Wiring diagram example

What is a Wiring Diagram?

A wiring diagram is a simple visual representation of the physical connections and physical layout of an electrical system or circuit. It shows how the electrical wires are interconnected and can also show where fixtures and components may be connected to the system.

When and How to Use a Wiring Diagram

Use wiring diagrams to assist in building or manufacturing the circuit or electronic device. They are also useful for making repairs.

DIY enthusiasts use wiring diagrams but they are also common in home building and auto repair.

For example, a home builder will want to confirm the physical location of electrical outlets and light fixtures using a wiring diagram to avoid costly mistakes and building code violations.

How to Draw a Circuit Diagram

SmartDraw comes with pre-made wiring diagram templates. Customize hundreds of electrical symbols and quickly drop them into your wiring diagram. Special control handles around each symbol allow you to quickly resize or rotate them as necessary.

To draw a wire, simply click on the Draw Lines option on the left hand side of the drawing area. If you right click on a line, you can change the line’s color or thickness and add or remove arrowheads as necessary. Drag a symbol onto the line and it will insert itself and snap into place. Once connected, it will remain connected even if you move the wire.

If you need additional symbols, click the arrow next to the visible library to bring up a drop down menu and select More. You’ll be able to search for additional symbols and open any relevant libraries.

Click on Set Line Hops in the SmartPanel to show or hide line hops at crossover points. You can also change the size and shape of your line hops. Select Show Dimensions to show the length of your wires or size of your component.

Click here to read SmartDraw’s complete tutorial on how to draw circuit diagrams and other electrical diagrams.

How is a Wiring Diagram Different from a Schematic?

A schematic shows the plan and function for an electrical circuit, but is not concerned with the physical layout of the wires. Wiring diagrams show how the wires are connected and where they should located in the actual device, as well as the physical connections between all the components.

How is a Wiring Diagram Different from a Pictorial Diagram?

Unlike a pictorial diagram, a wiring diagram uses abstract or simplified shapes and lines to show components. Pictorial diagrams are often photos with labels or highly-detailed drawings of the physical components.

Standard Wiring Diagram Symbols

If a line touching another line has a black dot, it means the lines are connected. When unconnected lines are shown crossing, you’ll see a line hop.

Line hops

Most symbols used on a wiring diagram look like abstract versions of the real objects they represent. For example, a switch will be a break in the line with a line at an angle to the wire, much like a light switch you can flip on and off. A resistor will be represented with a series of squiggles symbolizing the restriction of current flow. An antenna is a straight line with three small lines branching off at its end, much like a real antenna.

Wiring diagram symbols

  • Wire, conducts current
  • Fuse, disconnect when current exceeds a certain amount
  • Capacitor, used to store electric charge
  • Toggle Switch, stops the flow of current when open
  • Push Button Switch, momentarily allows current flow when button is pushed in, breaks current when released
  • Battery, stores electric charge and generates a constant voltage
  • Resistor, restricts current flow
  • Ground wire, used for protection
  • Circuit breaker, used to protect a circuit from an overload of current
  • Inductor, a coil that generates a magnetic field
  • Antenna, transmits and receives radio waves
  • Surge protector, used to protect a circuit from a spike in voltage
  • Lamp, generates light when current flows through
  • Diode, allows current to flow in one direction indicated by an arrowhead or triangle on the wire
  • Microphone, converts sound into electrical signal
  • Electrical motor
  • Transformer, changes AC voltage from high to low or vice versa
  • Headphone
  • Thermostat
  • Electrical outlet
  • Junction box

Wiring Diagram Examples

The best way to understand wiring diagrams is to look at some examples of wiring diagrams.

Click on any of these wiring diagrams included in SmartDraw and edit them:

Browse SmartDraw’s entire collection of wiring diagram examples and templates

Helps you learn about the basics of wiring diagram – what symbols to use, how to read, and how to make wiring diagrams.

What’s Wiring Diagram

A wiring diagram is a type of schematic which uses abstract pictorial symbols to show all the interconnections of components in a system. Wiring diagrams are made up of two things: symbols that represent the components in the circuit, and lines that represent the connections between them. Therefore, from wiring diagrams, you know the relative location of the components and how they are connected. It’s a language engineers need to learn when they work on electronics projects.

Simplest Wiring Diagram

Wiring Diagram VS. Schematics

It’s easy to get confused about wiring diagrams and schematics. Wiring diagrams mainly shows the physical position of components and connections in the built circuit, but not necessarily in logic order. It emphasizes on the layout of the wires. Schematics emphasize on how circuits work logically. It reduces integrated circuits into sub-components to make the system’s functional logics easier to understand . It’s most useful for learning the overall operation of a system.

How to Read Wiring Diagram

Recognize Wiring Diagram Symbols

To read a wiring diagram, first you have to know what fundamental elements are included in a wiring diagram, and which pictorial symbols are used to represent them. The common elements in a wiring diagram are ground, power supply, wire and connection, output devices, switches, resistors, logic gate, lights, etc. A list of electrical symbols and descriptions can be found on the “electrical symbol” page.

Simple wiring symbols

Line Junction

A line represents a wire. Wires are used to connect the components together. All points along the wire are identical and connected. Wires on some places need to cross each other, but that does not necessarily mean that they connect. A black dot is used to indicate the injunction of two lines. Main lines are represented by L1, L2, and so on. Usually different colors are used to distinguish the wires. There should be a legend on the wiring diagram to tell you what each color means.

Contact and No Contact

Types of Connection

Usually circuits with more than two components have two basic types of connections: series and parallel. A series circuit is a circuit in which components are connected along a single path, so the current flows through one component to get to the next one. In a series circuit, voltages add up for all components connected in the circuit, and currents are the same through all components. In a parallel circuit, each device is directly connected to the power source, so each device receives the same voltage. The current in a parallel circuit flows along each parallel branch and re-combines when the branches meet again.

Series and Parallel Circuit

Tips to Draw Good-looking Wiring Diagrams

  1. A good wiring diagram needs to be technically correct and clear to read. Take care of every detail. For example, the diagram should show the correct direction of the positive and negative terminals of each component.
  2. Use the right symbols. Learn the meanings of the basic circuit symbols and choose the correct ones to use. Some of the symbols have really close look. You need to be able to tell the differences before applying them.
  3. Draw connecting wires as straight lines. Use a dot to indicate line junction, or use line jumps to indicate cross lines that are not connected.
  4. Label components such as resistors and capacitors with their values. Make sure the text placement looks clean.
  5. In general it is good to put the positive (+) supply at the top, and the negative (-) supply at the bottom, and the logical flow from left to right.
  6. Try to arrange the placement reducing wire crossings.

Start with a Wiring Diagram Software

Professional wiring diagram software can produce high quality wiring diagrams with less time. Edraw wiring diagram software is a particularly designed application automating the creation of wiring diagrams with built-in symbols. It’s easy to use and compatible with Windows, Mac, and Linux platforms. With a comprehensive list of electronic symbols and components, it has been used as one of the most completed, simple and useful wiring diagram drawing program. You can get accustomed with it soon because the interface is quite familiar to MS programs. Easy to label the components, customize the colors of lines and symbols, and export the whole drawing into another format such as PDF, PNG, SVG, Visio, etc.

Wiring Diagram Software

Download Edraw Wiring Diagram Maker for Free:

Wiring Diagram Symbols

Start a wiring diagram design using industry-standard symbols that everybody understand. Here are the symbols that are often used when creating wiring diagrams. The symbols below all come from Edraw. It shows partially from the built-in electrical symbol library.

Switches and Relays
Switch 1PSPSTSPDTDPSTTwo way contactSwitch 3P
Resistors and Capacitors
ResistorAlternate resistorVariable resistorPre-set resistorPotentiometer resistorPotentiometer (Trimmer) 2
Electrical Instruments
Integrated Circuit Components
IC4X Building block-top4X Building block-base1X Building blockDriverMUX 8
Transformers and Windings
Magnetic coreInductorVariable inductorMagnetic core inductorTransformerPolyphase transformer
Transmission Path
Wiremulti line bus elbowJunctionJunction crossingLeft direction flowCable group

How to Draw Wiring Diagrams

First, make sure you have a tool that you know how to use. Take Edraw for example, you need to know where to find the electrical symbols and the right way to use the symbols. Although it seems all about dragging and dropping, it’s still better to learn some practical techniques to get things done quickly and smoothly. Read these useful points before starting a new design:

  1. Take a look at the Video Demo – How to Draw Circuit Diagram. It provides a step by step guide on how to use the program to draw wiring diagram.
  2. create wiring diagram

  3. Draw your wiring diagram under Engineer theme.
  4. engineer theme

  5. Find all the electrical wiring symbols in “Electrical Engineering” library.
  6. Some symbols can change more styles by clicking on the floating button on their top right side.
  7. change symbol style

  8. Connect the components with a Connector, not a Line.
  9. change symbol style

  10. Use Text button to draw new text boxes. (Note: Click the upper part of the button to draw text boxes. Use the Text Block Tool to edit existing text blocks on shapes.)
  11. Text Tool

  12. Set line jump style on “Page Layout” menu.
  13. Line Jumps

  14. To save the file as other format, click the “Export and Send” button on File menu.
  15. Export Wiring Diagram

Wiring Diagram Examples

1. Harness Wiring Diagram

This harness wiring diagram shows how to match up the wires for each connection to the wiring harnesses.

Harness Wiring Digram

2. Electrical Wiring Diagram

Create an electrical wiring diagram to display wire connections and physical layout of an electrical system or circuit.

Electrical Wiring Diagram

Read More:

Create Home Rewiring Plan

Home Wiring Plan

How to Read Electrical Circuits

Basic Home Wiring Diagrams

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Summary: Fully Explained Home Electrical Wiring Diagrams with Pictures including an actual set of house plans that I used to wire a new home. Choose from the list below to navigate to various rooms of this home*.

The Basics of Home Electrical Wiring Diagrams

The important components of typical home electrical wiring including code information and optional circuit considerations are explained as we look at each area of the home as it is being wired.

The home electrical wiring diagrams start from this main plan of an actual home which was recently wired and is in the final stages.

These links will take you to the typical areas of a home where you will find the electrical codes and considerations needed when taking on a home wiring project.

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Your home electrical wiring diagrams should reflect code requirements which help you enjoy lower energy bills when you implement energy efficiency into your the electrical project design.

Wiring Diagrams, Device Locations and Circuit Planning

A typical set of house plans shows the electrical symbols that have been located on the floor plan but do not provide any wiring details. It is up to the electrician to examine the total electrical requirements of the home especially where specific devices are to be located in each area and then decide how to plan the circuits.

The installation of the electrical wiring will depend on the type of structure and construction methods being used. For example, a stick frame home consisting of standard wood framing will be wired differently than a SIP or Structured Insulated Panel home because of access restrictions.
This electrical wiring project is a two story home with a split electrical service which gives the owner the ability to install a private electrical utility meter and charge a renter for their electrical usage.

Due to the separation between floor and the rental possibility this project was just like wiring two homes because there were separate services for furnaces, air conditioners etc.


Home Wiring from an Actual Set of Plans

Beautiful additions and upgrades to your home may increase the value, while providing tax incentives for you as you carefully plan your home electrical wiring diagrams. Code requirements along with energy efficient specifications can enhance your energy saving design and provide safety features to protect you and your family while enjoying your home project.

Home Electrical Wiring Blueprint and Layout


Home Electrical Wiring

Basic Home Wiring Diagrams

Fully explained home electrical wiring diagrams with pictures including an actual set of house plans that I used to wire a new home. Choose from the list below to navigate to various rooms of this home*.

Kitchen Electrical Wiring

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Kitchen Remodels – Part 1

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Kitchen Remodels – Part 2

Kitchen Remodels Part 2 covers Contractors, Permits, Codes and Inspections with Fully Explained Photos and Helpful Ideas.

Kitchen Remodels – Part 3

Kitchen Remodels Part 3 covers the Construction Phase with Circuits, Outlets and Lighting with Fully Explained Photos and Helpful Ideas.

Wiring a Range Power Cord

Electric Range Installation with a typical 240 Volt electric power cord wiring system for 3-wire and 4-wire configurations.

Wiring A Kitchen Oven

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Fully Explained Photos and Wiring Diagrams for Bathroom Electrical Wiring with Code Requirements for most new or remodel projects*.

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Home Improvement Electrical Considerations

When planning a home improvement project of any size special attention should be given to the electrical systems. Replacing worn out outlets and switches will help, but look at your options for higher efficiency lighting and code upgrades too.

Bedroom Electrical Wiring

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Garage Wiring

Fully Explained Photos and Wiring Diagrams for Garage Electrical Wiring with Code Requirements for most new or remodel projects*.

Workshop Electrical Wiring

Fully Explained Photos and Wiring Diagrams for Workshop Electrical Wiring with Code Requirements for most new or remodel projects*.

Basement Electrical Wiring

Fully Explained Photos and Wiring Diagrams for Basement Electrical Wiring with Basic Code Requirements for most new or remodel projects*.