What up? Everybody? Welcome to another episode of Let's Ask Paul, the
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we're going to continue to answer those questions for you. So that's another resource
that you can use. Okay, So today I want to talk a little
bit about some basic fundamentals that you know, people struggle with, not just
for electrical exams, but in real life. And we'll kind of talk about
a little bit of real life scenarios when it comes to things like Ohlms Law
series and parallels in the concepts and what you need to learn, the basics,
some of the rules, some rules you got to follow. Now,
I will say that, for example, a voltage drop. For those that
are listening to this podcast, we have released two pocket wallet voltage drop.
Well I shouldn't say two. It's a card that you can keep in your
wallet so that you don't have to remember voltage drop. Again. Remember,
voltage drop, for example, is only required in things like sensitive electronic equipment,
uh and also in fire pump applications. And they're they are not the
three percent and five percent overall that we're familiar with with the informational notes in
to ten uh, to fifteen and to thirty right, the voluntarily telling you
not to exceed three percent on the branch, that type of thing. So
these these are voluntary, whereas in sensitive electronic equipment as well as with fire
pumps, it's a mandatory thing to take voltage drop into consideration come for the
reliability of those circuits involved and whatnot. And you would think that voltage drop,
because of that nature, would be more serious in the code in sense
of not being optional or a voluntary thing under an informational note. You would
think it would be something that would be worked by now into the code.
And the reason really that people don't jump in clamor to getting that into the
code is that you know, for motors, for example, motors have overloads,
and so again you've got short circuit ground fault protection UH requirements and in
four thirty dot fifty two requirements for sizing, but then you have the overload
requirement for thirty thirty two that your circuits are pretty well protected, right,
and the motor's pretty well protected. So that's the only one you know,
for example, they say, well, voltas drop can affect motors, Now
it can, uh, And having a voltage that drops below the you know,
the the operating range can cause the motor to prematurely heat up or shut
down with the overloads, and that becomes a problem, a bigger nuisance problem,
but it probably could you know, wear on the life of that motor.
So people want to take voltas drop into you know, into consideration in
their design, whether or not it's required or not. And then of course
you hear everybody talk about voltage drop. Oh, I'm running Noma tallashed cable
across this long run or these use little mega mansions that I see where they
run these fourteen twos and twelve twos, you know, one hundred and fifty
two hundred and fifty feet before they even hit the first outlet box. So
voltus drop is a very serious issue to take into consideration. But it's not
in the code as a requirement, and I know people say it should be,
and I encourage all you out there to submit your public inputs for that,
and your next opportunity for that's going to probably be around twenty twenty seven
when we're start working on the twenty twenty nine, hopefully they start working on
it. Hopefully I'm retired by then, but who knows. So at the
end of the day, you know, we we have those cards available that
are fit in your wallet that cover how to size the circular mill, how
to size the maximum length and all that, and it even explains to you
how to calculate the exact k which you really don't need to worry about,
you know, you just just follow what's on the card. You don't have
to worry about it. But hey, if you want to know, I
do always try to educate. So that's Those cards are available over on our
website. Pick up one. I think they're five ninety nine and that includes
shipping, so you know, it's basically just the cost of producing them,
the material and the time, and the shipping's already built in. So check
them out over at fasttracksystem dot com if you're interested in getting one of those
for your wallet. Okay, let's talk a little bit about Ohm's law.
I'm sure you all are familiar with Ohms law and the concepts of Ohlms laws.
The rate of the flow of the current is equal to the electromotive force
divided by the resistance. Okay, So in most of your OWMS wheels,
and not all of them, people can get creative in the nomenclature they use
of an omes wheel. But typically in most of your basic fundamental formulas for
the OHMS wheel uses I as the intensity of current, which is what we're
going to refer to as ampeers or amps. E is the electromotive force.
E on our OHMS wheels refers to vaults. So again some of the OHMS
wheels that as you see from people, they'll actually use v instead of E.
But you know, either way, you might see it either way.
Just once you're familiar with the you know the formula flow, it doesn't really
matter. R is resistance and that ends in OHMS. And then of course
P is power, which again is watts. Right. So the basic formula
that you get that you start off with when you're wanting to learn something like
OHMS law uh, and it'll serve you well because I mean you could be
doing and I'll give you an example of a practical calculation or a practical aspect
to it, and then I'll talk about how this may come into play in
a in a dwelling or something or a building you know, in commercial the
engineers probably take care of it for you, but in residential, you know,
that's you know, you got to think about it a little bit.
Especially now. It's less today with the LEDs that we're installing, but it's
still something you have to take into consideration when you're laying out your circuits and
things like that for the lighting, for example. So your basic three formulas
is, if you want to solve for I, which is uh intensity of
current which is ampiers, then it would be just E, which is the
voltage, divided by R, which is the ohms. Now, if you
want to solve for R, which is the ohms, then you have to
have the E which is the voltage, and you have to have the I
which is the current. And if you want to solve for E which is
the voltage, it's simply E equals I times R. So depending on what
you have or what you're trying to solve for, right is you know,
if I know what the voltage is and I'm trying to solve what the amps.
If I know what the voltage is and I know what the resistance is,
then it's simply E divided by R. Pretty straightforward, right, And
good news is for those that are on an electrical exam, typically they give
you an omes wheel prior to your test. But some of these formulas are
pretty simple to remember in your head because in this case, the basic Gold's
law is the three dimensions. Here we're not even incorporating power into this yet.
We're just talking about E, R, an I. Right. So
to solve for E, you know you have an E and an R left.
If you're solving for R, you know you have it E and an
I. If you're solving for E, you know you have I, N
and R. The only thing you got to remember is when you're doing for
I and R, which is vult which is ampeers and resistance and ohms.
Then it's division. Okay, it's E divided by R, E divided by
I. If you're solving for voltage, you got to remember its multiplication.
It's I. Times are okay. Now, these are easy things that you
can just write down in your code book. If you're in some states that
allow you to write things in your codebook, or if you're in the field,
you can jot these things down. And we also will have a card
coming out pocket wallet card that will have the Ohms law, the owns law
wheel, and a bunch of the formulas on it to make it easier in
the field. It's just a pocket handy little deal that's coming next. Right
now, we only have the voltas drop on, but we will we will
get the other one in there for you, and these will be made available
in a series so you can get all of them at once and there'll be
a nifty little holder that you can put it in. But anyway, or
maybe you don't need it, maybe you just memorize it and you're good.
You're good to go. So those are your basic three formulas that we work
with. When you're talking about basic Gomes law formula. If I had to
give you an examine, now let's let's let's mix in the same scenario that
comes for examp ample when it comes to power, right, so power watts
is the same same example we can mix. We can mix this into the
mix because for power you have E times I is going to give you watts
power right. Uh. But if you know what the resistance is and ohms
and you know what the current is, then you can also go are times
I squared right, So it's basically the current in ampiers squared times are and
that'll give you watts as well. Uh. And then also if you don't
if you're trying to search for watts and all you have is the the voltage
and all you have is a resistance, then you can go the voltage squared
divided by are the resistance. So there's there's quite an additional formulas that you
can do for watts. Uh, finding out what the watts of power is
to using the same concept. Okay, so let's kind of run some examples
so you can so you can get an understanding of what we're doing with it.
So let's just say we have an example, and we have an appliance
that's twelve hundred watts and again traditionally we're going to be connecting one hundred and
twenty volt circuit to it. Right, what do we know? We know
the watts and we know the vaults. So if you were to look at
at omeswheel at this point, is what are we trying to solve for a
Well, we don't know what we're trying to solve for the amps, right,
And so if you look at it and the variables that you know,
and you can say, okay, well, how do I solve the amps.
Well, if you solve the amps and can go okay, well to
solve it, I can go P over E and that's going to equal I.
Okay, So very very same way we did the voltage over resistance to
get here. It's the power divided by the voltage will give us I.
Right, So which is the ampiers we're searching for? So it's simply twelve
hundred divided by one twenty. That's ten ampiers. Okay. Now remember now
that we have all of these variables involved, then we kind of think,
okay, well, how do we find out what the resistance is? Because
all you gave me was the ohms. We have lots of power, we
have voltage, and now we have the amps of the circuit. So what's
the one thing missing? Well, what if I want to know or we're
asked, well, let me tell me what's the resistance in oms? Well
that's easy because now that we have the amp value, we can go back
to the original formula, which is our resistance equals E divided by I or
voltage divided by the amperage. So now it's one twenty was the volts divided
by ten, which was the ams we just calculated it and that equals what
twelve homes. So the key thing to remember about Ohms law is the ability
to be able to work any of the equations out right. And I'm gonna
show you some other ways to do this using the different formulas that are in
your owns wheel, right in our Ohms wheel. It is a great thing
to get used to to have, and it's also great to have that in
your pocket as well. So obviously we'll be coming out with a nice little
Ohms Wheel pocket edition wallet sized card and that'd be pretty cool. Okay,
So let's kind of use those numbers since we're just kind of working numbers,
and see how it owns wheel, and see which of the Ohms wheel formula
that we would use. And granted you can't see this as the podcast,
so I will describe the formula for this and then it'll it'll make much more
sense. So let's keep the variables that we already have. We already know
that it was ten amps, we already know it's one hundred and twenty volts.
We already calculated out the resistance for that is twelve omes, and we
know that the wattage was twelve hundred watts. Okay, So using these numbers,
depending on what's missing, we can show you how you use the formulas
to solve any of this. So if you had any of these that at
least two of these, then you can solve for something. So let's talk
about the amps. Let's find the amps. So let's ignore the fact that
we already know what the amps are. What we know is one of the
processes of the formulas that we can use is the one for amps where it
says that it's a square root of power divided by the olms. Okay,
well that's the So you're going to solve the watts divided by omes first before
you do the square root, right. So if you ever see that that
way where you have the square root over and then in the middle of it,
underneath it you have the actual the omes I mean, excuse me,
the watts and it shows a line and the underneath it is the omes.
You want to work that first. So one of the formulas is the square
root of watts divided by omes. Okay, well it was twelve hundred watts
and the resistance was twelve ohms, so we divide twelve thousand. Excuse me,
it's twelve thousand watts divided by twelve omes, right, and that gives
us one hundred. Then you just hit your square root key on your calculator
and that is ten, right, So that would be ten ampiers. Well,
there's another way to solve it. If we already know the wattage and
we already know the voltage, then remember one of the other formulas for solving
amps is simply what is dividing the watts into the voltage, and that works
the same way. So P divided into e, so it's twelve hundred divided
into twelve. Excuse me, twelve hundred divided into one hundred and twenty.
That's the voltage. That equals ten ams. But there's also another way that
we can solve amps. If we know the volts and we know the ohms,
then it's one hundred and twenty volts divided into the omes, which will
be one hundred and twenty divided into twelve, and that's ten amps. So
the three formulas that we use here to solve for amps, depending on what
we have in our equation, is that we have to have at least two
to work it out. And then once we do that, we open up
the doors for, you know, to other aspects of the calculation, depending
on what we're working it out as So, the square root of P over
R we were solving for I, then that was twelve hundred divided by twelve,
which is one hundred. The square root of that is ten amps,
so it's ten amps circuit. The other one was the watt eye equals power
or the watts divided by voltage. That was the one to twelve hundred divided
by one twenty. That's ten amps. And then of course we have the
other searching for the amps. If we know what the voltage is and we
know what the omes are, then it's just one hundred and twenty volts divided
by twelve omes, and that is ten amps as well. So it's pretty
straightforward solving for the amps. And with all the variables that we have in
play now when it comes to wattage, it's essentially the same thing. The
three formulas that we use to solve for wattage is the first one is is
the voltage squared divided by the omes. Right, So if it's a same
scenario, if it's one hundred and twenty volts and it's twelve ohms. Then
it's just one hundred and twenty volts squared, okay, So basically one hundred
and twenty times one twenty okay, and which is fourteen thy four hundred.
Think about that when you see one hundred and twenty squared, it's just one
hundred and twenty times one hundred and twenty. That's all it is, all
right, So fourteen hundred and fourteen thousand, four hundred, and then you
divide that by twelve, because twelve would be the oms of resistance that gives
you twelve hundred watts. So we can find the watts. As long as
we know the voltage and we know the resistance, we can find wattage.
Another way to do that formula is the simple formula that P equals E times
I. And in this case you're going to use the formula that you have
the answers. In other words, the data that they give you in the
question is what you're going to determine which formula you use. So if we
are given the voltage and we're given the amps, then we're going to use
the formula where pe wattage equals volts times amps. So in that case is
just one twenty times ten. That's twelve hundred watts. Now, maybe they
only give you the voltage. Excuse me, maybe they only give you the
amperage, and maybe they only give you the oms. Okay, well we
can solve it that way too, the amps, and so in our case
it's ten amps, so it's ten amps squared. Okay, So ten amps
times ten amps is one hundred times twelve and that is twelve hundred watts.
So again my point here is you just simply you're going to learn the different
formulas and you work with what you have. Now, maybe they give you
what you need to do in order to be able to get another equation.
Maybe they don't give you the amps, but they give you everything to solve
for amps. And then once you solve the amps, then you open up
the door to be able to do other calculations. Define the answer right,
and so the next one is vaults volts is the same way as we kind
of did for amps. The vaults. One of the ways to solve this.
If they give you the wattage, then it is wattage times resistance in
this case is twelve hundred watts times twelve ohms of resistance. So you do
the wattage times the resistance, right, and that'll give you a total of
twelve hundred times twelve, and that's fourteen thousand, four hundred, and then
it's the square root of that. So in our case it'll be twelve hundred
times twelve is fourteen four hundred. The square root of that is one hundred
and twenty vaults, and that's what our voltage is. Now. Of course,
if they give you the amps and the ohms in our case ten amps,
and they give you the ohms of resistance in our case it was twelve
ohms, then to solve for voltage, one of the equations is just I
times are so ten times twelve is one twenty. Or maybe they give you
one where it gives you the watts and it gives you the amps, and
so okay, so it doesn't give me the resistance, but it does give
me the wattage and it does give me the amps. So I can use
the formula P divided by I to solve free. So P being twelve hundred,
that's the watts divided by ten being the amps is one twenty, and
to round this out the ohms. It's essentially the same way as the wattage
were done, makes sense, right, So find the resistance. If I
know what the voltage is one hundred and twenty volts, and I know what
the wattage is twelve hundred watts, then I can solve for resistance by going
voltage squared divided by twelve hundred, which is the wattage. So it's E
squared divided by P, which is the watts. So that would be one
hundred and twenty squared. And we already know what that is, one hundred
and twenty squared, So one twenty times one twenty is fourteen thousand, four
hundred, and then you simply divide that by the wattage which was twelve hundred
watts, so't divide that by twelve hundred and that is twelve That is the
oms. So they could ask you the question when they say, well,
we want to solve for the resistance in OHMS, and we'll tell you the
amps and we'll tell you what the wattage is. Right, Okay, So
they didn't tell us what the voltage is, but we don't need it.
We have enough variables to solve it out. So in this in this scenario,
it would be you know our equals P the watts divided by amps squared,
right, So it'll be twelve hundred watts divided by ten which was the
amps squared. So all you do is do the ten squared first. Ten
times ten is one hundred, right, and so then you got the the
twelve hundred divided by one hundred, and that is twelve ohms. Makes sense.
And then lastly it's if you're given the vaults and you're giving the amps,
then it's just easy, right. It's just a normal traditional equation that
we did E over I, right, So it's simply one twenty is the
E which is the voltage, divided by ten, which is the amps.
And so with your calculator you just do one twenty divided by ten and that
is twelve and that is it twelve ohms. So trying not to make it
is, you know, is very complicated, because it's it's not complicated one,
it's it's helpful if you have the formulas. So the whole point of
this episode is not to expect you to listen to it and understand the Ohms
law process. By remembering what I talk about in a problem. What I
mean is go and see if your state allows you to mark these in your
codebook, right, and if they do, then you want to put all
of these formulas in your codebook, typically up near the front where you have
the code panel members, because you got a bunch of area to write.
There's blank spaces there. That's the best place to do it, and that
just gives you the greater opportunity to be able to have it right there,
handy for you. If you're in a location that does not allow you to
write in your codebook, then just remember some of the fundamentals. Go over
listening again, reviewer owns wheel, your power wheel. Learn these different formulas
and then it'll make sense to you as you get into it. But it's
the low hanging fruit on an electrical exam where they ask you something and it
may seem like it's complicated because they might say you have two light bulbs and
nobody uses that terminology anymore, it's lamps. But you get it. They
might say that's two hundred watt light bulbs, and so that's two hundred watts
of load, and okay, you can solve it because now we know what
the wattage is and they'll tell you what the circuit is if it's one hundred
and twenty old circuit. So you have the foundation to be able to calculate
it out. And you may think, well, I'll never have an owns
law situation in my career, but you may on an exam. You very
male could. And so that's the reason why we brought that up today.
Now, in the real world, when would you run into needing this as
far as understanding what the ams are and all that. Well, you know
what if you have a lot of lumin airs that you're putting on a circuit
and have a specific load. And this was a bigger deal back when we
had normal incandescent and things like that. We had to worry about our loads.
Not so much now with the LEDs and the you know, the CFLs
and all these really low wattage loads, it's not as critical. But understanding
owns law is a foundation that electricians have to go through. Whether you're an
apprentice, helper, even a journeyman striving to be a master. These are
fundamentals and we just always and we forget them. You know. It's one
of those things whereas you don't use it, you lose it. So you
just kind of got to go back through and refresh your memory, kind of
get another feel again for these formulas and things like that. Rest asshured,
folks, if you want that quick and easy in your pocket. We will
be coming out with the Ohms Law wheel and the formulas. One side will
be the wheel, the other side will be of the various formulas and examples.
That'll be a nice little pocket edition, So look for that soon over
on fasttracksystem dot com and check that out. Okay, all right, that's
going to be all for today's episode. Just time to talking about Ohm's law
in those scenarios. I do have a podcast coming up that we'll be talking
about the basics of series and parallels and combination circuits and just kind of since
this is kind of one of those things that are really hard to do over
a podcast, it would just be a casual conversation talking about them with the
understanding that you will need to do a little bit of extra study. We
do have videos on this over on fast tracks Tube series and parallels and all
that kind of stuff, and we even have some recordings from our Wednesday night
sessions that are available up there that you could you can watch. And again
we go a little deeper into it and that type of thing. So all
right, all right, folks, hopefully got something out of today's episode.
I didn't bory to death. Who knows if you'll listen to an entire ohms
Law podcast, but hopefully you will. Till next time, folks, stay
safe, God bless and oh, by the way, drop me a note
telling me you listened to this whole thing. That'd be awesome. Take care,
both taskball boot both ask nothing maskea nothing bo