Diagrams

22 Transferring From Schematic to Wiring Diagram for Connection Purposes

A completed can help with the physical installation of wires. To aid in the development of a wiring diagram, it is useful to start with the circuit’s and the .

A wiring and schematic drawing

Consider the figure above. It includes a three-wire schematic diagram as well as the equivalent control components and the . In this example, there is no control transformer, so we will be taking control power directly from the line. The power is taken from the load side of the devices and the line side of the power contacts.

Once the schematic diagram has been properly numbered, each device will have two numbers identifying it, one wire on the line side, and one on the load side. For example, in a three-wire circuit, the stop button gets wires 1 and 2, while the start button and the holding contact each get wire numbers 2 and 3 (hence the term ““).

Schematic and wiring diagrams with numbers

Once all the devices have been properly numbered, we simply play connect the dots. Each point that shares the same number is and needs to be connected together. Use straight lines and only connect wires at terminal points on equipment.

Schematic and wiring diagrams – complete.

Make sure that all connections happen at termination points or “terminal to terminal.” In practice, we usually only connect a maximum of two wires to any one point and never make a “free-air splice.”

The figure above illustrates each of the strengths that wiring and schematic diagrams have: Schematic diagrams are easy to read and used to logically troubleshoot a circuit, while wiring diagrams show how equipment is physically connected together.

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Basic Motor Control by Aaron Lee and Chad Flinn is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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