Wiring Diagram

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 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.

Standard Wiring Diagram Symbols

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.

• 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