 Hey, we're gonna talk today about what happens in a Y three phase circuit When you have an open in the line and you have no neutral attached now typically you'll have a neutral But there are situations when your wise configuration you might not have a neutral So we're gonna take a look at what happens to the voltage the current and specifically what happens to the power So let's do it up All right, just to give us some context here We have three phases coming in and you notice with the lightning bolts here. That's a broken line So what's gonna happen here is we have got three loads because we've got the resistors here connected in a Y Configuration and it looks like this line here will not be getting current to nor from it So let's start assigning some values to that All right, let's start with a 208 volt supply, which is pretty typical. We've got 10 ohm Resistive loads now with a broken line here the 10 ohms doesn't change So let's just make that one thing clear. I find that happens a lot when I discuss this stuff Some people think that oh, yeah, we don't have 10 ohms there anymore Well, 10 ohms is a physical property of the resistive element So it's gonna be there regardless of whether we have voltage or current or not Now here's where the trick happens Typically in a three phase circuit when you have a Y configuration your phase voltage is different than your line voltage So here's our phase voltage of 208 and typically in a three phase situation You would normally see a hundred and twenty volts here and a hundred and twenty volts here and a hundred and twenty volts here But we're no longer in a Y configuration basically for all intents and purposes This leg is useless. So what we end up having here is two hundred and eight volts from this line to this line Sorry, I'm not getting my lines working here this line to this line and What'll happen is it'll go down through here and because this is open It's gonna ignore it and it will go through these loads here So what we have is two resistors in series with each other So we are going to end up having and because they're equal resistances We're gonna get an equal volt drop across each one So we're gonna get a hundred and volts a hundred and four volts across this resistor and a hundred and four volts across this resistor So to figure out our current we have two hundred and eight volts We have ten ohms and we have ten ohms so and they're in series So we're gonna add them up together and we get 20 ohms total circuit resistance 208 volts divided by 20 ohms will give me 10.4 amps line current coming through here. We'll have 10.4 amps Now we can figure out what the power cross being dissipated across each load is a hundred and four volts times 10.4 amps means that each load will see 1082 watts of power And then I say what power is no matter if it's in series or parallel you can go ahead and add it up So each one of these is going to be a thousand and eighty two watts. So adding them up You're gonna end up with twenty one sixty three watts in this circuit So in this particular circuit, we're seeing that we are dissipating 2163 watts and again this one's dissipating zero watts because it has it's unopened at this point And so nothing will get through Now let's just for poops and giggles here say that this line wasn't broken I want to show it's something that's pretty interesting I find let's say that this line was good So I don't have it drawn there, but let's just pretend it is that would mean that I'm seeing 120 volts here 120 volts here and 120 volts here That would also mean that each phase is going to see 12 amps right because you know 120 divided by 10 gets 12 And then in a Y configuration your current line current and your phase current are the same So you're gonna have 12 amps up on that side, too So we figured out our voltage we figured out our current now We can figure out our power using this formula e phase times I phase times three equals power So we're gonna do that up and we're gonna see what we get We calculate that out one twenty times twelve times three Which is the formula for power in a three phase circuit gets us four thousand three hundred and twenty watts So with all three legs now we get four thousand three hundred and twenty watts when this leg was open We I got two thousand one hundred and sixty three watts So again, just to recap with a line break you get twenty one sixty three watts with no line break We're seeing forty three twenty watts, and if you do the math that works out to be Fifty percent of what it was before so with the line break in a Y configuration your power is going to drop by half And that's basically all that really has to go through it That's just kind of a walkthrough of why it's fifty percent We'll see that with a with a neutral situation you end up with sixty sixty six percent, but with a No neutral with a no neutral with no neutral we end up with fifty percent Hope that was useful as always if you're liking these videos Please do me a favor and hit the subscribe button down below it gets the word out Maybe hit that little notification bell because I try to release a video a week And you don't want to miss them all this electrical goodness if you're wanting some more information You're always welcome to go over to the electric Academy comm and if you ever need to reach out and get a hold of me I am always available on at Chad at the electric Academy comm stay classy, and we'll talk to you soon