Zack Hartle: Hi, welcome to this
video where we're going to talk about the differences between
Wye and Delta connected circuits. So of course, we know
that voltage and current and how they interact within either Wye
connected or Delta connected source or load play a huge
factor in the current and the voltage relationships. So I just
want to kind of do this video to compare the two, a little bit of
a cheat sheet for those relationships. So let's start
off talking about voltage. Alright, so voltage. Now this
could be an applied voltage from a source from an alternator or
generator, or this could be a voltage drop onto a load. So
these rules apply whether we're talking a source or whether
we're talking a load, they will be true. So looking at Wye over
here, now with Wye, we say this, this is our fundamental law, we
say that the line voltage is equal to the Phase voltage times
root three. Now what that means what's the difference? Okay?
Well, we have to remember when we're looking at this, this here
is called the Phase. So what would be you know, maybe a, b
and c to that star point or neutral, that will be considered
my Phase voltage. And going from here to here, that would be
considered my line. So that's typically line I like to think
of line as the conductors that are pulled inside the conduit or
the raceway or the cable, that would be my line current to my
line voltage measure between those two points, I like to
think the Phase as in the device in the in the alternator in the
load, right. So that's the voltage relationship there. Now,
what we see for voltage relationship in Delta is a
little bit different, we actually see that our line
voltage is always the exact same as our Phase voltage, because
again, what do we see, we see this here, that one winding or
that one load is considered the Phase? Well, our line is just
line to line. Electrically, those are exactly the same. So
if we were to take a voltmeter and measure our Phase, it would
be the exact same numbers if we were to measure our line whereas
on the Wye we will measure it perhaps 120 And then then on
line to line we would measure 240 So it's a root three
increase. So that would be our voltage relationships Okay,
great. Now, I want to talk about current and how current flows
into these circuits. Now, current on a Wye circuit is very
easy okay. What we say with current is that okay, if I
connect my you know, conductor to here, right, let's call this
my you know, my line conductor to hear whatever current is
flowing here on my face, because of kerchiefs current law only
has one point is also going to be flowing on my line. So, what
we see in a Wye circuit is we say that I line equals I Phase
that will be our relationship there. Now on Delta, it's a
little bit different. So, how I like to look at this for Delta
is I have my line conductor coming in okay. Now, current
works like this, we would have a line current here flowing on my
line conductor, go that eyeline now kerchiefs current law tells
us all current flowing into a point must also leave that same
point. So, if my line current is flowing in to that node on the
top, then my line current will are split and I will have Phase
currents flowing out from that point. So, these would be called
My I Phase in there. Now, the way that relationship works is
we say that our eyeline equals I Phase times again, we see that
root three relationship. And I just want to point out one thing
here for that is that this relationship there, eyeline
equals I Phase times three is only true in a balanced load or
in a balanced Delta circuit right? The voltage relationships true
and balanced or unbalanced, of course, a balanced circuit
meaning that each Phase has the same impedance In the same power
factor, that's what makes it balanced, same impedance, and
same power factor in each Phase. If they are balanced, my line
current will be my Phase current times root three. They are
unbalanced, you can check out the video I have linked below or
up top here, which will show you those relationships for
unbalanced current in a Delta circuit. Now, the last thing I
want to touch on here before we're done with this video is
just the the relationships on a phasor diagram. So in this case,
for a Wye circuit because eyeline equals I Phase, that's
going to be where that is. But the voltages on a phasor
diagram, V line will actually lead V Phase by 30 degrees. And
what we would see over here with our Delta, right, so that has to
do with the way those angles line up and again, I'll link
that video below to get more in depth into that relationship
over here, because our voltage is the same in the line in the
Phase, we actually have two current phasers on our phasor
diagram. And that relationship would be that eyeline lags I
Phase by 30 degrees on my phasor diagram. And again, one thing to
keep in mind again, that is only true in a balanced Delta. So
anyways, this is just kind of a quick comparison between the
two, my Wye relationships my Delta relationships, check out
this video here and playlist here. For more info on why check
out this video and playlists for more info on Delta. And thank
you so much for watching. Please like and subscribe and have a
great day
