Download INTRODUCTION TO PLC ELECTRICAL CONTROL PANEL and more Study notes Electrical and Electronics Engineering in PDF only on Docsity!
Electrical Symbols An electrical symbol is a graphical representation used to represent electrical components or devices in schematic diagrams or circuit diagrams. These symbols are standardized and universally recognized, making it easier for engineers, technicians, and electricians to understand and interpret electrical plans. Wires Symbols Symbol Name Description Electrical Wire It is the symbol that is used to represent a wire. Connected Wires This Symbol represents the wire connected crossing. Not Connect Wires This Symbol shows that wires are not connected on crossing. Switches Symbols Symbol Name Description SPST Toggle Switch It is the symbol of a switch that disconnects current when open. SPDT Toggle Switch This Symbol of switch selects between two connections.
Push Button (N.O) It is a symbol that denotes Momentary switch - normally open. Push Button Switch (N.C) This denotes the symbol of a Momentary switch - normally closed. DIP Switch It is the symbol of the DIP switch which is used for onboard configuration. Relays Symbol Name Description SPST Relay This shows the symbol of relay that close connection by an electromagnet.
Inductors Symbol Name Description Inductor Symbol of a Coil / solenoid that generates a magnetic field. Iron Core Inductor It is the symbol of the iron core Inductor Which Includes iron. Variable Inductor It is the coil or solenoid that has a Variable magnetic field. Motor and Transformer Symbol Name Description Motor Symbol of motor, which changes electric energy to kinetic energy.
AC Transformer Transformer changes AC voltage from high to low or low to high. 2.2 Electronics Symbols An electronic symbol is a graphical representation used to represent electronic components or devices specifically in electronic circuits. Electronic symbols are similar to electrical symbols but are more specific to electronic components such as transistors, diodes, integrated circuits, and other electronic devices. Resistance Symbol Name Description Variable Resistance It is the symbol of an adjustable resistor which has 2 terminals. Potentiometer It is the symbol of an adjustable resistor that has 3 terminals. Trimmer Resistor It is the symbol of a trimmer which is also known as a Preset
LED emits light when current flows through it. This is the symbol of Photodiode that allows current flow when exposed to light. Capacitor Symbol Name Description Capacitor Capacitor is used to store electric charge. It acts as a short circuit with AC and an open circuit with DC. Variable Capacitor The Symbol represent the adjustable capacitance. Sources Symbol Name Description Voltage Source It is the symbol of a voltage Source which generates constant voltage.
Current Source It is the symbol of a current Source which generates constant current. AC Voltage Source This symbol shows the AC Voltage Source. Battery Cell It is the symbol of single cell use to generate constant volt. Battery It is the symbol of a battery which is the combination of two or more cells.
Wattmeter This represents the power meter which shows the power consumption. Converter and Amplifier Symbols Symbol Name Description Operational Amplifier This operational gives Amplify input signal. Analog to Digital Converter This is the symbol of ATD converts analog signal to digital numbers. Digital to Analog Converter This is the symbol of DTA converts digital numbers to analog signals.
Transistors Symbols Utility Symbols Symbol Name Description BUZZER Produce a buzzing sound when current flows through it. Electric Bell This is the symbol of Bell which Rings when activated. Fuse The fuse disconnects when the current is above the threshold--- used to protect a circuit from high currents. Bus The bus symbol contains several wires. Usually for data/address. Loudspeaker Convert electrical signals to sound waves.
The same current flows through all components Resistance increases as more components are added Potential difference is shared between components An example is a string of decorative lights, where all the bulbs are connected in series
A parallel connection is when components are connected across each other's leads, allowing current to flow through multiple paths. How it works Each component has the same voltage across it. The total current is the sum of the currents through each component. If one component breaks, the others can still operate. Types of Electrical Drawing and Diagrams In Electrical and Electronics Engineering, we use different types of drawings or diagrams to represent a certain electrical system or circuit. These electrical circuits are represented by lines to represent wires and symbols or icons to represent electrical and electronic components. It helps in better understanding the connection between different components. Electricians rely on electrical floor plan (which is also an electrical diagram) for carrying out any building wiring. Engineers use various types of electrical drawings to highlight certain aspects of the system but the physical circuit and its function still remains the same. Some of these electrical drawings or diagrams have been described below: simplest form of electrical drawing as it only highlights the function of each component and provides the flow of process in the system. Schematics Circuit Diagram
Pictorial Diagram The pictorial diagram does not necessarily represent the actual circuit. In fact it shows the visual appearance of the circuit in real time. it cannot be used to understand or troubleshoot the actual circuit and for this reason alone, it is not commonly used. For someone with less knowledge of electrical, it is impossible to understand how the circuit works and diagnose it.
Ladder Diagram or Line Diagram: Ladder diagram are electrical diagrams that represents an electrical circuit in industries to document control logic systems. It resembles a ladder which is why it is named ladder diagram. There are two vertical lines; the left vertical line represents power rail (voltage source) while the right vertical line represents the ground or neutral. Each horizontal row represents a parallel circuit called rung. A ladder diagram is simple, easier to understand and helps in troubleshooting the circuit quickly.
