An introduction to electrical engineeering drawing.pptx

Introduction to Electrical Engineering Drawing
Electrical engineering drawing is a specialized branch of technical drawing that focuses on the graphical representation of electrical systems and components. These drawings are essential tools for engineers, technicians, electricians, and architects, as they provide a visual guide for the design, installation, maintenance, and troubleshooting of electrical systems. Electrical engineering drawings ensure that electrical systems are built according to precise specifications and adhere to safety standards and regulations.

Importance of Electrical Engineering Drawings
Electrical engineering drawings serve several critical functions:

Design and Planning:

These drawings are used during the design phase of electrical systems, enabling engineers to plan the layout of electrical circuits, components, and systems in buildings, machines, and other structures. They help ensure that the design is efficient, functional, and safe.
Installation and Construction:

Electricians and technicians rely on electrical engineering drawings to install electrical systems accurately. The drawings provide detailed instructions on the placement of wiring, conduits, outlets, switches, and other components, ensuring that the installation meets design specifications and complies with safety standards.
Maintenance and Troubleshooting:

Electrical drawings are indispensable during maintenance and troubleshooting. They allow technicians to trace circuits, identify components, and diagnose issues within the system. Accurate drawings reduce the time and effort required to locate and fix problems, minimizing downtime and maintenance costs.
Documentation and Compliance:

Electrical engineering drawings serve as official documentation of an electrical system's design and configuration. They are often required for regulatory approvals and inspections, ensuring that the system complies with local, national, and international codes and standards.
Communication:

These drawings facilitate clear communication among various stakeholders involved in a project, including engineers, contractors, electricians, and inspectors. By providing a common visual language, electrical drawings help prevent misunderstandings and errors during the design and installation process.
Types of Electrical Engineering Drawings
Electrical engineering drawings can be categorized into several types, each serving a specific purpose. Some of the most common types include:

Schematic Diagrams:

Schematic diagrams represent the logical flow and connections within an electrical circuit. They use standardized symbols to represent components such as resistors, capacitors, switches, and power sources. Schematic diagrams do not necessarily show the physical layout but focus on the functional relationships between components.
Wiring Diagrams:

Wiring diagrams, also known as connection diagrams, show the physical connections between components in an electrical system.

1. ELECTRICAL ENGINEERING DRAWING

2. Review of Engineering Drawing Is a graphical language used by Engineers and other personnel associated with the Engineering profession. The purpose of engineering drawing is to convey graphically the idea and information necessary for contraction or analysis of machines or systems. The drawing often includes such features as various types of lines, dimensions, lettered notes, section views and symbols. The drawing must be carefully planned and checked.

3. Methods 1. Drafting . The making of drawing of objects, structures or symbols that have been visualized by engineers or scientists or others. Such drawings may be executed in the following ways; a) Manually with drawing instrument. b) Free hand with a pencil on a paper. c) Other aids such as templates and oblique. d) Automated devices.

4. 2. Schematic Drawing A schematic , or schematic diagram , is a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures. 3. Dimensioning This is the assigning of dimensions on a mechanical or electrical drawing.

5. Drawing requirements Drawing paper, Cell tape, Flinch curves, Drawing board, Pencil(s) Adequate light. Sharpening tool, Circle templates Flexible curves, Compass, Razor, Table/ desk A computer

6. Drawing paper Drawing paper is described to fall under series called “A” series; A0: 1189mm x 841mm A1: 841mm x 594mm A2: 594mm x 420mm A3: 420mm x 297mm A4: 297mm x 210mm

7. Paper layout

8. Electrical Engineering Drawing Electrical Engineering Drawing is a type of technical drawing that shows information about power, lighting, and communication for an Engineering or Architectural project. Any electrical working drawing consists of "lines, symbols, dimensions, and notations to accurately convey engineering’s design to the workers, who install the electrical system on the job".

9. Electrical Engineering Drawing cont’d… A complete set of working drawings for the average electrical system in large projects usually consists of: A plot plan showing the building's location and outside electrical wiring Floor plans showing the location of electrical systems on every floor Power-riser diagrams showing panel boards Control wiring diagrams Schedules and other information in combination with construction drawings

10. How to Draw Electrical Diagrams Making wiring or electrical diagrams is easy with the proper templates and symbols: Start with a collection of electrical symbols appropriate for your diagram Drag and drop symbols to the circuits and connect them Draw circuits represented by lines Use line hops if any lines need to cross Add layers to show complexity

11. Types of Drawings Drawings commonly used by the electricians are as below; Schematic drawing Circuit drawing Block/line drawing Wiring drawing Layout drawing

12. Line diagram A one-line diagram or single-line diagram is a simplified notation for representing an electrical system.

13. Schematic A schematic , or schematic diagram , is a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures.

14. Wiring diagram Shows how the components will be wired, how and where the connections will be made. The components are often drawn to physically look like what they represent and are often placed on the drawing in the positions that they represent that they will actually take in the equipment. A wiring diagram usually gives information about the relative position and arrangement of devices and terminals on the devices, to help in building or servicing the device.

15. Wiring Diagram

16. Architectural / Layout Wiring Diagrams An architectural or Layout Wiring diagram show shows the layout of plant and equipment with details of approximate locations and interconnections of receptacles, lighting, and permanent electrical services in a building. Interconnecting wire routes may be shown approximately, where particular receptacles or fixtures must be on a common circuit.

17. Architectural / Layout Wiring Diagrams cont’d.. The electrical symbols not only show where something is to be installed, but also what type of device is being installed. For example, a surface ceiling light is shown by one symbol, a recessed ceiling light has a different symbol, and a surface fluorescent light has another symbol. Each type of switch has a different symbol and so do the various outlets. There are symbols that show the location of smoke detectors, the doorbell chime, and thermostat. On large projects symbols may be numbered to show, for example, the panel board and circuit to which the device connects, and also to identify which of several types of fixture are to be installed at that location. A set of wiring diagrams may be required by the electrical inspection authority to approve connection of the residence to the public electrical supply system.

18. Circuit Diagrams They show clearly the way that components are connected for a given equipment using BS 3939 symbols. The layout and interconnections bear no relation to the way that this will actually be on the equipment.

19. Block/ Line Diagrams Used square blocks to represent plant/ equipment. Lines are drawn showing interconnections not actual wiring. Details of what the blocks represent can be written at the side of each block. The specification of the cables of the interconnection lines should be written.

20. The Importance of Electrical Engineering Drawing to the Electro-Technical Industry Used in the design of Electrical and Electronic systems. Helps in the location of faults for repair and maintenance work. Helps in installation work to determine the exact locations of different components and accessories. Enables the Engineer to make modifications at a later time basing on the previous designs. Used to estimate the cost/make Bills of Quantities of a project.

21. Commonly Used Symbols and their Meaning for House Electrical Plans.