 so motor control. So I get the power circuit versus control circuit. What we have here is the power circuit. This is my motor. This is what we're trying to run. And I'm just going to walk through each one of these items is. This right here is my disconnect. So that's what we are going to use to open or close the switch to provide power. The disconnect has to be horsepower rated because this motor here draws horsepower. It's an inductor. It's going to be some arcing and sparking. It could draw a ton of current when it's starting. So this disconnect here if you're opening it under load has to be able to handle the arc that's going to come across the contact there. So disconnect always has to be horsepower rated. On this side we have the fuse which hopefully by now you would understand is there to protect the wire so the wire doesn't catch on fire if this motor starts to draw too much current. So the fuses are current rated. Here we have what we call our power contacts and these guys are controlled from the control circuit. So I'll get into that in a second here but these guys too have to be horsepower rated because it is these guys that are going to be starting and stopping the motor. This we just close the switch. Power comes through. These will be normally open as these contacts are. But then something tells these guys to close and lets the power through. Same thing when we stop these guys open. So when this motor stops these contacts here will open and the motor will stop running. So again horsepower rated. Coming down the line here we have our overload heaters and this again they are attached to the control circuit as well. There's different kinds. There's the solder pot. There's solid state. There's bimetallic strip. I'll have another video in my lesson on motor control on the differences between overloads and what they're really so very important. So I'll talk about overload versus overcurrent at another time. And then we have a motor. So that's our basic power circuit. And this is three phase power. That's why we have three lines here. So I have line 1, line 2, line 3 goes through a disconnect switch. Sometimes the disconnect switch will actually sometimes all of this will be in one cabinet. We call that a combination starter. Again more in the lesson. This is our basic control circuit. This is what we call a three-wire control. I've got a lesson on the difference between a two-wire versus three-wire control. Spoiler alert. It's this holding contact here. But again this power comes through, goes through the stop which is normally closed. Comes to the normally open push button. We push that down. M coil. That's not the motor. That is a coil energizes. Goes through the overloads and up at the same time that M coil energizes. These contacts here close and it holds in. So that if I let go of the start button this will go all the way through. And I'm good to go. So we have our power circuit up top. We have our control circuit here. Now these two guys have to link somehow. And there's two ways we can do that. This generally where we get our power from for the control circuit is off the power circuit. There's two ways we can do that. We can do either full voltage control or use a control transformer. So let me show you what I'm talking about. Here's full voltage control. So let's say that this is like 120, 120, 120 and this control circuit down here is going to be 208 volts. Pretty standard. You'd have this coming between these two lines here. You have 208 volts. The difference is or not the difference. The thing you have to make sure is that this coil can handle 208 volts which is possible. But what I would suggest is probably doing this is throwing a control transformer. So if you have 208 volts or even if say you've got 600 volts here you can step that voltage down to like 120. You can go down to 24, 12 volts. So that's what we put the control transformer. So if you open up a combination starter oftentimes you're going to see a control transformer in there. So that's where we get the power from. We take the power from the power circuit over to the control circuit. And so they're all interlinked. Now we grab it off of any two lines after these fuses. We do it after the fuses because we want to make sure that this control transformer is protected. If it shorts it'll blow one of these two fuses. There we go. Now we want it after the fuses but not after the contacts because these contacts are normally open. If we had the power after then the power would never get through because we need this guy to close that guy so it just wouldn't work. Alright. Now I talked about how these guys are connected. These overload heaters here are actually like a bimetallic stripper solder pot. They're physically attached to these overload contacts down here. So if the heaters open up like if these guys trip then it's going to open up these normally closed contacts in the control circuit and the whole circuit shuts down. This M-coil de-energizes everything shuts down. Same thing. If this M-coil energizes and I believe I did a little video on my on the forward reverse last week and I talked a little bit about this but if this energizes these contacts here will close. Okay. So that's how we close these contacts. So if we push this down this energizes these clothes and the actual motor starts. Now again I cannot stress enough this is the motor this is the M-coil the contact and I'll show you what I'm talking about in a second. At the same time too we have a set of auxiliary contacts for the control circuit so that we can hold it in so that when I let go of this push button this will still run. Okay. Now just to show you a couple different starters. This is a NEMA starter so it's a bit more robust used in North America. We're seeing a lot more of this kind of going away but basically you're bringing your three lines in on the top three lines out on the bottom so you have your L1, L2, L3 coming in there and then on this side you have T1, T2, T3 running off to the motor. This is where your overloads will go. There's your overload reset switch and in here is your coil and probably one of a few of these that have to really look at the name plate but this will be your holding contacts up here. Probably these two. Actually this will be your coil and your holding contacts will probably be somewhere up in this area. Right down here this would be your normally closed contacts for your overloads. You're seeing more and more of this style. This is IEC which is a European style. They're smaller and more compact not as robust but they're generally in motor control stations anyways. So you've got the same thing. You've got line 1, line 2, line sorry line 1, line 2, line 3. Here's your normally open contact. Here's your other normally side of the normally open contact and over here you've got your overloads and down here if you can read it T1, T2, T3.