 In this video, we're going to be discussing the current in a Y configuration, also known as the start configuration. So we're going to see how the line current and the phase current differ if they differ at all. Here I have a configuration drawn up. I have these are my windings. I have three windings here, probably called A, B, and C. On this side, I have a resistive load connected in a Y configuration. I know it's a Y configuration because it is 120 degrees out of phase each winding. So this winding here is 120 degrees out of phase with that winding, which is 120 degrees out of phase with that winding. Same thing goes for the resistive load. So I have a source that is providing three phase power, and I have a load that is taking three phase power. This line in the middle here, that's my neutral. And that's one of the joys of the Y configuration, because once we have that, we have access to two different voltages, 600, 347, 480, 277, 120, 208. There's just a myriad of different voltages available out there when you have a three phase system. If any of you watched any of my videos, you know what a fan I am of instantaneous polarity. I have now connected this guy up, and I have my instantaneous polarities. I have a positive here and a negative here, a positive on this side and a negative on that side, a positive on that side and a negative on that side. I'm saying that all these three points are positive. Now some of you peers are going to be telling me that it is not positive at the same time. I could not agree more. This positive happened first, then 120 degrees later. That positive happened 120 degrees later. That positive happens. Don't get too hung up on exactly when the positives happen. For simplicity's sake, we are just going to focus on the fact that these three are positive. You'll also notice that on this side I've got positive and negative, and on this side I've got negative positive, because we know that current flowing through a source flows from positive to negative, and through a load it flows from negative to positive. That's just the way it seems to go. If you look at my other videos I have on transformers, I get way more of a discussion on the source versus resistive load. What we're going to do is take a look at the direction of current right now. Let's say I've got current flowing from positive to negative. This current flows along and ends up going across this resistive load, negative to positive. Again, positive to negative from the source, negative to positive through the load. The same thing will fall true here. Positive to negative coming up along this line here, and then negative to positive. For our C phase here, positive to negative, kicking along old school, down here negative positive till we get to the star point. There we go. I've got the arrows denoting that, so it must be true because it's in a blue arrow. Now if you look at here, this is something that I'm just going to get a tiny bit into and get into much more later on in another video. I have the neutral current. This current flows along here, so let's just quickly talk about this. If this was say 5 amps coming that was being asked from the source, you'll see that it flows along. It's going to be 5 amps on the resistive load. Same thing at this point, if it's 5 amps being given, just following along because current stays the same in a series circuit, that resistive load is taking 5 amps. Our line, or phase, sorry, 5 amps there, stays the same as 5 on the line and then goes 5 again across this phase of the resistive load. Therefore, we can easily say that your I line is equal to your I phase in a Y configuration. Just to quickly talk about this neutral. What will happen is the currents will all converge at this star point and then you will have a neutral current that comes along here. Now not to confuse you too much, but if all these three are balanced, this neutral current here will be zero amps. If they are unbalanced, then the neutral will carry a current. Just doing what a neutral does. Its whole point is to carry that current and to be grounded, but we'll talk about that in the video on the balanced versus unbalanced neutral of a Y configuration. So to sum up again, in a Y configuration, your I line is equal to your I phase.