 In this video, we're going to be walking through how to calculate out the number of wires in a four-way switching circuit. Now let me show you what I mean. So here we have a situation where we have two lights. I have this light here and this light here. I have three different switching locations. I have three-way switch number two here, three-way switch number one here, a four-way switch over here, and a receptacle down below there. And we have what's called the home run over here. This is not a very practical circuit. This is an FYI. You would probably not lay out your circuit like this at all, but let's just say somebody went ahead and ran pipe from these situations from this three-way switch up to that light between the two lights down to this other three-way switch and into this four-way switch and down to the receptacle. And it's up to us to determine how many wires are going to go into each pipe. We're going to do that, and we're going to show you how to do that. So our first step is to draw out a schematic, which shows electrically how the circuit works. Here is our schematic. So whenever we have three-way switches, we always have two three-way switches. We'll have one three-way switch on one side, which will go from the hot to a common. Then from the, through the switch to a traveler, or a traveler on that side, then on the other three-way switch, same thing, travelers, common, common to the lights, lights to the neutral. Throwing in a four-way switch is basically you're going in between the two three-way switches. So you're throwing a four-way switch in here, and they only have traveler terminals. You do not have common terminals. If I wanted to switch from more than three locations, I would just throw another four-way switch in here and another four-way switch if I wanted to switch from another one. So a schematic for these will always have three-way switches at one side and the other. And then if you want to switch from more than two locations, you just throw four ways in between. Now what we're going to do next up is we're going to go ahead and number our circuit out. So in order to do that, I'm just going to get my pen tool out here and we're going to start with, on this side with our hot. So we're going to number that one. Anything that is associated with that wire or touches that wire, we're going to say is one. So if we go down here, this would be one as well, and on this side of the receptacle is one. After that, you see that we've got a break. So we've got a break here in the switch. So we're going to change numbers. So on this side, we're going to go with a two and a two because that's attached. Then we're going to go three and a three because that's attached. Down here, we're going to go four, four, four on this side because we have the lights in the way. We changed the numbers. Five, five, five up top. Then that's all the way down to this receptacle here is another five. We still have two more wires to look at here. So we'll just move up on our numbers to six and six and seven and seven. We now have all the wires numbered up. This is such an important step. Get used to numbering your circuits out. It is a, it's a skill that you'll use in motor control. It's a skill that you use in laying out circuits. It is very, very handy. So what we're going to do now is we're going to take this drawing here, this schematic drawing with the numbers and I'm going to place it beside our actual wiring diagram from the previous picture. So here we go. Now we have our schematic which shows how the circuit works electrically and what's going to become our wiring diagram here, which is how it's physically laid out. What we do next is we're going to take these numbers that we've worked onto our schematic and we're going to apply them to the physical elements on the wiring diagram. So we're going to take my pen tool here again and one in five, one here and five here is my home run. That is my main power coming in one and five. Three-way switch number two. Well, if I look here on my drawing, I've got three-way switch number one, three-way switch number two. Three-way switch number two is going to have three, four and seven attached to it. So we're just going to write that down beside our three-way switch, three, four and seven. Three-way switch number one, which is right here, is this one over here. It is one, two and six. So I'm going to transfer those numbers over as well, one, two and six. Our four-way switch is in between the two and it has the numbers two, three, six and seven. So I'm going to write that beside the four-way switch here, two, three, six and seven. And then last and not least is we have a receptacle down at the bottom here. So we have this receptacle is the same receptacle here. So that's a one and a five. So one and five. So now we've got ahead and we've got all our devices and switches except for our lights. If we look at our lights over here, our lights are numbered four and five and four and five. So we'll apply those to the lights themselves. So this would be four and five and this would be four and five. So we now have everything numbered up and labeled. What we're going to do next is we're going to change the color of our pen just to make it easier to follow along. I'm going to write out I have seven wires in total. So I'm going to just put a numbered list here, three, four, five, six and seven. Just making some room here. I'll show you why that's important right now. What we're going to do is we're going to basically kind of play connect the dots. I have a one right here and I've got to look for wherever else I have a one. I have a one down here and I have a one down here, which means I need to take a one from this point down to here as well as down to here. So we're going to put that in as our numbers, as our wires. So we've got a one here, we've got to take it through there, down to there. We also have to go through this three way switch and down to there. And then I just number it beside it just so I know that I've covered it one one and I'm going to give it a check mark. So I have that all figured out. Next up, I'm going to go to, so I look for my twos. I've got a two here and I've got a two at the four way switch. I don't have to end twos anywhere else. So I'm just going to put my twos in. So I have a two here to there and that's it. That's the only two that exists. Next up is three. I have a three here. I have a three here and I have no other three. So I have to get to get three wire from there, number three wire from this point down to this point. So I'm going to put in my numbers again. So I've got a three, three, three, three. So I've got three there, three there, three there, three there. So I have all of the threes put together. So I've got two taken care of, threes taken care of, four. I have a four at the lights, four here and a four here. And I also have a four at three way switch, number two down here. So I'm just going to go from four to four and four to four. So I'm connecting all of them together, five. I've got a five here, a five here, a five here. And it looks like I have a five down at the bottom here. So I've got to take a five to this light, to this light and all the way through down to this receptacle. So I've got a five here, I've got a five here, I've got to take a five through here and a five through here and a five through there. And that takes care of my four and my five, six. I look for the sixes that I have. I have no six, no six, no six. I don't have a six there. I do have a six there and I do have a six at my four way. So I'm going to go ahead and just take it through from there to there. That's six and I don't have any other sixes. So that takes care of my six. And finally we come to seven. So I take seven and I look at seven and say, okay, I've got a seven here at the four way and I've got a seven down over at this three way, but I don't have any other sevens. Seven through here, up here, through here and down to there. So if I do that, starting here, I've got my seven, I've got a seven, I've got a seven and I've got a seven. I check that off and it looks to me like we're done. So the way I look at it now is I can count these up and I can say, okay, on this wire from the home run, right here, I've got two wires, so I'm just going to write that in. I'll go with a nice black here. So I've got two wires there between the two lights. I've got one, two, three, four, five wires, five wires there between the light and three way switch. Number two, I've got three wires between the light and three way switch. Number one, I've got four wires between three way switch number one and four way switch. I've got one, two, three, four, five, six wires. And then down here, I have two wires. And that basically takes care of the entire circuit. And that's how we do this. So it just shows how very important it is to determine your schematic, number your schematic, then transfer your numbers over to the physical and then basically play connect the dots after that.