All right so now we're going to do a review of some of the basic electrical terms that were reviewed last class. Let's start with two of the most misunderstood, so we'll start with the most misunderstood word in our trade. I don't know if it's the most, but it's pretty close to it, probably right up there with freon, it's being a misunderstood word so short, what does that mean? I'm doing something it's doing something that it ain't supposed to be doing. Let's give some examples of what a short could be, what are some of the most common shorts in our industry? No, no, why you're, not tightening down, isn't the short bare wire touch touching ground, a bare wire touching ground? Yes, that is an example and what will be the result of a bare wire touching ground, what energized well you're, going to have a path between energized circuit and ground and, generally speaking, if there is a ground path back to the other side of the power source, Then you're going to have high current and high current should result in what blow infused trip breaker right, something shutting off and again that's something happening that ain't supposed to be happening right.

That's what shorts induce! What are some other examples of a short you stole my film, you sold your thunder yeah another one that we talked about was was matthew's example of having two current carrying conductors that cross. We generally call that a short there are some people who call it different things, cross circuits or whatever, but we still generally call it a short and so in general, a short is an undesigned path either to ground or to the other side of the of the Of the power supply that it came from so in the case of a battery i mean the the best way to describe a short. Is you got a battery and there's a path between here and here that's a short. We all know that, but is it a short if we got a wire coming from our battery? That's just broken.

Is that a short? No, that's an open right, so this guy right here is called an open if there's a break and a wire. So an example of a of a wire not being tightened down good enough that can result in heat. At that point, that's what happens if you don't tighten down the connector correctly, there's resistance in that connection and that will result in heat which could result in a short which could result in an open, possibly but generally speaking, if that wire burns off and disconnects, is That a shorter and open it's an open right now, because you have open, you have an open space right. It's important that we don't get those two things confused and we don't need to go much more in depth than that, then just for you to always think.

Oh, i said it's a short, but is it really a short because if you don't understand the distinction you're going to grab things like your short pro tool in order to find a short when you don't have a short you've got an open and you'll? Look in the wrong place, so it is important to know the difference. So that's short and open got to know the difference between that. What about this? If something says n, o versus n c, what does that mean? Normally open versus normally closed? So if something is normally open, what does that mean when there's no power applied to the coil or whatever energizes it? It's open? If you just start with it with an ohm meter like we did uh last class, and you take your own meter and you measure across a set of contacts, it's normally open and those are drawn like this. That is a set of normally open contacts.

This is a normally open switch, it's normally open and open means current will flow or it won't flow. It won't flow. It's like an open draw bridge. That's the best way.

We can explain it, don't get it confused with an open, faucet or an open door, because an open foster an open door. Things do move through. That's why we use the drawbridge example right, so open means no path, which means no current flow, no electrons. Moving normally closed, we draw it like this or a normally closed switch.

We draw it like this, we draw it showing it closed, makes sense. Go ahead. I don't know why i'll just use your lights for an example for open and close my lights. Yeah closed wrong.

Open they're off yeah, that's what you just did. The lights are a good example. Yeah, you don't like the drawbar, you don't like the drawbridge all right. Let the record uh reflect that nicholas.

Does not like the drawbridge metaphor. Okay, let it be written. Let it be done when we say make or break what does that mean, makes a path or breaks a path. So if i say something like, i want you to break the r circuit or the hot circuit, with a float switch that is normally closed.

What does that mean? I want you to break the r circuit with a float switch. That is normally closed. What does that mean? You activate the point switch well, it just means that when you wire it to the power, someone has to go through the wiring right. When you wire it so say, i have a red circuit here, so this is a r circuit and i've got a float switch we'll just we'll draw a float switch like this.

It's normally closed, we'll draw a float on it. I want to break this r circuit, so we got an r, an r here and we'll pretend we got wire nuts here and we're going to break it. If this switch goes open, it's normally closed, meaning if it ain't full of water. It stays closed.

So normally it's closed, but if you fill it with water, it goes open and it breaks the circuit. Once we get the water out of the switch, then it makes the circuit makes just means closed. Brake means open, brake means ain't, no current flowing make means circuit is intact. Current can flow again.

It's like a drawbridge. No okay, it's like a light switch when you flip the light switch on. Are you making or breaking the circuit you're making the circuit the lights? Come on flip flip, the light switch off. You are stopping yourself right, you're hitting your head you're breaking things.

Yes, because you cannot see anything. I like. We have very literal people here, and i appreciate the heck out of you for that. So we already showed most common contacts.

Let's talk about what open on rise looks like okay in terms of a switch. We didn't cover this, but i think this is also valuable if i draw a switch and we're going to say that it is a pressure switch. That's what a pressure switch looks like. You know why this is i'm really bad at drawing okay, so we're just going to live with it, though this is a bell and or or it represents a bellows right, and so, if i apply or a diaphragm, i don't know why.

I said a bellows. It represents a diaphragm. If i pressure to this, it will open the switch. So is this a close, because now we know what close means right did i cover close, so close is make open his break.

Let's write that down here, close equals, make open equals break. We're going to say that this is a normally closed switch. I didn't quite draw it right on the pole, but that look. That is normally closed, which we would say nc right.

So is this a open on rise, switch or an open on fall, switch open on rise right makes sense if this little guy here travels this way it's going to open right, but if it's an open on rise, then it is a close on all right. So we can say it either way open on rise, close on fall. Now you would generally say open on rise when it's normally closed. That makes sense.

When it's normally closed, then you would say it opens on rise. You wouldn't call it a close on fall when it's normally closed, because it's already closed what type of switch would you see in a typical air conditioning system? I'm really going to stretch you here. Your deductive reasoning, you're going to be sherlock holmes is up in here. What type of switch in a normal air conditioner would be a open on rise pressure, switch high pressure, switch high pressure switch because again, this is specifically a pressure switch, so you're not wrong, but a float switch, isn't really a pressure switch.

It's a float switch specifically. Let's do one that is a temperature activated, switch and you'll see these. These are real. These are real you're learning how to read diagrams as we go.

This is a open on rise temperature switch thermal switch thermal would be a better way of saying it than temperatures. Not really because your sensing bulb isn't a switch, it's not electrical! You know! That's a in there, oh okay, you're, reversing that i can. I could see that i could well again a reversing valve it's actually on the refrigerator side we're this is we're dealing with electrical here, so focus on electrical. So what would open? What is a safety that opens on a rise in temperature? Thermal overload on a motor right: this is how you would draw a thermal overload on a motor or one way you could.

This could also be a high limit on a furnace when the temperature gets too high. It opens what happens if we draw it. The other way, what happens if we draw it like this as close on rise, what kind pressure switch close on rise pressure switch? So let's say you wanted to create an alarm that would go off and you know turn on a siren or a bell when pressure got too high on something you could wire it through a close-on-rise pressure switch to me well, no, in the case of it, i Wasn't thinking of pressure, i was just thinking, it rises up and then it cuts it off yeah, but but that would be the opposite, because that would rise it up and break the circuit right rather than making this this rises up and makes a circuit closes. The circuit, once it rises now, i'm going to add one more thing to it and then we're going to be done with this, because this is another thing i didn't introduce.

But while we're on the you know, while we're on the you know we're kind of feeling it right now, don't you think that you're kind of feeling it right now all right? This is called a s. P s t anybody know what that is, pole single, throw switch. So you have your poles and you have your throws slow, that down all right single pole single, throw now a pole is easy, because if you think of the drawbridge, the pole is the pole that moves right. This is the pole and then the throw is the direction that it throws too.

How many how well, actually you know what i always get this backwards? No, that is right. Yes, it is. It is right. Yes, no seriously.

I've done this like six times, because there is an actual diagram out there, a really common one. If you look it up on google, that says it the wrong way, and it threw me into this like year-long spiral where i was saying it backwards. The pole is the pole, the part that moves and the throws are what they connect to. This is a single pole, because there's only one moving moving arm here right, it's only one switch in one and it's a single throw because it only connects and disconnects to one point on the other side.

What would happen if i made it so that it was? There was another one that it could connect to it's normally closed here now we have a single pole, double throw single pole dt and if we wanted to say the whole name of this guy right here, this would be a single pole. Double throw close on rise pressure switch too much no, but that is what it is, and you know all of that literally from just looking at this picture, which i think is kind of cool, it is cool yeah. You like it. That's kind of the point of air conditioning you know, make things cool sorry.

I was my bad, my bad, my bad all right, so that's it we're just gon na start there. Oh, oh, oh! No! No, we're not gon na stop there. I completely forgot. I forgot the most important thing: i forgot our most important component, so we've got loads, we've got switches, we've got power, supplies and conductors conductors, i'm going to add one more thing to the list.

Insulators. This isn't fair because it's actually not part of the electrical circuit, but it does serve a purpose right and we know that, let's start with conductors versus insulators. What's the difference, i want to insulate the wire one prevents electrons from moving through it or energy. Even more broadly, because we can talk in terms of conductors and insulators in terms of heat moving too right, we want to insulate our attic, so we prevent energy from moving through yes nicholas talking to our electrician, oh boy, never you tried to never do that.

Have you ever heard of it has to be pure water, pure water, being an insulator, oh yeah, okay! So what is that application for pure water? Nothing nothing it just is. It actually comes up in certain cases when you have, because there are certain type of electrode switches that are designed to trigger when, when water, when they touch water and the water and the electrons can move across if the water is too pure yeah. If the water is too pure, it won't actually make the circuit and i'm trying to remember exactly what application that becomes a problem, because it certainly ain't a problem when it comes to regular ac condensate. But there are cases where yes, pure water, it's actually the minerals.

The other stuff in the water, that is, the conductor, not the water itself, i mean water itself - is also a conductor, but it's just not a very good one. It is an insulator all right, so what's a load consumes. Power is a way that it is often said even in some textbooks, it really isn't consuming it. It's just changing it into work, but we can think of it that way it draws amperage.

It makes your power. It makes your uh meter spin on the wall. You have to pay for the wattage that a load uses as a way of saying it, but really a load is just taking that electrical energy and converting it to another type of energy. It's not using it so to so to speak.

But what are some common loads? Let's name some right above you just just name, it come on, come on light, bulb light bulbs, the load, what else air conditioner? Well an air conditioner is made up of a combination of loads and switches and all these things right. So we're talking about individual components fan motor. Yes, the motor all motors are a load. What else heat strips are a load when you plug something in it, isn't considered uh, so we'll we'll call it a load.

But again that's an oversimplification. Most things that you plug in are a combination of all of these things, because if you have, let's think of a vacuum cleaner well, if you didn't have a switch in the vacuum cleaner, you couldn't turn it on and off. If you didn't have wires you, wouldn't it wouldn't connect into the motors and everything else. You know the beater brush and all that stuff.

It's got loads, it's got loads, and so we would call it a load as a simplification, but pretty much every appliance is going to have all these in it. So what are examples of switches, light switch light? Switch contactor is partially switched partially load right. The part that opens and closes is the switch. The part that makes it open and close the magnet is a load.

So a light switch is truly a switch because it has no it. We physically have to turn it on and off a disconnect is only a switch because we physically have to push it in and out right. There is the same way: a breaker is a switch yeah. Now are there breakers that have um? You know logic in them.

There are, they have some of my microprocessors and actually do consume some energy or convert it to heat, but anything that creates lighten heaters designed to as a load switches are not designed to create light and heat or magnetism. They may, in some cases, if they have a poor connection to damian's point earlier, if you've got a poor connection, that is going to generate heat and it becomes sort of a load in an undesired way power supply. We all know what a power supply is right. In terms of our buildings, that goes all the way back to the power plant and that's what we call a almost unregulated power supply, meaning that we can put a lot of load on it and we'll melt the wires in our house before the power company is Going to stop providing us enough power right if we, if we took out our main breaker and check out all of our breakers and we hooked something live up to the main lines.

We would melt all the wires before it would stop providing us with the energy. But when you're hooking up to things like batteries or solar cells, anything like that. Well now that is a limited power supply. It's only going to give you so much at a time, and so that's another distinction.

Power supplies can be regulated or unregulated. A transformer is both a is both a load and a power supply. It's the power supply for our low voltage, control circuitry. It is a load on our high voltage, circuitry and then conductors and insulators, which we already talked about conductors are just paths.

They shouldn't consume energy, but they do right if i were to take a long run of wire and take a volt meter and measure across it from one point to the other. I would see a voltage and that voltage would be the voltage drop across that conductor and there will be - and you don't have a voltage drop unless there's a resistance so even conductors have resistance to them. Insulators are designed to have resistance, they're designed to slow the movement of current or make the path very difficult for current to move through. There's a lot more here like we're just scratching the surface, but in terms of terminologies.

That's what this is. This is just introducing you to some terminologies and some basic ideas of the electrical circuit. You.