Technical Article

Motor Starter Wiring Infographic

February 06, 2024 by David Peterson

Complete wiring guide for 3-phase motor starters with and without overload (OL) relays.

Starting motors involves a tremendous current, and certain devices are in place to start and protect the motor control circuit.

Motor Starter wiring poster

Figure 1. Various methods of starting and driving 3-phase motors with direct online (DOL) starters. Click on the image to see a high-res (printable 11x17 size) version.

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2 Comments
  • T
    TeckyWalla February 16, 2024

    I much prefer the standard method of displaying via ladder style diagrams as shown in NFPA79 etc, rather than overly artistic versions used in the articles.

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    • D
      David Peterson February 16, 2024
      I prefer the ladder styles as well. However, this article is about the physical wiring, while ladder diagrams show the logical control structure. Both are necessary in order for the system to work. These diagrams for physical wiring do show the proper 3-phase wire colors with enough contrasting colors to make it more clear. I've worked with many wiring diagrams that are black and white, and many others that are illustrated in proper colors, and colorized diagrams are easier to follow 100% of the time. For the ladder-style control diagrams, this resource may be more helpful: https://control.com/technical-articles/introduction-to-basic-three-phase-motor-control-circuits/
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