How to Understand Wiring Schematics

Wiring schematics can be baffling if you aren't familiar with the basics of electronics, and using them without a full understanding can lead to defective circuits. Schematics are basically diagrams that represent an electrical circuit, complete with symbols that represent different components used within the circuit. Learning the basic principles behind wiring schematics is vital if you intend to use some to create or repair an electrical circuit. After you've gained an understanding of the symbols used in wiring schematics and what they represent, making sense of circuits as a whole is a much simpler process.

Understanding electrical schematics is essential if you intend on attempting a DIY repair.
  1. Learn about the representation of conductors. Conductors, simply put, are wires. They are a means of transporting the current between components, and they are represented by solid lines. If two wires connect, the connection is shown with a dot placed at the point of the intersection. Unconnected conductors may be shown to cross, but without a dot. Alternatively, one wire could "bridge" over the other.

  2. Search the diagram for any switches. Switches are points in the circuit where it can be disconnected. A common switch is a light switch, which literally is used to break and reform the circuit that powers the lights in your home. A circuit is shown by a break in the conductor line, surrounded by two dots. Inside the dots, a small portion of the line will be flayed off to the top, at a 45-degree angle.

  3. Learn how batteries are shown in diagrams. A battery is the power source in a circuit. These are shown by a series of parallel lines, one short, one long, another short and then the final one long. The short outer line represents the negative end of the battery, and for clarity, a "+" sign is generally included on the opposite side. The voltage is the amount of electrical power generated by the battery.

  4. Find examples of resistors on wiring schematics. Resistors literally resist the flow of electrical charge. This is useful for regulating the current that passes through circuits, and resistors are shown by a jagged line. Electrical resistance is measured in "ohms," and the resistor will normally be labeled accordingly. If a "K" is used when referring to a resistor, it stands for "kilo-ohms" or 1,000 ohms.

  5. Learn about the representation of ground points in the circuit. Grounding is used to protect circuits from over-voltage, and is included on many electrical schematics diagrams. It is shown on schematics by three parallel lines, which gradually decrease in size, as if someone has drawn three horizontal lines inside a triangle.

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