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Motor Starters and Controls


Controls are widely looked at and misunderstood. They are nothing but switches turning devices on and off. Nothing complicated about that. Here are a few common views of symbols that you'll see on diagrams in the future. This will help you get your feet wet before we get into the line diagrams for functionality.
NO - means normally open, NC - means normally closed-- if you have any questions there is a portion at the bottom that reviews the abbreviations.

Line Diagrams

Now that you have the above symbols, looking at where to put them is next. We use line diagrams to tell us the circuit design. This is important after the circuit is built because of troubleshooting purposes, and possible expansion routes.
We`ll start with a graphical view of the circuit, and then what the same line diagram should look like for the example shown.

...and now the line diagram`s that simple. It`s even wired the same way you see it. You see the two switches above (which are pushbuttons) one is normally open, and one is normally closed. Using a car battery was extreme, but we thought you`d relate to the circuit better.
Now we can start adding phases and devices to make it look more like a circuit that you`re used to. Keep in mind we are showing you the `control circuit` so when you see the example below it, it is the 120V example.

As the circuit gets more complicated then you can add lines to make it easier to understand. This is standard procedure everywhere. It just makes life simple, and easy for the next person looking at it.

There are many, many more examples to see and learn. Many more than we could possibly add to this site. The above information is just to get your head wrapped around the general concept of motor control so that you don`t find it intimidating. It`s not. It is as simple as on or off.