What is the difference between wiring diagram and schematic diagram? Detailed explanation of difference between electrical schematic diagram and wiring diagram

This article mainly introduces the difference between the wiring diagram and the schematic diagram. We use electrical schematics and wiring diagrams to do a detailed analysis. First introduced the type of electrical schematic diagram and the method of the humidity electrical diagram, followed by the description of the electrical wiring diagram drawing requirements, etc. Finally, the difference between the electrical schematic diagram and the wiring diagram is introduced, and the specific following Xiaobian together to find out.

The electrical schematic diagram is used to indicate the working principle of the electrical equipment and the role of the various electrical components, and a representation of the relationship between each other. The use of electrical schematics methods and techniques is very useful for analyzing electrical circuits and eliminating machine circuit failures. Electrical schematics are generally composed of main circuits, control circuits, protection, and distribution circuits.

Electrical drawings can generally be divided into two major categories. One is the electrical power diagram. It is mainly used to describe the transmission, distribution, and conversion of electrical energy, such as electrical diagrams of electrical networks, electrical control diagrams of power plants, and so on. The other type is an electrical and electronic diagram, which mainly represents the transmission and processing of electronic information; such as the TV electrical schematic diagram.

The electric power diagram is divided into a primary circuit diagram and a secondary circuit diagram. The primary circuit diagram shows the primary electrical equipment (main equipment) connection sequence. Primary electrical equipment includes generators, transformers, circuit breakers, motors, reactors, power cables, power buses, transmission lines, etc.

For the primary equipment and its circuit control, measurement, protection and design and installation of various types of electrical equipment, such as measuring instruments, control switches, relays, signal devices, automatic devices, such as secondary equipment. The electrical diagram indicating the connection sequence between the secondary devices is called the secondary loop diagram.

Electrical diagrams mainly include system schematics, schematics, and wiring diagrams.

1. The system schematic (block diagram)

With simpler symbols or boxes with words, the most basic structure and composition of the circuit system are represented simply and clearly, and the most basic structural elements and the main features and relationships between the circuits are visually expressed.

2. Circuit schematic

The circuit schematic is divided into two types: centralized and expanded. All components and parts in the centralized circuit diagram are drawn together in an integrated manner to explain the structural principles and working principles of the components. When reading, it is necessary to clearly understand what loops the relay related coils and contacts in the diagram belong to, and under what conditions, what kind of changes occur in the contacts of relevant parts after the action.

The expanded circuit diagram has its unique advantages over the centralized circuit diagram in demonstrating the principle of the operation of each element, relay, and operation sequence. Expanded circuit diagram according to the coil components, contacts are divided into their own independent AC current, AC voltage, DC signal and other circuits. All currents, voltage coils, and contacts that belong to the same component or relay use the same text. In the unfolded circuit diagram, for each independent circuit, the AC is in U, V, W phase sequence; the DCs are arranged in sequence according to the relay action sequence. When reading the expanded circuit diagram, compare the text description on the right side of each loop, first exchange the DC and then read it from top to bottom and from left to right. Centralized and expanded circuit diagrams complement each other and contrast each other to make reading easier to understand.

3. Installation wiring diagram

The installation wiring diagram is drawn based on the circuit principle and is an indispensable and important material for on-site maintenance. The figure, position and connection relationship between each component in the installation drawing are consistent with the actual shape of the components, the actual installation position and the actual connection relationship. The connection relationship in the figure is represented by a relative labeling method.

1. Read the equipment manual and operation manual carefully to understand the operation mode and sequence of the equipment and the function of the equipment components in the circuit.

2. Compare drawings and drawings with a general understanding of the structure of the electrical system, and combine the contents of the main headings with a clearer understanding of the type, nature, and role of the circuit represented by the entire drawing.

3. Read the system schematic to see the drawings. Combine the contents of the instructions with the drawings to understand the approximate status of the entire circuit system, the sequence of component operations, and the control methods. Make necessary preparations for reading detailed circuit schematics.

4. To read the centralized and unfolded circuit diagrams, first look at the primary circuit, then the secondary circuit, first exchange the sequence of the post-dc flow, and from the top to the bottom, from left to right, gradually progressively, look at the various loops, and The status of each circuit device element and the control of the main circuit are analyzed comprehensively to understand the working principle of the entire electrical system.

5. Read the installation wiring diagram to compare the electrical schematics, the first loop, then the secondary loop sequence reading. Read the installation wiring diagram in combination with the circuit diagram to learn more about the meaning of the terminal symbol and the circuit symbol. For a circuit to read from the power supply side by side to understand the circuit connection and direction. Until the end of the power equipment. The secondary circuit must be read from one end of the power supply until the other end of the power supply. All wires with the same wire number in the wiring diagram. In principle, all can be connected together.

The electrical wiring diagram is drawn based on the actual position and installation of electrical equipment and electrical components. It is used only to indicate the location, wiring, and wiring of electrical equipment and electrical components. It does not clearly show the principle of electrical operation. Mainly used to install wiring, line inspection and maintenance and troubleshooting.

1, the wiring diagram generally shows the following: the relative position of electrical equipment and electrical components, text symbols, terminal number, wire number, wire type, wire cross section, shielding and wire stranding.

2. All the electrical equipment and electrical components are drawn on the drawing according to their actual location. The components of the same electrical appliance are drawn together with the same graphical symbols as the circuit diagram according to their actual structure, and are drawn on the wireframe. The number of text symbols and terminal blocks should be the same as those in the circuit diagram in order to check the wiring.

3, the wire in the wiring diagram has a single wire, wire group (or cable), cable, etc., can be used to represent the continuous line and interrupt line. Where the conductors are the same, they can be combined and represented by wire harnesses. When reaching the connection points of the terminal board or electrical components, they are drawn separately. When a wire harness is used to represent a wire group, a cable, or the like, it may be indicated by a bold line, and a partial thickening may be used without causing misunderstanding. In addition, the type, number, and specifications of wires, bushings, and conduits should be clearly marked.

The electrical wiring diagram used for electrical equipment is used to organize the port number of each component in the electrical equipment and the number of the wire cable for the port. It also organizes and compiles the number of the terminal block to guide the reasonable wiring installation and facilitate the future. Maintenance electrician to find fault as soon as possible

The electrical wiring diagram of the power system mainly shows the electrical connections between the main motors, electrical appliances and lines of generators, transformers, busbars, circuit breakers, and power lines in the system; a more detailed understanding of the system can be obtained from the electrical wiring diagrams. .

1) The electrical components in the electrical wiring diagram are drawn according to the shape (such as square, rectangle, circle or their combination) and are consistent with the layout diagram, and the deviation should not be too large. The internal conductive parts of the device (such as contacts, coils, etc.) are drawn according to their graphic symbols.

2) In the wiring diagram, the text symbols, component connection order, and connection number of each electrical component must be the same as the schematic diagram. The wiring number should comply with GB4026-83 "General requirements for identification of electrical terminals and marking terminals with alphanumeric symbols"

3) Different from the electrical schematic diagram, all parts (contacts, coils, etc.) of the same electrical component must be drawn together in the wiring diagram.

4) In addition to large cross-section conductors, the inlet and outlet lines of each unit shall pass through the terminal board and shall not be directly accessed. Terminals on the terminal board are arranged in the order of wiring numbers, and power lines, AC control lines, and DC control lines are arranged in a sorted manner.

5) The connection wires and cables in the wiring diagram should generally indicate the types, specifications, cross-sectional areas and color requirements of the various wires for wiring.

1, unit wiring diagram

The unit wiring diagram is a diagram showing the connection of each item inside the electric unit, usually does not include the external connection between the units, but can give the drawing number of the interconnection wiring diagram related to it.

The wiring diagram of the unit wiring pattern includes two kinds: the front board trace and the rear board trace. Generally, the front board trace is used. For the complex unit, the wire trunking is generally adopted.

The wiring relationships between the electrical components in the unit wiring diagram are direct and indirect. For a simple electrical control unit, the number of electrical components is small, the wiring relationship is not complicated, and the connection between electrical components can be drawn directly; for a complex unit, the number of electrical components is large, and the wiring is complicated, as long as it is on each electrical component. Mark the wiring number, do not have to draw the connection between the components.

The wiring diagram of the unit wiring is as follows:

1) In the unit wiring diagram, the simplified shape and graphical symbols representing the items are arranged according to certain rules. This rule is generally arranged according to the relative position of each item. The distance between items is not based on the actual distance, but It depends on the complexity of the connecting line.

2) The view selection of the unit wiring diagram should clearly show the terminals and wiring of each item. Multiple views can be used when one view does not clearly represent multiple facets.

3) When items are stacked on top of each other in several layers, these items can be flipped or moved to draw a view, and instructions can be added.

4) For items such as PLCs, transfer switches, and combination switches, they have multiple layers of terminals and the upper terminals cover the lower terminals. In this case, the covered terminals can be extended to indicate the wiring relationship of each layer.

2, interconnection wiring diagram

The interconnection wiring diagram is used to indicate the connection between different units in a complete set or device, and usually does not include the internal connection of the involved unit, but the drawing number of the related circuit diagram or unit connection diagram can be given. The views of the units in the interconnecting wiring diagram should be drawn on the same plane to indicate the connection relationship between the units.

The schematic diagram is the working schematic diagram of the circuit. The expression means how the various components work. The wiring diagram is how the various components and components are connected to each other.

The installation diagram is the representation of the dimensions of each component in the control cabinet. In the electrical system diagram, most of the electrical schematic diagrams are used. To facilitate the reading and analysis of the control circuit, the electrical components are drawn in the form of simple and clear principles. It includes the conductive parts and terminal points of all electrical components, but it is not drawn in accordance with the actual position of the electrical components, nor does it reflect the shape, size, and mounting of electrical components.

The wiring diagram is based on the layout of the electrical appliances, main contacts, auxiliary contacts, coil terminals, and control terminal terminals are clearly shown on the diagram. Only the electrical symbols of the electrical appliances are displayed on the diagram. Now we see The drawings are based only on schematics and are relatively simple and easy to read. The wiring diagrams are too cumbersome and dazzling.

The schematic diagram refers to a detailed circuit diagram, focusing on the electrical principle and knowing why it is wired.

The wiring diagram is used to connect the operator, and the focus is to make the complicated line type clear and easy to connect. According to the schematic diagram, it can be wired, but it is easy to make mistakes in the case of a lot of lines, and the requirements of the workers are very high. The line number and model of the line are marked in detail, the wiring principle is not displayed, the construction is convenient, and the requirements for workers are low.

Because the electrical schematic has the advantages of simple structure, distinct layers, suitable for research, and analysis of the working principle of the circuit, it has been widely used in both the design department and the production site.