Types and types of electrical circuits and their purpose

A diagram is a graphic design document that shows the component parts of a product and the relationships between them in the form of conventional images and notations.

The diagrams are included in the set of project documentation and contain, together with other documents, the necessary data for the design, manufacture, installation, adjustment and operation of the product.

Schemes are intended:

• at the design stage — to determine the structure of the future product,
• at the production stage — to familiarize yourself with the design of the product, the development of technological processes for production, assembly and control of the product,
• during the operation phase — to identify faults, repair and maintain the product.

In accordance with the State Standard of Russia GOST 2.701-84, the schemes and their letter designations, depending on the types of elements and connections that make up the product (installation), are divided into the types presented in Table 1.

Table 1. Types of schemes

No. Scheme type Designation 1 electric NS 2 hydraulic G 3 pneumatic NS 4 gas (except pneumatic) x 5 kinematic YES 6 vacuum V 7 optical L 8 energetic R 9 division E 10 combined With

For a product that includes elements of different types of circuits, several diagrams of the corresponding types are developed, for example, an electrical schematic diagram and a hydraulic schematic diagram, or one combined diagram containing elements and connections of different types.

A chart of one type is allowed to display elements of a chart of another type that directly affect the operation of a chart of that type. It is also allowed to indicate on the diagram elements and devices that are not included in the product (installation), on which the diagram is drawn up, but are necessary to explain the principles of operation of the product (installation).

The graphic designations of such elements and devices are separated on the diagram by dashed lines, equal in thickness to the communication lines, and labels are placed indicating the location of these elements, as well as the necessary explanatory information.

Depending on the main purpose, the circuits are divided into types presented in Table 2. Each type of circuit is assigned a numerical designation.

All schemes are divided by type into electrical, hydraulic, pneumatic, kinematic and combined... Electricians mainly use electrical circuits. However, depending on the nature of the electrical installation (various drives, lines), in addition to electrical circuits, other types of circuits are sometimes made, for example, kinematic ones.If they serve to better understand the electrical circuit, then it is permissible to depict both types of circuits in one drawing.

The main working diagrams and drawings are: structural, functional and schematic diagrams of automation, external electrical and pipe wiring diagrams, general views of boards and consoles, electrical diagrams of boards and consoles, plans for the location of automation equipment and electrical and pipe wiring (route drawings).

Diagrams are divided into seven types: structural, functional, principle, connections (installation), connections (external connection diagrams), general and location.

Table 2. Types of electrical circuits

Scheme type Designation structural 1 functional 2 principle (complete) 3 connections (assembly) 4 connectivity 5 general 6 location 7 united 0

The full schema name is determined by the schema type and type. For example, electrical schematic diagram — E3, electrohydropneumokinematic schematic diagram (combined) — SZ; circuit diagram and connections (combined) — EC.

In addition to diagrams or instead of diagrams (in cases established by the rules for the implementation of specific types of diagrams), tables are issued in the form of independent documents that contain information on the location of devices, connections, connection points and other information. Such documents are assigned a code consisting of the letter T and the code of the relevant scheme. For example, the connection table code to the TE4 wiring diagram. Connection tables are written in the specification after or instead of the circuits to which they are issued.

Below we will consider schematic diagrams, connections and connections such as those that have received the widest application in the electrical equipment of industrial enterprises.

Schematic diagrams are practically divided into two types. One of them shows the primary (power) networks and, as a rule, is performed in a single-line image.

Depending on the purpose of the circuit in the drawing, they depict:

a) only the power circuit (power supplies and their output lines);

b) only distribution network circuits (electrical receivers, lines feeding them);

c) for small objects of the schematic diagram, the images of the power and distribution network diagrams are combined.

Another type of wiring diagrams reflect drive control, line, protection, interlocks, alarms. Before the introduction of ESKD, such schemes were called elementary or advanced.

Schematic diagrams of this type are performed each on a separate drawing, or several of them are shown on one drawing if it helps to read the diagram and slightly increases the dimensions of the drawing. For example, control schemes and general automation or protection, measurement and control, etc. are combined in one drawing.

A complete schematic diagram contains those elements and electrical connections between them that give a complete idea of ​​​​the principle of operation of an electrical installation, allowing you to read its diagram.

In contrast to a complete schematic diagram, individual product schematic diagrams are executed. A schematic diagram of the product, as a rule, is part of a complete circuit diagram, the so-called copy of it.

For example, the schematic diagram of the control unit shows only those elements that are installed in the control unit. From this diagram, of course, it is impossible to get an idea of ​​\u200b\u200bthe operation of the electrical installation as a whole, and in this sense the schematic diagrams of the products cannot be read. However, from the schematic diagram of the product, it is quite clear what is installed in the product and what connections need to be made in it, that is, it becomes clear exactly what the manufacturer of the product needs.

Connection schemes (installation) are intended for making electrical connections on them within complete devices, electrical structures, that is, connections of devices to each other, devices with riser rails, etc. That is, connection of its parts. An example of such a scheme is the connection scheme of the actuator valve.

Connection diagrams (external connection diagrams) serve to connect electrical equipment to each other with wires, cables, and sometimes buses. This electrical equipment is assumed to be geographically "dispersed". The connection scheme is implemented, for example, for connections between different complete devices, for connections between complete devices with free-standing electrical receivers and devices, for connecting free-standing devices to each other, etc.

Connection diagrams also include connections between different mounting blocks that are part of a single unit, for example connections within a control panel over 4 m long (the maximum size of the mounting block within which the manufacturer makes all connections is 4 m ).