Wiring diagrams for the designation of elements. The designation of the electric meter on the diagram. Elements of electrical circuits, devices
Reading electrical diagrams is a necessary skill for representing the operation of electrical networks, nodes, as well as various equipment. Not a single specialist will proceed with the installation of equipment until he has familiarized himself with the regulatory accompanying documents.
Schematic diagrams allow the developer to convey a complete report about the product in a compressed form to the user using conditionally graphical symbols (UGO). To avoid confusion and waste when assembling according to drawings, alphanumeric designations are included in the unified design documentation system (ESKD). All circuit diagrams are developed and applied in full accordance with GOSTs (21.614, 2.722-68, 2.763-68, 2.729-68, 2.755-87). The GOST describes the elements, provides a decoding of the values.
Reading blueprints
The circuit diagram shows all the elements, parts and networks that make up the drawing, electrical and mechanical connections. Reveals the full functionality of the system. All elements of any electrical circuit correspond to the designations positioned in GOST.
A list of documents is attached to the drawing, in which all elements and their parameters are prescribed. Components are listed in alphabetical order, taking into account numerical sorting. The list of documents (specification) is indicated on the drawing itself, or is taken out as separate sheets.
The order of studying the drawings
First, the drawing type is determined. According to GOST 2.702-75, each graphic document corresponds to an individual code. All electrical drawings have the letter designation "E" and the corresponding digital value from 0 to 7. The code "E3" corresponds to the electrical circuit diagram.
Reading the circuit diagram:
- Visually get acquainted with the presented drawing, pay attention to the indicated notes and technical requirements.
- Find on the schematic image all the components indicated in the list of the document;
- Determine the power source of the system and the type of current (single-phase, three-phase);
- Find the main nodes, and determine their power source;
- Familiarize yourself with the elements and devices of protection;
- To study the control method indicated on the document, its tasks and algorithm of actions. Understand the sequence of actions of the device when starting, stopping, short circuit;
- Analyze the operation of each section of the chain, determine the main components, auxiliary elements, study the technical documentation of the listed parts;
- Based on the studied data of the document, draw a conclusion about the processes occurring in each link of the chain shown in the drawing.
Knowing the sequence of actions, alphanumeric symbols, you can read any electrical circuit.
Graphic symbols
The circuit diagram has two varieties - single-line and full. On a single-line drawing, only a power wire with all elements is drawn, if the main network does not differ in individual additions from the standard one. Two or three slashes applied to the wire line indicate a single-phase or three-phase network, respectively. The entire network is drawn in full and generally accepted symbols are affixed in electrical circuits.
Single line electrical circuit diagram, single phase network
Types and meaning of lines
- Thin and thick solid lines - in the drawings depict the lines of electrical, group communication, lines on the elements of the UGO.
- Dashed line - indicates the shielding of the wire or devices; denotes a mechanical connection (motor - gearbox).
- A thin dash-dotted line - is intended to highlight groups of several components that make up parts of a device, or a control system.
- Dash-dotted with two dots - the line is disconnecting. Shows a breakdown of important elements. Indicates an object remote from the device that is associated with a mechanical or electrical system.
Network connecting lines are shown in full, but according to the standards, they are allowed to be cut off if they interfere with the normal understanding of the circuit. A break is indicated by arrows, next to it are the main parameters and characteristics of electrical circuits.
A bold dot on the lines indicates a connection, a soldering of wires.
Electromechanical components
Schematic representation of electromechanical links and contacts
A - UGO coils of an electromechanical element (magnetic starter, relay)
B - thermal relay
C - device coil with mechanical blocking
D - contacts making (1), breaking (2), switching (3)
E - button
F - designation of a switch (knife switch) on the electrical circuit of the UGO of some measuring instruments. A complete list of these elements is given in GOST 2.729 68 and 2.730 73.
Elements of electrical circuits, devices
| Number in the picture | Description | Number in the picture | Description |
|---|---|---|---|
| 1 | Electricity meter | 8 | electrolytic capacitor |
| 2 | Ammeter | 9 | Diode |
| 3 | Voltmeter | 10 | Light-emitting diode |
| 4 | temperature sensor | 11 | Diode optocoupler |
| 5 | Resistor | 12 | Image of npn transistor |
| 6 | Rheostat (variable resistor) | 13 | Fuse |
| 7 | Capacitor |
UGO time relays, buttons, switches, limit switches are often used in the development of electric drive circuits.
Schematic representation of a fuse. When reading an electrical circuit, you should carefully consider all the lines and parameters of the drawing so as not to confuse the purpose of the element. For example, a fuse and a resistor have minor differences. In the diagrams, the power line is depicted passing through the fuse, the resistor is drawn without internal elements.
The image of the circuit breaker in the full diagram
Contact switching device. Serves as automatic protection of the electrical network from accidents, short circuits. Operated mechanically or electrically.
Circuit breaker on a single line diagram
The transformer is a steel core with two windings. There are single and three-phase, step-up and step-down. It is also divided into dry and oil, depending on the method of cooling. Power varies from 0.1 MVA to 630 MVA (in Russia).
UGO transformers
Designation of current transformers on a complete (a) and single-line (c) circuit
Graphic designation of electrical machines (EM)
Electric motors, depending on the type, are capable of more than just consuming energy. When developing industrial systems, motors are used that, when there is no load, generate energy into the network, thereby reducing costs.
A - Three-phase electric motors:
1 - Asynchronous with squirrel-cage rotor
2 - Asynchronous with squirrel-cage rotor, two-speed
3 - Asynchronous with a phase rotor
4 - Synchronous electric motors; generators.
B - DC commutator motors:
1 - with excitation of the winding from a permanent magnet
2 - Electric machine with excitation coil
In conjunction with electric motors, the diagrams show magnetic starters, soft starters, and a frequency converter. These devices are used to start electric motors, the smooth operation of the system. The last two elements protect the network from "drawdown" of voltage in the network.
UGO magnetic starter in the diagram
Switches perform the function of switching equipment. Disable and enable certain sections of the network, as needed.
Graphic symbols in the electrical circuits of mechanical switches
Conditional graphic designations of sockets and switches in electrical circuits. They are included in the developed drawings of the electrification of houses, apartments, and industries.
Bell on the electrical diagram according to UGO standards with the indicated size
UGO dimensions in electrical diagrams
On the diagrams, the parameters of the elements included in the drawing are applied. Complete information about the element is written, capacitance if it is a capacitor, nominal voltage, resistance for a resistor. This is done for convenience, so as not to make a mistake during installation, not to waste time calculating and selecting the components of the device.
Sometimes the nominal data does not indicate, in this case the element parameters do not matter, you can select and install a link with a minimum value.
The accepted dimensions of the UGO are prescribed in the GOSTs of the ESKD standard.
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Dimensions in ESKD
The sizes of graphic and alphabetic images in the drawing, the thickness of the lines should not differ, but it is permissible to change them proportionally in the drawing. If in the symbols on various GOST electrical circuits there are elements that do not have information about the dimensions, then these components are performed in sizes corresponding to the standard UGO image of the entire circuit.
UGO elements that are part of the main product (device) can be drawn in a smaller size compared to other elements.
Along with the UGO, for a more accurate definition of the name and purpose of the elements, a letter designation is applied to the diagrams. This designation is used for references in text documents and for drawing on an object. With the help of a letter designation, the name of the element is determined, if this is not clear from the drawing, technical parameters, quantity.
Additionally, one or more numbers are indicated with the letter designation, usually they explain the parameters. An additional letter code indicating the denomination, model, additional data is prescribed in the accompanying documents, or is placed in a table on the drawing.
To learn how to read electrical circuits, it is not necessary to know by heart all the letter designations, graphic images of various elements, it is enough to navigate in the relevant ESKD GOSTs. The standard includes 64 GOST documents, which reveal the main provisions, rules, requirements and designations.
The main designations used on the diagrams according to the ESKD standard are given in Tables 1 and 2.
Table 1
|
First letter of the code (mandatory) |
Group of element types | Element Type Examples |
| A | Devices | Amplifiers, telecontrol devices, lasers, masers |
| B | Loudspeakers, microphones, thermoelectric sensing elements, ionizing radiation detectors, sound pickups, selsyns | |
| C | Capacitors | |
| D | Integrated analog digital circuits, logic elements, memory devices, delay devices | |
| E | Elements are different | Lighting devices, heating devices |
| F | Discrete flow and voltage protection elements, fuses, arresters | |
| G | Generators, power supplies, quartz oscillators | Batteries, accumulators, electrochemical and electrothermal sources |
| H | Indicating and signaling devices | Sound and light signaling devices, indicators |
| K | Relays, contactors, starters | Current and voltage relays, electrothermal relays, time relays, contactors, magnetic starters |
| L | Chokes for fluorescent lighting | |
| M | Engines | DC and AC motors |
| P | Indicating, recording and measuring instruments, counters, clocks | |
| Q | Disconnectors, short circuiters, circuit breakers (power) | |
| R | Resistors | Variable resistors, potentiometers, varistors, thermistors |
| S | Switching devices in control, signaling and measuring circuits | Switches, switches, switches triggered by various influences |
| T | Current and voltage transformers, stabilizers | |
| U | Converters of electrical quantities into electrical, communication devices | Modulators, demodulators, discriminators, inverters, frequency converters, rectifiers |
| V | Electronic tubes, diodes, transistors, thyristors, zener diodes | |
| W | Microwave lines and elements, antennas | Waveguides, dipoles, antennas |
| X | Contact connections | Pins, sockets, collapsible connections, current collectors |
| Y | Electromagnetic clutches, brakes, cartridges | |
| Z | Terminal devices, filters, limiters | Modeling lines, quartz filters |
The main two-letter designations are given in Table 2
| First letter of the code (mandatory) | Group of element types | Element Type Examples | Two letter code |
| A | Device (general designation) | ||
| B | Converters of non-electrical quantities into electrical quantities (except generators and power supplies) or vice versa analog or multi-digit converters or sensors for indicating or measuring | Speaker | BA |
| Magnetostrictive element | BB | ||
| Detector of ionizing elements | BD | ||
| Selsyn - receiver | BE | ||
| Phone (capsule) | bf | ||
| Selsyn - sensor | BC | ||
| Thermal sensor | BK | ||
| Photocell | BL | ||
| Microphone | BM | ||
| Pressure meter | BP | ||
| Piezo element | BQ | ||
| Speed sensor (tachogenerator) | BR | ||
| Pickup | BS | ||
| Speed sensor | BV | ||
| C | Capacitors | ||
| D | Integrated circuits, microassemblies | Circuit integrated analog | DA |
| Integrated circuit, digital, logic element | DD | ||
| Information storage device | D.S. | ||
| delay device | DT | ||
| E | Elements are different | A heating element | EK |
| Lighting lamp | EL | ||
| Igniter | ET | ||
| F | Surge arresters, fuses, protective devices | Discrete instantaneous current protection element | FA |
| Discrete current protection element of inertial action | FP | ||
| fuse | FU | ||
| Discrete voltage protection element, arrester | FV | ||
| G | Generators, power supplies | Battery | GB |
| H | Indicator and signal elements | Sound alarm device | HA |
| Symbolic indicator | HG | ||
| Light signaling device | HL | ||
| K | Relays, contactors, starters |
Current relay | KA |
| Relay index | KH | ||
| Relay electrothermal | KK | ||
| Contactor, magnetic starter | KM | ||
| Time relay | KT | ||
| Voltage relay | KV | ||
| L | Inductors, chokes | Fluorescent lighting choke | LL |
| M | Engines | - | - |
| P | Instruments, measuring equipment | Ammeter | PA |
| Pulse counter | PC | ||
| Frequency meter | PF | ||
| Note. PE combination not allowed | Active energy meter | PI | |
| Reactive Energy Meter | PK | ||
| Ohmmeter | PR | ||
| Recording device | PS | ||
| Clock, action time meter | PT | ||
| Voltmeter | PV | ||
| Wattmeter | PW | ||
| Q | Switches and disconnectors in power circuits | Automatic switch | QF |
| short circuit | QK | ||
| Disconnector | QS | ||
| R | Resistors | Thermistor | RK |
| Potentiometer | RP | ||
| Measuring shunt | RS | ||
| Varistor | EN | ||
| S | Switching devices in control, signaling and measuring circuits. Note. The designation SF is used for devices that do not have power circuit contacts. |
Breaker or switch | SA |
| push button switch | SB | ||
| Automatic switch | SF | ||
| Switches triggered by various influences: - from the level |
SL | ||
| - from pressure | SP | ||
| - from the position (travel) | SQ | ||
| - on the frequency of rotation | SR | ||
| - on temperature | SK | ||
| T | Transformers, autotransformers | Current transformer | TA |
| Electromagnetic Stabilizer | TS | ||
| voltage transformer | TV | ||
| U | Communication devices. Electrical to electrical converters |
Modulator | UB |
| Demodulator | UR | ||
| Discriminator | UI | ||
| Frequency converter, inverter, frequency generator, rectifier | USD | ||
| V | Electrovacuum devices, semiconductor | diode, zener diode | VD |
| Electrovacuum device | VL | ||
| Transistor | VT | ||
| Thyristor | VS | ||
| W | Lines and elements of microwave antennas | coupler | W.E. |
| short circuit | WK | ||
| Valve | WS | ||
| Transformer, heterogeneity, phase shifter | wt | ||
| Attenuator | WU | ||
| Antenna | WA | ||
| X | Contact connections | Current collector, sliding contact | XA |
| Pin | XP | ||
| Nest | XS | ||
| Collapsible connection | XT | ||
| High frequency connector | XW | ||
| Y | Mechanical devices with electromagnetic drive | Electromagnet | YA |
| Brake with electromagnetic drive | YB | ||
| Coupling with electromagnetic drive | YC | ||
| Electromagnetic chuck or plate | YH | ||
| Z | Terminal devices Filters. Limiters | limiter | ZL |
| Quartz filter | ZQ |
Related videos
Almost all UOS, all products of radio electronics and electrical engineering manufactured by industrial organizations and enterprises, home craftsmen, young technicians and radio amateurs, contain a certain amount of various purchased ERI and elements produced mainly by domestic industry. But lately there has been a tendency to use ERE and foreign-made components. These include, first of all, PPP, capacitors, resistors, transformers, chokes, electrical connectors, batteries, HIT, switches, installation products and some other types of ERE.
Used purchased components or independently manufactured ERE are necessarily reflected in the circuit diagrams and wiring diagrams of devices, in drawings and other TD, which are carried out in accordance with the requirements of ESKD standards.
Particular attention is paid to circuit diagrams, which determine not only the main electrical parameters, but also all the elements included in the device and the electrical connections between them. To understand and read circuit diagrams, you must carefully familiarize yourself with the elements and components included in them, know exactly the scope and principle of operation of the device in question. As a rule, information about the applied ERE is indicated in reference books and specifications - a list of these elements.
The connection of the list of ERE components with their conditional graphic designations is carried out through reference designations.
To construct conventional graphic symbols for ERE, standardized geometric symbols are used, each of which is used separately or in combination with others. Moreover, the meaning of each geometric image in the symbol in many cases depends on the combination with which other geometric symbol it is used.
The standardized and most commonly used ERE graphic symbols in circuit diagrams are shown in Fig.1. These designations apply to all components of circuits, including ERE, conductors and connections between them. And here, the condition for the correct designation of the same type of ERE components and products is of paramount importance. For this purpose, positional designations are used, the mandatory part of which is the letter designation of the type of element, the type of its construction and the digital designation of the ERE number. The diagrams also use an additional part of the designation of the ERE position, indicating the function of the element, in the form of a letter. The main types of letter designations of circuit elements are given in Table 1.
The designations on the drawings and diagrams of elements of general use refer to qualification ones, establishing the type of current and voltage, the type of connection, the methods of regulation, the shape of the pulse, the type of modulation, electrical connections, the direction of transmission of current, signal, energy flow, etc.
At present, the population and the trade network use a significant number of various electronic devices and devices, radio and television equipment, which are manufactured by foreign firms and various joint-stock companies. In stores, you can purchase various types of ERI and ERE with foreign designations. In table. 1. 2 provides information on the most common ERE in foreign countries with the appropriate designations and their analogues of domestic production.
This information is published for the first time in such volume.
1- transistor structure p-n-p in the case, general designation;
2- transistor structure p-p-p in the case, general designation,
3 - field effect transistor with pn junction and n channel,
4 - field effect transistor with p-n junction and p channel,
5 - unijunction transistor with an n-type base, b1, b2 - base terminals, e - emitter terminal,
6 - photodiode,
7 - rectifier diode,
8 - zener diode (avalanche rectifier diode) one-sided,
9 - thermal-electric diode,
10 - diode thyristor, erasable in the opposite direction;
11 - zener diode (diodolavin rectifier) with double-sided
conductivity,
12 - triode thyristor.
13 - photoresistor,
14 - variable resistor, rheostat, general designation,
15 - variable resistor,
16 - variable resistor with taps,
17 - construction resistor-potentiometer;
18 - thermistor with a positive temperature coefficient of direct heating (heating),
19 - varistor,
20 - fixed capacitor, general designation,
21 - polarized capacitor of constant capacitance;
22 - oxide polarized electrolytic capacitor, general designation;
23 - constant resistor, general designation;
24 - constant resistor with a rated power of 0.05 W;
25 - constant resistor with a rated power of 0.125 W,
26 - constant resistor with a rated power of 0.25 W,
27 - constant resistor with a rated power of 0.5 W,
28 - constant resistor with a rated power of 1 W,
29 - constant resistor with a rated power dissipation of 2 W,
30 - constant resistor with a rated power dissipation of 5 W;
31 - constant resistor with one symmetrical additional tap;
32 - constant resistor with one asymmetrical additional tap;
Conventional graphic symbols of ERE in electrical, radio engineering and automation circuits
33 - non-polarized oxide capacitor,
34 - pass-through capacitor (arc denotes body, external electrode),
35 - capacitor of variable capacity (the arrow indicates the rotor);
36 - tuning capacitor, general designation
37 - varicap.
38 - noise suppression capacitor;
39 - LED,
40 - tunnel diode;
41 - incandescent lighting and signal lamp
42 - electric bell
43 - galvanic or battery cell;
44 - electrical communication line with one branch;
45 - electrical communication line with two branches;
46 - a group of wires connected to one electrical connection point. two wires;
47 - four wires connected to one electrical connection point;
48 - a battery of galvanic cells or a battery;
49 - coaxial cable. The screen is connected to the body;
50 - winding of a transformer, autotransformer, inductor, magnetic amplifier;
51 - working winding of the magnetic amplifier;
52 - control winding of the magnetic amplifier;
53 - a transformer without a core (magnetic circuit) with a constant connection (dots indicate the beginning of the windings);
54 - transformer with a magnetodielectric core;
55 - inductor, choke without magnetic circuit;
56 - single-phase transformer with a ferromagnetic core and a screen between the windings;
57 - single-phase three-winding transformer with a ferromagnetic magnetic circuit with a tap in the secondary winding;
58 - single-phase autotransformer with voltage regulation;
59 - fuse;
60 - fuse switch;
b1 - fuse-disconnector;
62 - connection pin detachable;
63 - amplifier (the direction of signal transmission is indicated by the top of the triangle on the horizontal communication line);
64 - pin of detachable contact connection;
Conventional graphic symbols of ERE in electrical, radio engineering and automation circuits
65 - socket for detachable contact connection,
66 - collapsible connection contact, for example, using a clamp
67 - contact of a non-separable connection, for example, carried out by soldering
68 - single-pole push-button switch with NO contact
self-return
69 - switching device opening contact, general designation
70 - contact of the switching device (switch, relay) closing, general designation. The switch is single-pole.
71 - switching device contact, general designation. Single pole two way switch.
72 - three-position switching contact with neutral position
73 - closing contact without self-return
74 - push-button switch with break contact
75 - push-button exhaust switch with closing contact
76 - push-button switch with button return,
77 - push-button exhaust switch with NC contact
78 - push-button switch with return by pressing the button again,
79 - electrical relay with make, break and changeover contacts,
80 - relay polarized in one direction of current in the winding with a neutral position
81 - relay polarized in both directions of current in a winding with a neutral position
82 - electrothermal relay without self-return, with return by pressing the button again,
83- plug single-pole connection
84 - socket for a five-wire plug-in connection,
85 pin connector coaxial connection
86 - contact socket
87 - four-wire connection pin,
88 four-wire socket
89 - jumper switching opening circuit
Symbols of circuit elements
Standard conditional graphic and letter designations of elements of electrical circuits
| E | EMF source | |
| R | Resistor, active resistance | |
| L | Inductance, coil | |
| C | capacitance, capacitor | |
| G | Alternator, feed circuit | |
| M | AC motor | |
| T | Transformer | |
| Q | Power switch (for voltage over 1kV) | |
| QW | Load break switch | |
| QS | Disconnector | |
| F | Fuse | |
| Busbars with connections | ||
| Detachable connection | ||
| QA | Automatic switch for voltage up to 1 kV | |
| KM | Contactor, magnetic starter | |
| S | knife switch | |
| TA | Current transformer | |
| TA | Zero sequence current transformer | |
| TV | Three-phase or three single-phase voltage transformers | |
| F | Discharger | |
| To | Relay | |
| KA, KV, KT, KL | Relay winding | |
| KA, KV, KT, KL | NO relay contact | |
| KA, KV, KT, KL | Relay opening contact | |
| CT | Timing relay contact | |
| CT | Time relay contact closing with return delay | |
| Measuring instrument | ||
| measuring instrument | ||
| Ammeter | ||
| Voltmeter | ||
| Wattmeter | ||
| Varmeter |
Site materials used.
If for an ordinary person the perception of information occurs when reading words and letters, then for locksmiths and installers they are replaced by alphabetic, numerical or graphic symbols. The difficulty is that while the electrician graduates, gets a job, learns something in practice, as new SNiPs and GOSTs appear, according to which adjustments are made. Therefore, do not try to learn all the documentation and immediately. It is enough to gain basic knowledge, and add up-to-date data in the course of working days.
For circuit designers, instrumentation fitters, electricians, the ability to read an electrical circuit is a key quality and qualification indicator. Without special knowledge, it is impossible to immediately understand the intricacies of designing devices, circuits and methods of connecting electrical components.
Types and types of electrical circuits
Before you start studying the existing designations of electrical equipment and its connections, you need to understand the typology of circuits. On the territory of our country, standardization was introduced in accordance with GOST 2.701-2008 of July 1, 2009, according to “ESKD. Scheme. Types and types. General requirements".
Based on this standard, all schemes are divided into 8 types:
- United.
- Located.
- General.
- Connections.
- Mounting connections.
- Complete principal.
- Functional.
- Structural.
Among the existing 10 species indicated in this document, there are:
- Combined.
- divisions.
- Energy.
- Optical.
- Vacuum.
- Kinematic.
- Gas.
- Pneumatic.
- Hydraulic.
- Electrical.
For electricians, it is of the greatest interest among all the above types and types of circuits, as well as the most popular and frequently used in work - the electrical circuit.
The latest GOST, which came out, is supplemented by many new designations, relevant today with the code 2.702-2011 of 01/01/2012. The document is called "ESKD. Rules for the implementation of electrical circuits ”, refers to other GOSTs, among which are those mentioned above.
The text of the regulation sets out clear requirements in detail for electrical circuits of all types. Therefore, it is this document that should be guided during installation work with electrical circuits. The definition of the concept of an electrical circuit, according to GOST 2.702-2011, is as follows:
"Under the electrical circuit should be understood a document containing the symbols of the parts of the product and / or individual parts with a description of the relationship between them, the principles of operation from electrical energy."
After the definition, the document contains the rules for the implementation on paper and in software environments of the designations of contact connections, wire marking, lettering and graphic representation of electrical elements.
It should be noted that more often in home practice only three types of electrical circuits are used:
- Mounting- for the device, a printed circuit board is depicted with the arrangement of elements with a clear indication of the place, denomination, the principle of fastening and leading to other parts. Wiring diagrams for residential premises indicate the number, location, rating, connection method and other precise instructions for installing wires, switches, lamps, sockets, etc.
- Fundamental- they indicate in detail the connections, contacts and characteristics of each element for networks or devices. Distinguish between full and linear circuit diagrams. In the first case, control, control of elements and the power circuit itself are depicted; in a linear scheme, they are limited only to a chain with the image of the remaining elements on separate sheets.
- Functional- here, without detailing the physical dimensions and other parameters, the main components of the device or circuit are indicated. Any detail can be represented as a block with a letter designation, supplemented with links to other elements of the device.
Graphic symbols in electrical circuits
Documentation, which indicates the rules and methods for graphic designation of circuit elements, is represented by three GOSTs:
- 2.755-87 - graphic symbols for contact and switching connections.
- 2.721-74 - graphic symbols for parts and assemblies of general use.
- 2.709-89 - graphic symbols in electrical diagrams of circuit sections, equipment, contact connections of wires, electrical elements.
In the standard with the code 2.755-87, it is used for diagrams of single-line electrical panels, conditional graphic images (UGO) of thermal relays, contactors, knife switches, circuit breakers, and other switching equipment. There is no designation in the standards of difavtomatov and RCD.
On the pages of GOST 2.702-2011, the image of these elements is allowed in an arbitrary order, with explanations, decoding of the UGO and the circuit of difavtomatov and RCD itself.
GOST 2.721-74 contains UGOs used for secondary electrical circuits.
IMPORTANT: To designate switching equipment, there is:
4 base images UGO
9 functional signs of UGO
| UGO | Name |
| Arc quenching | |
| No self-return | |
| self-return | |
| Limit or travel switch | |
| With automatic actuation | |
| switch-disconnector | |
| Disconnector | |
| Switch | |
| Contactor |
IMPORTANT: Designations 1 - 3 and 6 - 9 are applied to fixed contacts, 4 and 5 are placed on moving contacts.
Basic UGOs for single-line electrical switchboard diagrams
| UGO | Name |
| Thermal relay | |
| contactor contact | |
| Knife switch - load switch | |
| Automatic - automatic switch | |
| Fuse | |
| Differential circuit breaker | |
| RCD | |
| voltage transformer | |
| Current transformer | |
| Knife switch (load switch) with fuse | |
| Motor protection circuit breaker (with built-in thermal relay) | |
| A frequency converter | |
| electricity meter | |
| Normally open contact with "reset" button or other push-button switch, with reset and opening by means of a special drive of the control element | |
| Normally open contact with pushbutton, with reset and opening by retracting the button of the operating element | |
| Normally open contact with pushbutton, with reset and opening by repeated pressing of the button of the operating element | |
| Normally open contact with pushbutton, with reset and automatic opening of the operating element | |
| N/O contact with delayed action, which is initiated on return and operation | |
| N/O contact with delayed action, which is initiated only when triggered | |
| Slow-acting make contact that is activated on return and trip | |
| N/O contact with delayed action that only trips on return | |
| N/O contact with delayed action that only closes when triggered | |
| Timing relay coil | |
| photorelay coil | |
| Pulse relay coil | |
| General designation of a relay coil or contactor coil | |
| Indicator lamp (light), lighting | |
| motor drive | |
| Terminal (collapsible connection) | |
| Varistor, surge arrester (surge arrester) | |
| Discharger | |
Socket (plug connection):
|
|
| A heating element |
Designation of electrical measuring instruments for characterizing circuit parameters
GOST 2.271-74 adopted the following designations in electrical panels for tires and wires:
Letter designations in electrical circuits
The standards for the letter designation of elements on electrical diagrams are described in the GOST 2.710-81 standard with the title of the text “ESKD. Alphanumeric designations in electrical circuits. The mark for difavtomatov and RCD is not indicated here, which is prescribed in clause 2.2.12 of this standard as a designation with multi-letter codes. The following letter codings are accepted for the main elements of electrical panels:
| Name | Designation |
| Automatic switch in the power circuit | QF |
| Automatic switch in the control circuit | SF |
| Circuit breaker with differential protection or difavtomat | QFD |
| Breaker or load switch | QS |
| RCD (residual current device) | QSD |
| Contactor | KM |
| Thermal relay | F, KK |
| Time relay | KT |
| Voltage relay | KV |
| impulse relay | KI |
| photorelay | KL |
| OPN, arrester | FV |
| fuse | FU |
| voltage transformer | TV |
| Current transformer | TA |
| A frequency converter | USD |
| Ammeter | PA |
| Wattmeter | PW |
| Frequency meter | PF |
| Voltmeter | PV |
| Active energy meter | PI |
| Reactive energy meter | PK |
| heating element | EK |
| Photocell | BL |
| lighting lamp | EL |
| Light bulb or indicator light | HL |
| Plug connector or socket | XS |
| Switch or circuit breaker in control circuits | SA |
| Pushbutton switch in control circuits | SB |
| Terminals | XT |
Image of electrical equipment on the plans
Despite the fact that GOST 2.702-2011 and GOST 2.701-2008 take into account such a type of electrical circuit as a “layout diagram” for the design of structures and buildings, it is necessary to be guided by the standards of GOST 21.210-2014, which indicate “SPDS.
Images on the plans of conditional graphic wiring and electrical equipment. The document establishes UGO on plans for laying electrical networks for electrical equipment (lamps, switches, sockets, electrical panels, transformers), cable lines, busbars, tires.
The use of these symbols is used to draw up drawings of electrical lighting, power electrical equipment, power supply and other plans. The use of these designations is also used in the schematic single-line diagrams of electrical panels.
Conditional graphic images of electrical equipment, electrical devices and electrical receivers
The contours of all depicted devices, depending on the information richness and complexity of the configuration, are taken in accordance with GOST 2.302 on the scale of the drawing according to the actual dimensions.
Conditional graphic designations of wiring lines and conductors
Conditional graphic images of tires and busbars
IMPORTANT: The design position of the bus duct must exactly match on the diagram with the place of its attachment.
Conditional graphic images of boxes, cabinets, shields and consoles
Conditional graphic symbols of switches, switches
On the pages of the GOST 21.210-2014 documentation for push-button switches, dimmers (dimmers), a separate designation is not provided. In some schemes, according to clause 4.7. normative act, arbitrary designations are used.
Conventional graphic designations of socket outlets
Conditional graphic designations of lamps and spotlights
The updated version of GOST contains images of luminaires with fluorescent and LED lamps.
Conditional graphic designations of control and management devices
Conclusion
The given graphic and alphabetic images of electrical components and electrical circuits are not a complete list, since the standards contain many special characters and codes that are practically not used in everyday life. To read electrical circuits, you will need to take into account many factors, first of all, the country of the manufacturer of the device or electrical equipment, wiring and cables. There is a difference in marking and symbol on the diagrams, which can be quite confusing.
Secondly, you should carefully consider such areas as the intersection or lack of a common network for wires located with an overlay. On foreign diagrams, if the bus or cable does not have a common power supply with intersecting objects, a semicircular continuation is drawn at the point of contact. This is not used in domestic schemes.
If the diagram is depicted without complying with the standards established by GOSTs, then it is called a sketch. But for this category there are also certain requirements, according to which, according to the above sketch, an approximate understanding of the future electrical wiring or device design should be drawn up. Drawings can be used to draw up more accurate drawings and diagrams from them, with the necessary designations, markings and scales.
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
Sooner or later, when carrying out electrical installation or electrical repair work, you have to deal with electrical circuits that contain many alphanumeric and conventionally graphic symbols. The latter will be discussed in this article. There are a large number of types of electrical circuit elements that have a variety of functions, therefore, there is no single document that determines the correct graphic designation of all elements that can be found on the diagrams. Below, the tables show some examples of conditional graphic images of electrical equipment and wiring, elements of electrical circuits in diagrams taken from various currently valid documents. You can download the entire GOST for free by clicking on the links at the bottom of the page.
Free download GOST
- GOST 21.614 Images of conditional graphic electrical equipment and wiring in the original
- GOST 2.722-68 Conditional graphic designations in schemes. Electrical machines
- GOST 2.723-68 Conditional graphic designations in schemes. Inductors, reactors, chokes, transformers, autotransformers and magnetic amplifiers
- GOST 2.729-68 Conditional graphic designations in schemes. Electrical measuring instruments
- GOST 2.755-87 Conditional graphic designations in schemes. Switching devices and contact connections
Alphanumeric designations in electrical circuits (GOST 2.710 - 81)
The letter codes of the elements are given in the table. Positional designations for elements (devices) are assigned within the product. Serial numbers to elements (devices) should be assigned, starting from one, within a group of elements that have the same letter code in accordance with the sequence of elements or devices on the diagram from top to bottom in the direction from left to right.
Positional designations are put down on the diagram next to the conditional graphic designation of elements or devices on the right side or above them. The numbers and letters included in the reference designation are of the same size.
| Singlebook- vein code |
Element view groups | Element Type Examples | Two-book vein code |
| A | Devices (general designation) | - | - |
| B | Converters of non-electric quantities to electrical (except generators and power supplies) or vice versa |
Selsyn - receiver | BE |
| Selsyn - sensor | BC | ||
| Thermal sensor | BK | ||
| Photocell | BL | ||
| Pressure meter | BP | ||
| Tachogenerator | BR | ||
| Speed sensor | BV | ||
| C | Capacitors | - | - |
| D | Integrated circuits, microassemblies |
Integrated circuit, analog | DA |
| Integrated circuit, digital, logical element |
DD | ||
| delay device | DT | ||
| Information storage device | D.S. | ||
| E | Elements are different | A heating element | EK |
| Lighting lamp | EL | ||
| F | Dischargers, fuses, protective devices |
Discrete element of protection by instantaneous current |
FA |
| Discrete element of protection by inertial current |
FP | ||
| Discrete element of protection by voltage |
FV | ||
| Fuse | FU | ||
| G | Generators, power supplies | Battery | GB |
| H | Indicator and signal elements | Sound alarm device | HA |
| Symbolic indicator | HG | ||
| Light signaling device | HL | ||
| K | Relays, contactors, starters | Relay index | KH |
| Current relay | KA | ||
| Relay electrothermal | KK | ||
| Contactor, magnetic starter | KM | ||
| Relay polarized | KP | ||
| Time relay | KT | ||
| Voltage relay | KV | ||
| L | Inductors, chokes | choke fluorescent lighting | LL |
| M | Engines | - | - |
| P | Instruments, measuring equipment | Ammeter | PA |
| Pulse counter | PC | ||
| Frequency meter | PF | ||
| Reactive Energy Meter | PK | ||
| Active energy meter | PI | ||
| Ohmmeter | PR | ||
| Recording device | PS | ||
| Time meter, clock | PT | ||
| Voltmeter | PV | ||
| Wattmeter | PW | ||
| Q | Switches and disconnectors in power circuits | Automatic switch | QF |
| Disconnector | QS | ||
| R | Resistors | Thermistor | RK |
| Potentiometer | RP | ||
| Measuring shunt | RS | ||
| Varistor | EN | ||
| S | Switching devices in control, signaling and measuring circuits Note. The designation is used for devices that do not have contacts in power circuits |
Breaker or switch | SA |
| push button switch | SB | ||
| Automatic switch | SF | ||
| Switches triggered by various influences: -from the level |
SL | ||
| - from pressure | SP | ||
| -from position | SQ | ||
| - from the frequency of rotation | SR | ||
| - from temperature | SK | ||
| T | Transformers, autotransformers | Current transformer | TA |
| voltage transformer | TV | ||
| Stabilizer | TS | ||
| U | Electrical to electrical converters | frequency converter, inverter, rectifier |
USD |
| V | Electrovacuum and semiconductor devices | diode, zener diode | VD |
| Electrovacuum devices | VL | ||
| Transistor | VT | ||
| Thyristor | VS | ||
| X | Contact connections | current collector | XA |
| Pin | XP | ||
| Nest | XS | ||
| Collapsible connections | XT | ||
| Y | Mechanical devices with electromagnetic drive | Electromagnet | YA |
| Brake with electromagnetic driven |
YB | ||
| electromagnetic plate | YH |
CONDITIONAL GRAPHIC DESIGNATIONS IN SCHEMES. ELECTRIC MACHINES (GOST 2.722-68)
1. Three methods are established for constructing conventional graphic symbols for electrical machines:
- simplified one-line;
- simplified multi-line (form I);
- deployed (form II).
2. In simplified single-line designations of electrical machines, the stator and rotor windings are depicted as circles. The conclusions of the stator and rotor windings are shown in one line indicating the number of conclusions on it in accordance with the requirements of GOST 2.751-73.
3. In simplified multi-line designations, the stator and rotor windings are depicted similarly to simplified single-line designations, showing the leads of the stator and rotor windings (Fig. 1).
4. In expanded notation, the stator windings are depicted as chains of semicircles, and the rotor windings are depicted as a circle (and vice versa).
The mutual arrangement of the windings is depicted:
- a) in AC and universal machines - with (Fig. 2) or without (Fig. 3) phase shift;
- b) in DC machines - taking into account (Fig. 4) or without taking into account (Fig. 5) the direction of the magnetic field created by the winding.
5. In examples of conventional graphic symbols for AC machines and universal machines, symbols are given, as a rule, reflecting the phase shift in the winding, in examples of DC machines, as a rule, without taking into account the direction of the magnetic field.
6. The conclusions of the stator and rotor windings in the designations of machines of all types can be depicted from any side.
7. The designations of the elements of electrical machines are given in table. one.
SYMBOLS IN ELECTRICAL DIAGRAM ACCORDING TO GOST 7624-55
In the Soviet Union, in 1955, GOST 7624-55 was adopted for a number of designations in radio engineering schemes, which was canceled in 1964. Considering that schemes with old designations are still preserved, below are the main symbols from GOST 7624-55. Symbols for wires, individual elements of machines and devices (GOST 7624-55)
SYMBOLS. ELECTRIC METERING DEVICES (GOST 2.729-68)
The table shows some of the conventional graphic designations of electrical measuring instruments.
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