | |
| 2) opening | |
| 15. Normally closed contact with delay operating: | |
| 1) when triggered |
|
| 2) upon return |
|
| 3) when triggered and returned |
|
| 16. Normally closed contact with delay operating: | |
| 1) when triggered |
|
| 2) upon return |
|
| 3) when triggered and returned |
|
| Note to paragraphs. 15 and 16. Deceleration occurs when moving in the direction from the arc to its center. |
Table 3
|
Name |
Designation |
|
| 1. Switch closing contact: | ||
| 1) single pole | ||
|
Single line |
Multiline |
|
| 2) three-pole |
|
|
| 2. Closing contact of a three-pole switch with automatic operation of the maximum current |
|
|
| 3. Closing contact of a push-button switch without self-return, with opening and return of the control element: | ||
| 1) automatically | ||
| 2) by pressing the button a second time | ||
| 3) by pulling the button | ||
| 4) via a separate drive (example of pressing a reset button) | ||
| 4. Three-pole disconnector | ||
| 5. Three-pole switch-disconnector | ||
| 6. Manual switch |
|
|
| 7. Electromagnetic switch (relay) |
|
|
| 8. Limit switch with two separate circuits | ||
| 9. Thermal self-regulating switch Note. A distinction should be made in the representation of the contact and the thermal relay contact, depicted as follows | ||
| 10. Inertia switch | ||
| 11. Three-point mercury switch | ||
Table 4
|
Name |
Designation |
| 1. Single-pole multi-position switch (six-position example) |
|
| Note. Switch positions in which there are no switched circuits, or positions connected to each other, are indicated by short strokes (an example of a six-position switch that does not switch an electrical circuit in the first position and switches the same circuit in the fourth and sixth positions) |
|
| 2. Single pole, six position transfer switch |
|
| 3. Single-pole, multi-position switch with a moving contact that closes three adjacent circuits in each position |
|
| 4. Single-pole, multi-position switch with a moving contact that closes three circuits, excluding one intermediate |
|
| 5. Single-pole, multi-position switch with a moving contact, which in each subsequent position connects a parallel circuit to the circuits closed in the previous position |
|
| 6. Single-pole, six-position switch with a moving contact that does not open the circuit when moving from the third to the fourth position |
|
| 7. Two-pole, four-position switch |
|
| 8. A two-pole, six-position switch in which the third contact of the upper pole operates earlier, and the fifth contact later, than the corresponding contacts of the lower pole. |
|
| 9. Multi-position switch of independent circuits (example of six circuits) | |
| Notes to paragraphs. 19: | |
| 1. If it is necessary to indicate the limitation of movement of the switch drive, use a position diagram, for example: | |
| 1) the drive ensures the transition of the moving contact of the switch from position 1 to position 4 and back |
|
| 2) the drive ensures the transition of the moving contact from position 1 to position 4 and then to position 1; reverse movement is only possible from position 3 to position 1 |
|
| 2. The position diagram is connected to the moving contact of the switch by a mechanical connection line |
|
| 10. A switch with complex switching is depicted in the diagram in one of the following ways: 1) general designation (an example of the designation of an eighteen-position rotary switch with six terminals, designated A to F) |
|
| 2) designation according to design |
|
| 11. Switch two-pole, three-position with neutral position | |
| 12. Two-pole, three-position switch with self-return to neutral position |
Table 5
|
Name |
Designation |
| 1. Pin connection contact: | |
| 1) detachable connection: | |
| - pin |
|
| - nest |
|
| 2) collapsible connection |
|
| 3) permanent connection |
|
| 2. Sliding contact: | |
| 1) along a linear conductive surface | |
| 2) along several linear conductive surfaces | |
| 3) along an annular conductive surface | |
| 4) along several annular conductive surfaces Note. When making diagrams using a computer, it is allowed to use shading instead of blackening |
Table 6
|
Name |
Designation |
| 1. Detachable contact connection |
|
| 2. Four-wire detachable contact connection |
|
| 3. Four-wire connector pin |
|
| 4. Four-wire connector socket |
|
| Note. In paragraphs 2 - 4 digits inside rectangles indicate contact numbers | |
| 5. Detachable coaxial contact connection |
|
| 6. Contact jumpers | |
| Note. Type of connection, see table. 5, paragraph 1. | |
| 7. Terminal block Note: To indicate the types of contact connections, the following designations may be used: |
|
| 1) pads with removable contacts | |
| 2) pads with detachable and non-separable contacts | |
| 8. Switching jumper: | |
| 1) to open |
|
| 2) with the pin removed | |
| 3) with the socket removed | |
| 4) to switch | |
| 9. Connection with protective contact |
|
Table 7
|
Name |
Designation |
| 1. Finder brush with circuit breaker when switching |
|
| 2. Finder brush without breaking the circuit when switching |
|
| 3. Finder field contact (output) | |
| 4. Group of contacts (outputs) of the finder field |
|
| 5. Contact finder field |
|
| 6. Finder field contact with initial position Note. The initial position designation is used if necessary | |
| 7. Contact finder field with images of contacts (outputs) |
|
| 8. Finder field showing groups of contacts (outputs) |
|
Table 8
|
Name |
Designation |
| 1. One-move finder without brushes returning to their original position | |
| 2. One-motion finder with brushes returning to their original position. | |
| Note. When using a finder in a four-wire path, the designation of a finder with the brushes returning to their original position is used |
