How to Follow an Electrical Panel Wiring Diagram

How to Follow an Electrical Panel Wiring Diagram

This video is unlike any of
the videos we’ve done before. We’re going to delve into
the world of panel drawings! This is an exceptionally useful
weapon to have in our armory, as it not only helps us to build panels
and understand the inner workings of them, but they help to troubleshoot
problems if they occur later. If you can follow a wiring diagram, you will be able to find the root
cause of any problem in a panel! But before all of that, please don’t forget to like this
video if you find it useful. And if you can think of anything
you think we may have missed, let us know in the comments, and we’ll see if we can put
together a video on your topic too! In this video, we’re going to go back
and have a look at the control panel, and try and figure out
some of the connections by following a wiring diagram. As we’ve said before, this is a
control panel that is used for a system that turns wastewater into clean water. It is a 2-door control
panel on the front of which we have some switches that are
connected to the PLC inputs and outputs. We are going to look at these switches and
try and figure out the wiring behind them, as you may be curious as to how
these switches are wired to the PLC! Let us first identify our push buttons; we have the “Mute Buzzer” push button, the “ESD Reset” push button, and the “Emergency Stop” push button. Try to remember these and see if we can find any of these
items in the electrical drawings. All the wiring that you see here is done based
on this wiring diagram that we have here. This is what we draw using AutoCAD. Each page of this wiring
diagram shows the exact wiring for different sections
of this control panel. For instance, for our Emergency
Stop pushbutton here on this page, it shows the wiring for this switch. You see that there are four wires
that are connected to this switch. These are the wires that we have here, on the back of the
Emergency Stop push button, on the rear of the door. Each of these wires has a tag number. The tags for these two wires are 1 and on the other end is 2. For this upper wire, it shows that there is a wire that
comes from page 200 section 1. So we have the page numbers here. For example,
here it shows that we are on page 311. Now this wire comes
from page 200 section 1. So I’ll go to page 200 and then section 1 and here is where this wire comes from. Here as you can see it says this
wire goes to page 311 section 1, which is the page and the
section that we were looking at. So if I go to page 311 and section 1 I can see this wire. Now if I go back to page 200, you see that this wire comes
from page 150 section 9. So if I go to page 150 and section 9, I can see where this wire comes from. Here you can see that it says the
wire goes to page 200 section 0 which is where we just came from. So this wire goes to page
200 section 0 which is here. Then it goes to page 311 section 1. wThis is page 311 section 1 and this is the wire that is connected
to the Emergency Stop push button. The same goes for the other wires as well. For example, this wire comes
from page 310 section 9. This one comes from page
200 section 1 again. And this one connects to here
which is our PLC digital input. This is the tag for the PLC input. It shows 300U2.1. Now, this is the back of the
Emergency Stop push button. You see that we have four wires here, just as what we have on the wiring diagram. These are the two wires
that are tagged as 1 and these are the two
wires that are tagged as 2. Based on the diagram,
one of these wires with the tag 2 goes to the PLC digital input. Let’s see if we can find this wire. Here it says the tag for the PLC input that the push button is
connected to is 300U2.1. These are the tags for the
PLC inputs and outputs. The one I am looking for is this one here. Now based on the diagram I need to look for a
wire that is tagged as 2. So I’ll look here and this is
the wire that I am looking for. So one end of this diagram is
connected to the push button nd the other end is
connected to the PLC input. So this is how easy it is to read the
wiring diagram for a control panel. It goes exactly the same for the other
switches that we have here as well. That’s it for this video! There was a
lot of back and forth in that video, hopefully, you didn’t get lost! If you didn’t, you’re well on your
way to becoming an AutoCAD designer, or panel wireman, or maybe you
want to work out in the field?! Well, you’re on track for that too. Again this video was
brought to you by RealPars in partnership with Pro-control
here in the Netherlands. They are experts at control system
design and industrial automation. They have a team of world-class automation
engineers and have been designing and implementing industrial control systems
in different industries for many years. If you want to get in contact with them, you can check out their
website at That’s We will put a link to their website in
the description below the video as well. Ok, that’s all for today’s video. If you have learned something
new from this video, it would mean the world to
us if you like this video. If you haven’t already subscribed
to the channel, please do so. When you subscribe don’t forget to hit the
little bell next to the subscribe button to be notified each time
that we post a new video. If you have got any thoughts or
questions, add them in the comments below. We read each and every comment and
reply back to it in less than a day. Thanks for watching and we’ll
see you in the next video! Want to learn PLC programming
in an easy to understand format and take your career to the next level? Head on over to

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46 Replies to “How to Follow an Electrical Panel Wiring Diagram”

  1. This channel is so Much useful…. please keep making these videos….I am so grateful to you guys…. thanks a lot

  2. This is great work #REALPARS. Just wish could give more on this coz control diagram interpretation and understanding is very important as far as industrial automation is concern. Best channel ever!!!

  3. Thank you for showing the basics of reading a wire diagram and its relationship to a panel. Having been out in the field and being exposed to time critical breakdowns I know that practice reading and following wire flow problems really pays off in a crisis. Could it be possible to create a loose lesson plan using your videos? There are more than a few field techs that might find a lesson plan helpful. Again thank you.

  4. Ok here comes the critique:

    1. You're only using a single channel for your safety relay which is almost never done. Why only one channel? Is it a low PL / category application?

    2. You show two sets of wires with the same wire number (1 and 2). Those are contact terminal numbers and are already shown on the blocks. They should be labeled the same number as the wire it's attached to (4F2). The number 2 in itself tells you nothing. Which 2 is connected to the PLC? That should not be a question. The wire connected to the PLC should show the address of the I/O point on the card. Having a bunch of cards with the number 2 wired into an input point isn't very helpful.
    3. You have tags on the wire way cover. If that cover disappears, so does all your referencing. Those should be attached to the subpanel. Changing the wire labels to reference the I/O point eliminates this issue as well.

  5. Make more videos on drawing ..It help me a lot and how to make drawing inAutocad… # you make best videos with good concept

  6. The question is: which wire having tag 2 is going to the PLC? There are 2 wires having the same tag, how should i know which is the correct wire?

  7. FYI symbols in Europe are diffrent from e.g USA. I Europe vi use symbols from the standard EN 60617. I found a HP that have som descriptions of the symbols. In the bottom is it also categories for easy search:

  8. Good Stuff

    My Favorite electric drawings our supplied with our Volpak packet machines from Barcelona as try and finish each section without the page jumping

    And if you go to a section of the panel the first numbers on wire tags reference a page number on the drawing which is a huge time saver

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