Electrical Panel Wiring Diagram

Electrical panel wiring diagrams are used to outline each device, as well as the connection between the devices found within an electrical panel. As electrical panels are what will contain control systems, panel wiring diagrams are commonly encountered by PLC technicians and engineers. Although electrical panels may not be overly complex from the first glance, a lot of engineering goes into selecting proper devices, sizing wiring and designing the layout of the panel that is documented by the electrical panel wiring diagrams.


This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/electrical-panel-wiring-diagram

Great article, that I enjoyed reading.
Being in Australia I have found that some purpose-built machines from Europe and Asia lack the clarity or detail you describe. This makes fault finding a very hard task and generally leads to the black box (PLC fault) syndrome when a fault is found. This is why professional documentation of both the panel and PLC program is essential for minimizing maintenance budget blowouts.

BTW: Found the diagrams on the link you provided.

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I completely agree with you. I am surprised that although the NEC regulates how these drawings should be presented, a lot of machine builders get away with sub-par panel drawings. From my experience, having been to multiple plants, I’m happy to see that there are drawings inside a panel at all. In most cases, they are missing, out-dated, one some-ones laptop who quit over a decade ago, etc.

Documentation is key, as you pointed out. I believe that managers are responsible for the state of their machinery and let it degrade quickly as it arrives to a plant. That being said, control systems aren’t always the most understood topic by management who doesn’t have that background.

On that note, one of the first questions I ask when I go to a new facility, during an audit or interview is to see their panel drawings. Based on their response, I can immediately tell how well or poorly the plant is ran by the management team. I find that the state of their documentation reflects on all areas of their work. In other words, if they don’t maintain solid documentation in their panels, they’re likely to cut corners in operations, engineering, etc.

Thank you for the feedback.

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