JB/T 2740-1996 Drawing of electrical diagrams, diagrams and tables for electrical equipment of industrial machinery
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T2740—1996
Electrical Equipment of Industrial Machinery
Drawing of Electrical Diagrams, Diagrams and Tables
Published on April 22, 1996
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1996
JB/T2740—1996
1 Subject Content and Scope of Application
2 Reference Standards
3 Terminology
4 General Rules
5 Four-segment Notation Method for Project Code
Circuit Diagram
System Diagram or Block Diagram
8 Wiring Diagram and Wiring Table
Electrical component installation drawing
Installation drawing of electrical equipment for industrial machinery (installation drawing) 11
List of electrical equipment components
Additional instructions
Specific requirements for various documents
Appendix A: Examples of electrical diagrams, diagrams and tables and their explanations (supplements) Appendix B High-level codes and location codes and their application (reference) Appendix C
Drawing of ladder diagrams (reference)
Machinery Industry Standard of the People's Republic of China
Electrical equipment for industrial machinery
Drawing of electrical diagrams, diagrams and tables
This standard is formulated with reference to the following International Electrotechnical Commission (IEC) standards. IEC1082-1:1991 Preparation of electrical technical documents - Part 1: General requirements JB/T2740-1996
Replaces JB2740-85
IEC1082-2: Preparation of electrical technical documents - Part 2: Schematic diagrams arranged by function (under preparation IEC1082-3: Preparation of electrical technical documents - Part 3: Connection diagrams, tables and catalogs (under preparation) IEC750:1983 Item codes in electrical technology 1 Subject content and scope of application
This standard specifies the method for drawing electrical diagrams, diagrams and tables of electrical equipment of industrial machinery This standard applies to electrical diagrams, diagrams and tables of electrical equipment of industrial machinery such as metal cutting machine tools, woodworking machine tools, electric machining machine tools, casting and forging machinery Drawing of tables.
2 Reference standards
GB4728
GB4884
GB/T5226.1
GB7159
GB10609.1
JB/T2739
3 Terms
3.1 Definition of drawings and tables
Sheet size and format of mechanical drawings
Fonts for mechanical drawings
Graphic symbols for electrical drawings
Marking of insulated wires
Industrial machinery and electrical equipment Part 1: General technical conditions General rules for electrical drawings
General rules for the formulation of text symbols in electrical technology Title bar of technical drawings
Graphic symbols for industrial machinery and electrical drawings|| tt||It is a general term for various forms of expression using diagrams, and can also be defined as a technical document that uses diagrams to represent information. 3.1.2 Simple diagram
A diagram that uses graphic symbols, annotated frames or simplified shapes to represent the relationship and connection between the components of a system or equipment. When it does not cause confusion, a simple diagram can also be referred to as a diagram. 3.1.3 Table
A form of expression that arranges data and other content vertically and horizontally to illustrate the relationship or connection between the components of a system, complete set of equipment or equipment, or to provide working parameters. A table can also be referred to as a table. Tables can be used as a supplement to diagrams, or they can be used to replace certain diagrams.
Approved by the Ministry of Machinery Industry on April 22, 1996
199 %-07-01 Implementation
3.1.4 System diagram or block diagram
JB/T2740-1996
A diagram that uses symbols or annotated boxes to roughly represent the basic components, interrelationships and main features of a system or subsystem. 3.1.5 Logic diagram
A diagram drawn mainly with binary logic unit graphic symbols. A logic diagram that only represents functions without involving their implementation methods is called a pure logic diagram.
3.1.6 Circuit diagram
A diagram that uses graphic symbols and arranges them in working order to show in detail all the basic components and connection relationships of a circuit, equipment or complete set of equipment without considering their actual positions. The purpose is to facilitate detailed understanding of the working principle, analysis and calculation of circuit characteristics. 3.1.7 Equipment component table (equipment component list) A table that lists the components and corresponding data in a complete set of equipment, equipment and devices. Its purpose is to indicate the name, model, specification and quantity of each component.
3.1.8 Interconnection diagram or interconnection table
A wiring diagram or table showing the connection relationship between different structural units of a complete set of equipment or equipment, and marking the data required for external wiring.
3.1.9 Unit wiring diagram or unit wiring table
A wiring diagram or table showing the connection relationship within a structural unit in a complete set of equipment or equipment. 3.1.10 Terminal wiring diagram or terminal wiring table A wiring diagram or table showing the terminals of a complete set of equipment or equipment and the external wiring connected to the terminals (including internal wiring when necessary).
3.1.11 Cable diagram
A diagram (table) that provides information about the cable, such as the identification of the conductors, the location of the terminal connections, and, when necessary, the characteristics, routes and functions. 3.1.12 Location diagram or location diagram
A diagram or a diagram showing the relative positions of the various items in a complete set of equipment or equipment. 3.1.13 Machine tool electrical equipment installation drawing (installation drawing) A drawing showing the layout of each unit of the machine tool electrical equipment and the data required for installation work. 3.1.14 Ladder diagram
A collection of graphics that describes logical operations or functional operations that are executed sequentially in accordance with specified graphic symbols to achieve the control requirements of the machine tool. 3.1.15 Flowchart
A sequence diagram that expresses the causal relationship or operation steps of the operation of a numerical control system, programmable controller or servo system in words or statements. 3.1.16 Statement list
A symbol for instructions for a numerical control system or programmable controller to perform a specific logical operation or functional operation. 3.1.17 Diagram
Used to represent:
a. A schematic diagram of the relationship between different operations; b. A schematic diagram of the relationship between each operation and time; c. A schematic diagram of the relationship between each operation and physical quantity d. A schematic diagram of the relationship between the status of each item. 3.2 Representation
3.2.1 Multi-line representation
JB/T2740-1996
A method in which each connecting line or conductor is represented by a separate line on the schematic diagram. 3.2.2 Single-line representation
A method in which two or more connecting lines or conductors are represented by only one line on the schematic diagram. 3.2.3 Connection representation (centralized representation) A method in which the graphic symbols of a component of a project in a device or complete set of equipment are drawn together on the schematic diagram. 3.2.4 Semi-connection representation (semi-centralized representation) A method in which the graphic symbols of some components of a project are arranged separately on the schematic diagram in order to make the circuit layout of the equipment and device clear and easy to identify, and the relationship between them is represented by mechanical connection line symbols. 3.2.5 Separate representation
A method in which the graphic symbols of the components of a project are arranged separately on the schematic diagram in order to make the circuit layout of the equipment and device clear and easy to identify, and the relationship between them is represented by only the project code. 3.3 Item Code Terminology
3.3.1 Basic Parts
Components that cannot be disassembled and lose their functions when disassembled. Such as integrated circuits, resistors, electromagnetic coils, etc. 3.3.2 Components
Parts of an assembly consisting of two or more basic parts. It can be replaced as a whole or one or more basic parts can be replaced individually. For example, overcurrent protectors, filter network units, operating panels, etc. 3.3.3 Assembly
A combination of several basic parts and (or) several components installed together to complete a specific function. For example, engine blocks, audio amplifiers, power supply devices, etc.
3.3.4 Items
Refers to the general term for basic parts, components, equipment, functional units, etc., which are usually represented by a graphic symbol on the diagram. For example, resistors, relays, generators, amplifiers, power supply devices and switch devices, etc., can all be regarded as an item. 3.3.5 High-level code
The code of any higher-level (for the project with a code) project in the system or equipment. For example, the main transmission device of a machine tool is a project composed of the main motor, starter and its control equipment, which is represented by a high-level code. 3.3.6 Position code
Refers to the code of the actual position of the project in the component, equipment, or system. 3.3.7 Category code
A code mainly used to identify the type of item. The type of item has nothing to do with the function of the item in the circuit. For example, all kinds of resistors can be regarded as a type of item. For some components, they can be classified according to their role in the circuit when they are used. For example, different letter codes for the type of item can be assigned according to the different functions of the switch in the power circuit (as a circuit breaker) or the control circuit (as a selector). 3.3.8 Terminal code
A code for electrical conductive parts that are electrically connected to external circuits. 3.3.9 Project code
A specific code used to identify the type of item in drawings, charts, tables and other technical documents and equipment, and to provide information such as the hierarchical relationship and actual location of the item
3.3.10 Code segment
JB/T2740-1996
A part of the complete project code with relevant information. The complete project code is divided into four segments: high-level code, position code, category code and terminal code.
3.3.11 Prefix symbols
Symbols used to distinguish between different code segments, including equal to "", plus sign "+", minus sign "_" and colon ":". 4 General rules
4.1 General provisions
4.1.1 Drawings
4. 1. 1. 1
The drawing format size and its code are shown in Table 1.
The format specified in Table 2 should be used.
If extended drawings are required,
841×1189
594X841
420×594
297X420
210×297
420×891
420×1189
297×630
297×841
297×1051
If the formats listed in Tables 1 and 2 still cannot meet the needs, the format can be increased according to the provisions of GB4457.1. 4.1.1.2
The orientation of the title bar, drawing frame and drawing partition shall comply with the relevant provisions of GB4457.1. Except for the size, position and content of the title bar in the "circuit diagram" which are determined by each enterprise, the rest shall comply with the relevant provisions of GB10609.1. 4.1.1.3 Selection principles
On the premise of ensuring the compact, clear and easy-to-use layout of the drawing, the selection of the drawing format shall comply with the provisions of 4.1.1.1 and shall consider:
The scale and complexity of the design object; a.
b. The level of detail of the data determined by the type of drawing; c. Try to use a smaller format;
d. Facilitate the binding and management of the drawings;
e. The requirements for copying and microfilming;
f. The requirements for computer-aided design.
When the drawing is drawn on several sheets, in order to facilitate binding, the format of all drawings should generally be the same. 4.1.1.4 NumberingbZxz.net
JB/T2740-1996
All drawings should be numbered in the title bar. For a drawing with multiple sheets, each drawing should be numbered in sequence. The numbering can be done according to the method specified in GB6988.2. 4.1.1.5 Drawing Partitioning
In order to facilitate the determination of the content, supplementary changes and the location of each component on the drawing, it can be divided into different sections on drawings of various sheets, see Figure 1
The numbering should be even. The length of each section should be equidistant, generally not less than 25mm and not more than 75mm. Each section is numbered in Latin letters in the vertical direction and Arabic numerals in the horizontal direction. The numbering order should start from the upper left corner opposite to the title bar. The starting point of each section is counted from the intersection of the inner lines. The section code is represented by the letters and numbers of the area, with the letters in front and the numbers in the back, such as B3 and C5. In a drawing with several sheets, the drawing code between sheets should not be continuous. A
4.1.2 Drawing lines
4.1.2.1 Type
In order to make the drawings clear, the meaning clear, and the drawing convenient, according to the provisions of GB6988.2, the drawing line types shown in Table 3 should be used. Table 3
Line name
Dash-dot line
Double dash-dot line
Line type
4.1.2.2 Width
Basic line, line for main content of simplified diagram, visible contour line, auxiliary line for visible wire, shielding line, mechanical connection line, invisible outline line, invisible wire, dividing line for planned extension content, structural frame line, functional frame line, grouping frame line, auxiliary frame line
Line width should generally be selected from the following series: 0.25, 0.35, 0.5, 0.7, 1.0, 1.4mm. Usually only two widths of lines are selected. The width of thick lines is twice that of thin lines. However, in some drawings, more than two widths of lines may be required. In this case, the line width should increase in multiples of 2. 4.1.2.3 Spacing
JB/T2740-1996
Taking into account the needs of reproduction and microfilming, it is recommended that the minimum spacing between parallel lines should be no less than twice the width of the thick line. If two parallel lines are of equal width, the distance between the centers of the two lines should be at least three times the line width. For parallel connecting lines in a simplified diagram, the distance between the centers should be at least equal to the character height. For connecting lines with additional information (such as signal codes), this distance should be at least twice the character height. For parallel connecting lines in a simplified diagram, the distance between the centers should be at least equal to the character height. For connecting lines with additional information (such as signal codes), this distance should be at least twice the character height. 4.1.3 Font
Fonts shall comply with the provisions of GB4457.3.
In order to meet the requirements of microfilming, the recommended minimum font height is shown in Table 4. Table 4
Basic drawing format
Minimum font height mm
Except for the border, all letters in the drawing should be readable from the bottom or right side of the drawing. 4.1.4 Arrows and guide lines
4.1.4.1 Arrows
The arrows on signal lines and connecting lines should be open, as shown in Figure 2. The arrows on guide lines should be solid, as shown in Figure 3 (b). Figure 2
4.1.4.2 Guide lines
Guide lines should be thin solid lines pointing to the annotated area, and the following marks should be added at their ends: if the end is within the outline line, add a black dot, see Figure 3a; if the end is on the outline line, add a solid arrow, see Figure 3b; if the end is on the connecting line, add a short slash, see Figure 3c. a
4.1.5 Scale
If it is necessary to draw in proportion, such as a location diagram, you can choose from the following scale series: 110, 1:20, 1:50, 1:100, 1:200, 1:500.6
JB/T2740-1996
When other scales are required, they should be selected according to relevant national standards. 4.2 Layout of schematic diagrams
Simple diagrams should be drawn with reasonable layout, uniform arrangement, clear drawings, and easy to read. The lines representing wires, signal paths, connecting lines, etc. should be straight lines with the least crosses and bends. They can be arranged horizontally or vertically, but in order to connect the components into a symmetrical layout, oblique cross lines can also be used. Components can also be arranged according to function and arranged in working order as much as possible. For schematic diagrams with clear cause-effect order, especially circuit diagrams and logic diagrams, the layout order should be from left to right or from top to bottom. If the above regulations are not met and the flow direction is not obvious, an open arrow should be drawn on the information line. The open arrow should not touch other symbols (such as limiting symbols). In a closed circuit, the signal flow direction of the forward path should be from left to right or from top to bottom, and the direction of the feedback path is the opposite. The lead-in or lead-out lines of the drawing are best drawn near the border of the drawing. In a simple diagram describing a control system, the functional symbol group that constitutes the controlling system should be arranged to the left or above the functional symbol group of the controlled system.
In a simple diagram that reflects the actual layout, symbols should be arranged in groups and show the actual relative positions of the corresponding components. 4.3 Graphic symbols
4.3.1 Application of symbols
Graphic symbols must be combined in accordance with the symbol usage or principles specified in JB/T2739. For the contents beyond JB/T2739, the contents of GB4728 can be consulted. If the required symbols have not been standardized, they should be explained in the figure with annotations or instructions. 4.3.2 Selection of symbols
When JB/T2739 gives several forms, the selection of symbols should follow the following principles: a. Use the preferred form as much as possible:
b. Under the premise of meeting the needs, try to use the simplest form; c. In the same drawing number, the same form of symbols should be used. For simple diagrams with relatively simple contents (such as system diagrams), especially for simple diagrams drawn by single-line representation, in general, general symbols or simplified symbols can be used. The connection points of connecting lines are represented by small dots, and small dots can be used without causing misunderstanding. 4.3.3. Symbol status
On the circuit diagram, the status of each component should be drawn as the status before power is turned on, the binary logic component should be drawn as the "zero" status, and the operating switch should be drawn as the status before the machine tool starts working. a: The components subjected to external force at the starting position of the machine tool must be drawn as the status under the external force. At this time, if the contact is closed, for the circuit arranged in the vertical direction, it must be drawn on the left, and the disconnected contact must be drawn on the right. The graphic symbols and mechanical connections of the operating components that act on it must be drawn. The direction of action and the direction of contact movement must be consistent. For the horizontally arranged circuit diagram, it is drawn in the form of bottom closed and top open: b. Except for the contacts that have been subjected to external force at the starting position of the machine tool, the remaining contacts are generally drawn in the form of left open and right closed or top closed and bottom open. For simple diagrams with more detailed content, if general symbols cannot meet the requirements, they should be enriched according to relevant requirements. For circuit diagrams, complete graphic symbols must be used. 4.3.4 Symbol size
In most cases, the meaning of a symbol is determined by its form, and the size of the symbol and the thickness of the line generally do not affect the meaning of the symbol. In the following cases, graphic symbols are allowed to be enlarged or reduced: a. When one symbol defines another symbol, the defining graphic symbol is reduced and the defined one is enlarged, but the proportions must be coordinated and appropriate;
b. In order to highlight a certain part, the highlighted part is allowed to be enlarged. For example, power leads and main power lines can be drawn with thick lines: c. In order to facilitate supplementary information or increase the number of inputs and outputs, some graphic symbols are allowed to be enlarged. 7
JB/T2740-1996
The minimum size of a symbol should comply with the rules for line width, line spacing, letter marking, etc. 4.3.5 Symbol orientation
The orientation of most symbols is arbitrary. In order to avoid bending or crossing of wires, the symbol can be rotated or drawn in its mirror state without causing misunderstanding. Box symbols, binary logic unit symbols and analog unit symbols, including letters, qualifiers, graphics or input/output marks, should be arranged so that they can be read from the bottom or right side of the diagram. Therefore, if the signal flow is:
from left to right, the symbols should be arranged in the form shown in JB/T2739: - from bottom to top, the symbols should be rotated 90° counterclockwise; - from right to left, a new symbol should be specified to indicate that the inputs and their marks are on the right, and the outputs and their marks are on the left: - from top to bottom, a new symbol should be specified to show that the inputs and their marks are on the right, and the outputs and their marks are on the left, and the symbols should be rotated 90° counterclockwise.
4.3.6 Representation of terminals
The graphic symbols in JB/T2739 generally do not have terminal symbols. In some special cases, if the terminal symbol is part of the graphic symbol, the terminal symbol must be drawn.
4.3.7 Representation of leads
Leads can be in different directions without changing the meaning of symbols. For example, transformers are represented by the symbol shown in Figure 4a in both GB4728 and JB/T2739. The method shown in Figure 4b is also allowed. a
However, in some cases, when the position of the line symbol affects the meaning of the symbol, it must be drawn according to the method specified in GB4728. For example, resistors, see Figure 5a. Relay coils, see Figure 5b. Otherwise, once the position of these leads is changed, the meaning of the symbol will also change.
4.4 Connecting lines
Connecting lines should be solid lines, and the content planned to be extended should be dotted lines. b
A connecting line should not change direction at the intersection with another connecting line, nor should it pass through the connection point of other connecting lines. If there are multiple parallel connecting lines, they should be grouped by function for ease of viewing. When not grouped by function, they can be grouped arbitrarily, with no more than three lines in each group. The distance between groups should be greater than the distance between lines. 4.4.1 Marking of connecting lines
Whether adding signal names or other marks on single lines or groups of connecting lines to indicate their functions or directions, their identification marks should generally be marked above the connecting lines (horizontally arranged) or to the left (vertically arranged), and the connecting lines can also be marked without marking. 8
4.4.2 Interrupted lines
JB/T2740-1996
When the connecting lines crossing the drawing are long or cross dense areas of the graphics, the connecting lines are allowed to be interrupted and corresponding marks are added at the interruption. Line groups going to the same direction can also be interrupted, and appropriate marks are added at the end of the line group. Connecting lines connected to another drawing should be interrupted, and the drawing number, sheet number, map partition code and other marks should be noted at the interruption. For example, Figure 6.
If there are several interrupted lines on the same drawing, they must be distinguished by different marks, represented by different letters, or distinguished by the functional marks of the connecting lines. 15/H4-
4.4.3 Single-line representation
The main purpose of single-line representation is to avoid too many parallel lines. Figure 6
a. In a group of lines, when each connecting line is in different positions at both ends, it should be marked with the same number (such as line A at one end in the 1st position and the other end in the 3rd position) as shown in Figure 7.
b. When a single conductor merges into a group of connecting lines represented by a single line, the method shown in Figure 8 should be used to represent it. This method usually requires marking symbols at the end of each connecting line, except for obvious ones. The junction should be represented by a slash, and its direction should make it easy for the viewer to identify the direction in which the connecting line enters or leaves the aggregate line. As shown in Figure 8.
The line that intersects with any line in the bundle does not need to be slanted. Figure 8
C: When multiple conductors or connecting lines are represented by a single line, the number of outgoing lines should be indicated if necessary. As shown in Figure 9. 9
4.4.4 Enclosure
JB/T2740-1996
Simplified form of 1 conductor
Simplified form of 5 conductors
When it is necessary to show in the drawing that a certain part represents a functional unit, a structural unit or a project group (such as an electrical unit, a relay device), it can be represented by a dotted line enclosure. In order to make the drawing clear, the shape of the enclosure can be irregular. The enclosure line should not intersect with the component symbols, except for the plug, socket and terminal symbols. They can be on the enclosure line, or inside the enclosure line, or can be omitted. The symbols inside or on the enclosure line belong to the components of the unit. When a unit is represented by an enclosure, if a mark for more detailed information is given in the enclosure, the circuit inside it can be represented in a simplified form.
If the figure inside the enclosure representing a unit contains component symbols that do not belong to the unit, these symbols must be surrounded by double dotted lines and marked with codes or annotations. See Figure 10. When the shield or grounding surrounds the entire structural unit, the boundary line (dash-dot line) should be omitted. 0
Key points not covered in one 06
4.4.5 Simplified method
4.4.5.1 Terminals
Multiple terminals in a component can be represented by one terminal symbol. Especially in system diagrams, terminal codes can be separated by commas. If the terminals are numbered consecutively and will not cause confusion, only the first and last codes can be represented, separated by dots. As shown in Figure 11. &
The same symbols in a group
The same symbols in a group can be represented by one symbol, and a slash is added to indicate the number of the same symbols. Especially for square 10In order to facilitate the supplement of information or increase the number of inputs and outputs, some graphic symbols are allowed to be enlarged. 7
JB/T2740-1996
The minimum size of the symbol shall comply with the rules for line width, line spacing, letter marking, etc. 4.3.5 Orientation of symbols
The orientation of most symbols is arbitrary. In order to avoid bending or crossing of wires, the symbol can be rotated or drawn in its mirror state without causing misunderstanding. Box symbols, binary logic unit symbols and analog unit symbols, including letters, qualifiers, graphics or input/output marks, should be arranged so that they can be read from the bottom or right side of the drawing. Therefore, if the signal flow is:
From left to right, the symbols should be arranged in the form shown in JB/T2739: - From bottom to top, the symbols should be rotated 90° counterclockwise; - From right to left, a new symbol should be specified to indicate that the input and their marks are on the right, and the output and their marks are on the left: - From top to bottom, a new symbol should be specified to show that the input and their marks are on the right, and the output and their marks are on the left, and the symbol should be rotated 90° counterclockwise.
4.3.6 Representation of terminals
The graphic symbols in JB/T2739 generally do not have terminal symbols. In some special cases, if the terminal symbol is part of the graphic symbol, the terminal symbol must be drawn.
4.3.7 Representation of leads
Under the principle of not changing the meaning of the symbol, the leads can take different directions. For example, transformers are represented by the symbols shown in Figure 4a in both GB4728 and JB/T2739. The method shown in Figure 4b is also allowed. a
However, in some cases, when the position of the line symbol affects the meaning of the symbol, it must be drawn according to the method specified in GB4728. For example, resistors, see Figure 5a. Relay coils, see Figure 5b. Otherwise, once the position of these leads changes, the meaning of the symbol will also change.
4.4 Connecting lines
Connecting lines should be solid lines, and the content planned to be extended should be dotted lines. b
A connecting line should not change direction at the intersection with another connecting line, nor should it pass through the connection point of other connecting lines. If there are multiple parallel connecting lines, they should be grouped according to function for ease of viewing. When not grouped according to function, they can be grouped arbitrarily, with no more than three lines in each group. The distance between groups should be greater than the distance between lines. 4.4.1 Marking of connecting lines
Whether adding signal names or other marks to single lines or groups of connecting lines to indicate their functions or their destinations, their identification marks should generally be marked above the connecting line (horizontally arranged) or to the left (vertically arranged), and the connecting line markings can also be disconnected. 8
4.4.2 Interrupted lines
JB/T2740-1996
When the connecting line that crosses the drawing is long or crosses a densely-populated area, it is allowed to interrupt the connecting line and add corresponding marks at the interruption point. Lines that go to the same group can also be interrupted, and appropriate marks should be added at the end of the line group. The connecting line connected to another drawing should be interrupted, and the drawing number, sheet number, map division code and other marks should be noted at the interruption point. For example, Figure 6.
If there are several interrupted lines on the same drawing, they must be distinguished by different marks, represented by different letters, or by the functional marks of the connecting lines. 15/H4-
4.4.3 Single-line representation
The main purpose of the single-line representation is to avoid too many parallel lines. Figure 6
a. In a group of wires, when each connecting wire is in different positions at both ends, it should be marked with the same number (such as one end of line A is in the 1st position and the other end is in the 3rd position) as shown in Figure 7. Figure 6
b. When a single conductor merges into a group of connecting wires represented by a single line, it should be represented by the method shown in Figure 8. This method usually requires marking symbols at the end of each connecting wire, except for obvious ones. The junction should be represented by a slash, and its direction should make it easy for the viewer to identify the direction in which the connecting wire enters or leaves the aggregate line. As shown in Figure 8. Figure 8
Lines that intersect with any line in the bundle do not need to be tilted. Figure 8
C: When multiple conductors or connecting wires are represented by a single line, the number of outgoing wires should be indicated if necessary. As shown in Figure 9. 9
4.4.4 Enclosure
JB/T2740-1996
Simplified form of 1 conductor
Simplified form of 5 conductors
When it is necessary to show in the drawing that a certain part represents a functional unit, a structural unit or a project group (such as an electrical unit, a relay device), it can be represented by a dotted line enclosure. In order to make the drawing clear, the shape of the enclosure can be irregular. The enclosure line should not intersect with the component symbols, except for the plug, socket and terminal symbols. They can be on the enclosure line, or inside the enclosure line, or can be omitted. The symbols inside or on the enclosure line belong to the components of the unit. When a unit is represented by an enclosure, if a mark for more detailed information is given in the enclosure, the circuit inside it can be represented in a simplified form.
If the figure inside the enclosure representing a unit contains component symbols that do not belong to the unit, these symbols must be surrounded by double dotted lines and marked with codes or annotations. See Figure 10. When the shield or grounding surrounds the entire structural unit, the boundary line (dash-dot line) should be omitted. 0
Key points not covered in one 06
4.4.5 Simplified method
4.4.5.1 Terminals
Multiple terminals in a component can be represented by one terminal symbol. Especially in system diagrams, terminal codes can be separated by commas. If the terminals are numbered consecutively and will not cause confusion, only the first and last codes can be represented, separated by dots. As shown in Figure 11. &
The same symbols in a group
The same symbols in a group can be represented by one symbol, and a slash is added to indicate the number of the same symbols. Especially for square 10In order to facilitate the supplement of information or increase the number of inputs and outputs, some graphic symbols are allowed to be enlarged. 7
JB/T2740-1996
The minimum size of the symbol shall comply with the rules for line width, line spacing, letter marking, etc. 4.3.5 Orientation of symbols
The orientation of most symbols is arbitrary. In order to avoid bending or crossing of wires, the symbol can be rotated or drawn in its mirror state without causing misunderstanding. Box symbols, binary logic unit symbols and analog unit symbols, including letters, qualifiers, graphics or input/output marks, should be arranged so that they can be read from the bottom or right side of the drawing. Therefore, if the signal flow is:
From left to right, the symbols should be arranged in the form shown in JB/T2739: - From bottom to top, the symbols should be rotated 90° counterclockwise; - From right to left, a new symbol should be specified to indicate that the input and their marks are on the right, and the output and their marks are on the left: - From top to bottom, a new symbol should be specified to show that the input and their marks are on the right, and the output and their marks are on the left, and the symbol should be rotated 90° counterclockwise.
4.3.6 Representation of terminals
The graphic symbols in JB/T2739 generally do not have terminal symbols. In some special cases, if the terminal symbol is part of the graphic symbol, the terminal symbol must be drawn.
4.3.7 Representation of leads
Under the principle of not changing the meaning of the symbol, the leads can take different directions. For example, transformers are represented by the symbols shown in Figure 4a in both GB4728 and JB/T2739. The method shown in Figure 4b is also allowed. a
However, in some cases, when the position of the line symbol affects the meaning of the symbol, it must be drawn according to the method specified in GB4728. For example, resistors, see Figure 5a. Relay coils, see Figure 5b. Otherwise, once the position of these leads changes, the meaning of the symbol will also change.
4.4 Connecting lines
Connecting lines should be solid lines, and the content planned to be extended should be dotted lines. b
A connecting line should not change direction at the intersection with another connecting line, nor should it pass through the connection point of other connecting lines. If there are multiple parallel connecting lines, they should be grouped according to function for ease of viewing. When not grouped according to function, they can be grouped arbitrarily, with no more than three lines in each group. The distance between groups should be greater than the distance between lines. 4.4.1 Marking of connecting lines
Whether adding signal names or other marks to single lines or groups of connecting lines to indicate their functions or their destinations, their identification marks should generally be marked above the connecting line (horizontally arranged) or to the left (vertically arranged), and the connecting line markings can also be disconnected. 8
4.4.2 Interrupted lines
JB/T2740-1996
When the connecting line that crosses the drawing is long or crosses a densely-populated area, it is allowed to interrupt the connecting line and add corresponding marks at the interruption point. Lines that go to the same group can also be interrupted, and appropriate marks should be added at the end of the line group. The connecting line connected to another drawing should be interrupted, and the drawing number, sheet number, map division code and other marks should be noted at the interruption point. For example, Figure 6.
If there are several interrupted lines on the same drawing, they must be distinguished by different marks, represented by different letters, or by the functional marks of the connecting lines. 15/H4-
4.4.3 Single-line representation
The main purpose of the single-line representation is to avoid too many parallel lines. Figure 6
a. In a group of wires, when each connecting wire is in different positions at both ends, it should be marked with the same number (such as one end of line A is in the 1st position and the other end is in the 3rd position) as shown in Figure 7. Figure 6
b. When a single conductor merges into a group of connecting wires represented by a single line, it should be represented by the method shown in Figure 8. This method usually requires marking symbols at the end of each connecting wire, except for obvious ones. The junction should be represented by a slash, and its direction should make it easy for the viewer to identify the direction in which the connecting wire enters or leaves the aggregate line. As shown in Figure 8. Figure 8
Lines that intersect with any line in the bundle do not need to be tilted. Figure 8
C: When multiple conductors or connecting wires are represented by a single line, the number of outgoing wires should be indicated if necessary. As shown in Figure 9. 9
4.4.4 Enclosure
JB/T2740-1996
Simplified form of 1 conductor
Simplified form of 5 conductors
When it is necessary to show in the drawing that a certain part represents a functional unit, a structural unit or a project group (such as an electrical unit, a relay device), it can be represented by a dotted line enclosure. In order to make the drawing clear, the shape of the enclosure can be irregular. The enclosure line should not intersect with the component symbols, except for the plug, socket and terminal symbols. They can be on the enclosure line, or inside the enclosure line, or can be omitted. The symbols inside or on the enclosure line belong to the components of the unit. When a unit is represented by an enclosure, if a mark for more detailed information is given in the enclosure, the circuit inside it can be represented in a simplified form.
If the figure inside the enclosure representing a unit contains component symbols that do not belong to the unit, these symbols must be surrounded by double dotted lines and marked with codes or annotations. See Figure 10. When the shield or grounding surrounds the entire structural unit, the boundary line (dash-dot line) should be omitted. 0
Key points not covered in one 06
4.4.5 Simplified method
4.4.5.1 Terminals
Multiple terminals in a component can be represented by one terminal symbol. Especially in system diagrams, terminal codes can be separated by commas. If the terminals are numbered consecutively and will not cause confusion, only the first and last codes can be represented, separated by dots. As shown in Figure 11. &
The same symbols in a group
The same symbols in a group can be represented by one symbol, and a slash is added to indicate the number of the same symbols. Especially for square 102 Interrupted lines
JB/T2740-1996
When the connecting line across the drawing is long or crosses a dense area of graphics, it is allowed to interrupt the connecting line and add corresponding marks at the interruption. Lines going to the same group can also be interrupted, and appropriate marks should be added at the end of the line group. Connecting lines connected to another drawing should be interrupted, and the drawing number, sheet number, map partition code and other marks should be noted at the interruption. For example, Figure 6.
If there are several interrupted lines on the same drawing, they must be distinguished by different marks, using different letters to represent them, or they can be distinguished by the functional marks of the connecting lines. 15/H4-
4.4.3 Single-line representation
The main purpose of the single-line representation is to avoid too many parallel lines. Figure 6
a, in a group of lines, when each connecting line is in different positions at both ends, it should be marked with the same number (such as line A at one end in the 1st position and the other end in the 3rd position) as shown in Figure 7. b. When a single conductor joins a group of connecting wires represented by a single line, the method shown in Figure 8 should be used. This method usually requires marking symbols at the end of each connecting wire, except for obvious ones. The junction should be represented by a slash line, and its direction should make it easy for the viewer to identify the direction in which the connecting wire enters or leaves the summary line. As shown in Figure 8. Lines that intersect with any line in the harness do not need to be tilted. Figure 8
C: When multiple conductors or connecting wires are represented by a single line, the number of outgoing wires shall be indicated if necessary. As shown in Figure 9. 9
4.4.4 Enclosure
JB/T2740-1996
Simplified form of 5 conductors
Simplified form of 5 conductors
When it is necessary to show that a certain part in the figure represents a functional unit, structural unit or item group (such as an electrical group, relay device), it can be represented by a dotted line enclosure. In order to make the drawing clear, the shape of the enclosure can be irregular. The frame line should not intersect with the component symbols, except for plug, socket and terminal symbols. They can be on the frame line, inside the frame line, or can be omitted. The symbols inside or on the frame line belong to the components of the unit. When a unit is represented by a frame, if a mark for more detailed information is given in the frame, the circuit inside it can be represented in a simplified form.
If the figure inside the frame representing a unit contains component symbols that do not belong to the unit, these symbols must be surrounded by double dotted lines and marked with codes or annotations. See Figure 10. When the shield or ground surrounds the entire structural unit, the boundary line (dotted line) should be omitted. 0
Key points not covered in 06
4.4.5 Simplified method
4.4.5.1 Terminals
Multiple terminals in a component can be represented by one terminal symbol. In particular, in system diagrams, terminal codes can be separated by commas. If the terminals are numbered consecutively and there is no confusion, only the first and last codes can be indicated, separated by a dot. As shown in Figure 11. &
Same symbols in a group
Same symbols in a group can be indicated by one symbol, and a slash is added to indicate the number of the same symbols. Especially for the square 102 Interrupted lines
JB/T2740-1996
When the connecting line across the drawing is long or crosses a dense area of graphics, it is allowed to interrupt the connecting line and add corresponding marks at the interruption. Lines going to the same group can also be interrupted, and appropriate marks should be added at the end of the line group. Connecting lines connected to another drawing should be interrupted, and the drawing number, sheet number, map partition code and other marks should be noted at the interruption. For example, Figure 6.
If there are several interrupted lines on the same drawing, they must be distinguished by different marks, using different letters to represent them, or they can be distinguished by the functional marks of the connecting lines. 15/H4-
4.4.3 Single-line representation
The main purpose of the single-line representation is to avoid too many parallel lines. Figure 6
a, in a group of lines, when each connecting line is in different positions at both ends, it should be marked with the same number (such as line A at one end in the 1st position and the other end in the 3rd position) as shown in Figure 7. b. When a single conductor joins a group of connecting wires represented by a single line, the method shown in Figure 8 should be used. This method usually requires marking symbols at the end of each connecting wire, except for obvious ones. The junction should be represented by a slash line, and its direction should make it easy for the viewer to identify the direction in which the connecting wire enters or leaves the summary line. As shown in Figure 8. Lines that intersect with any line in the harness do not need to be tilted. Figure 8
C: When multiple conductors or connecting wires are represented by a single line, the number of outgoing wires shall be indicated if necessary. As shown in Figure 9. 9
4.4.4 Enclosure
JB/T2740-1996
Simplified form of 5 conductors
Simplified form of 5 conductors
When it is necessary to show that a certain part in the figure represents a functional unit, structural unit or item group (such as an electrical group, relay device), it can be represented by a dotted line enclosure. In order to make the drawing clear, the shape of the enclosure can be irregular. The frame line should not intersect with the component symbols, except for plug, socket and terminal symbols. They can be on the frame line, inside the frame line, or can be omitted. The symbols inside or on the frame line belong to the components of the unit. When a unit is represented by a frame, if a mark for more detailed information is given in the frame, the circuit inside it can be represented in a simplified form.
If the figure inside the frame representing a unit contains component symbols that do not belong to the unit, these symbols must be surrounded by double dotted lines and marked with codes or annotations. See Figure 10. When the shield or ground surrounds the entire structural unit, the boundary line (dotted line) should be omitted. 0
Key points not covered in 06
4.4.5 Simplified method
4.4.5.1 Terminals
Multiple terminals in a component can be represented by one terminal symbol. In particular, in system diagrams, terminal codes can be separated by commas. If the terminals are numbered consecutively and there is no confusion, only the first and last codes can be indicated, separated by a dot. As shown in Figure 11. &
Same symbols in a group
Same symbols in a group can be indicated by one symbol, and a slash is added to indicate the number of the same symbols. Especially for the square 10
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