Why do we need electrical and electronic symbols and why are electrical symbols important

What is the importance of electrical symbols and why circuit symbols are used

Electrical symbols are used to simplify the drafting and to understand the drawing. Electrical symbols are standardized throughout the industry. The addition of a line, dot, shading, letters, and numbers gives a specific meaning to a symbol. In order to achieve the ability to interpret the drawings and their related symbol meanings, we must learn the basic form of various symbols. Electrical symbols are required to do the electrical drawing and without the help of electrical symbols, we won’t be able to do the electrical drawing. Electrical circuits are represented by electrical drawings. Symbols and number combinations are used to represent electrical circuits. Electrical drawings can be used to convey information about a wide range of details such as Electrical wiring, pneumatic or hydraulic layouts, location of the equipment, and details of the equipment. By using electrical drawings we would be able to locate the equipment.

Why do we need electrical symbols and how to draw electrical diagrams

Electrical symbols can be used to represent various electrical equipment. In an electrical diagram, electrical equipment is represented with the help of electric symbols. Electrical drawings are usually drawn in a style called ladder diagram and another form of drawing is a wiring diagram. Electrical wiring diagrams use single lines from each device exactly as it would be wired. Electronic schematic uses symbols for each component found in an electrical circuit. Mostly electrical diagrams are multi-sheet drawings that show the wiring of the electrical devices related to the main control panel. Mostly electrical diagrams are drawn as a ladder diagram. Electrical diagrams are drawn between vertical lines or ladder all devices are shown between the lines and they are referred to as single-line diagrams. Controlled such as relays and devices are drawn on the right side. Control devices and switches are placed between controlled devices and the left vertical line. Overloads and other circuit breaking devices are connected to the right of the controlled device.

What are the most common circuit symbols and symbols in an electronic circuit

Power sources






Mutual inductors



Integrated circuits



By understanding a circuit symbol we could know how a circuit is connected together. The actual layout of the components is mostly different from the circuit diagram. In order to create a circuit, we need a different diagram showing the layout of parts on a stripboard or printed circuit board.

Electrical wire symbols


Contacts and switches

Meter symbols


Transistor symbol


Transformers and reactors


Earthing or grounding symbols

Coils and relay

How graphical symbols are used in electrical diagrams

Graphical symbols are used in electrical diagrams to show the wiring between electrical devices and terminals. Mostly the electrical devices are either shown in block diagram form or by using commonly defined symbols. A one-line diagram uses single lines and graphical symbols to indicate the path and components of an electrical circuit.

What is the importance of schematic diagram

The schematic wiring diagram is a drawing that uses symbols and lines to show how the parts of an electrical assembly or unit are connected. The schematic diagram won’t show where the parts are exactly located. But it explains how to make an electrical connection.

How circuiting symbols can be useful

An arrow indicates a branch circuit home run to the panel. The number of arrows shows the number of circuits. If there are no crosshatches then the raceway has two wires. Slash marks through the circuit lines indicate the number of conductors. Circuit conductors are represented by full slash marks, neutral is represented by longer full slash and the ground wires are represented by half slash marks.

How to do the control device labeling and wire identification

Limit switches, photocells, solenoids, etc are the control device that is shown in the wiring diagram. These devices are identified by the wiring diagram line number. Wire identification, the conductors are identified at each termination by marking with a number to corresponding with the diagram on the wire. The wiring color codes are

Black - line, and load

Red – AC control circuits

Blue – DC control circuits

Green - Equipment grounding

Yellow – interlock control circuits

White – grounded circuit conductor

How device abbreviations are used in electrical diagram

Electrical abbreviations are used adjacent to an electrical symbol. Abbreviations are used in an electrical diagram, in the combination of the corresponding graphical symbol in order to indicate the function of the device.