Alright, so in this video I want to show you the 9340 relay and go over some simple steps of how to use a 9340, what the different parts are of it and what some of the ratings are on the actual relay itself. That's a first off this is a typical 9340 relay box, they're made by multiple different brands. The nine is cut off here, but it's 93 for a year. This stands for double pole, double throw, and so the throw is the part of the relay that actually moves, and the pole is the part that it connects to so a double pole.

Double throw relay is going to be a normally open and normally closed, relay unique and it can be either. I can add both normally closed contacts and normally open contacts. Let's go ahead and open the box alright. So this is a typical 9340.

When you look at the top, the first thing that I want you to notice is that you can. It has a little diagram printed right on the top of the 9340. That's one of the things I really like about it. A lot of relays do have a diagram printed on, but the 9340 is nice because it's actually in proximity to the actual terminals.

So that means that this is terminal 3. This is terminal 2 terminal, 1, 4, 5 & 6, and then these are the two coil terminals. So that's how you can identify the actual terminals and it actually shows the connection points. So you can see that one is connected to 3 through a set of normally open.

Contacts. 1 is connected to 2 through a set of normally closed contacts. So, if you're, not really, if you have don't really have a lot of experience reading diagrams, you can trust me this little symbol here, the two, the two lines with the slash through it. That's normally closed that little symbol.

There right here is normally open contacts. Let's take a quick look at the coil itself, so this is a this is an electromagnet electromagnetic coil and the coil has a rating. If you look on this data tag here, you can see it says: coil 24, volt, 50 or 60 Hertz, which means that the rated coil is rated for 50 or 60 Hertz. So it could be used in the US or other countries that use 50 Hertz.

And it's rated for 24 volts, which means that when you apply 24 volts between these two terminals, so when you have a potential difference of 24 volts, these two points: this creates an electromagnetic force that switches the relay okay. So you can tell that this is the coil, even though, if you look at the diagram on the top here on the 9340, the coil isn't mark. There's nothing, there's nothing on here. That shows that this is the coil, but you can tell it's the coil really easily.

Just by looking here. You can see this little wire how it's connected from this terminal down and then it goes down around and actually connects to this coil underneath. So this coil creates an electromagnetic force that then switches. The relay contacts for the relay will call the contacts.

Sometimes some people call them contacts. Some people call them the switch. Some people call them points, so you would say between 1 & 3, so between 1 & 3 is a normally open contacts set of points or normally open switch. Any of those terms are kind of used in the trade, but technically speaking, they call them contacts within a relay, and so what switches this relays? It's a remote switch.

What switches it on and off is whether or not we have 24 volts applied to the actual coil of the relay itself. So if you look at this data tag here, you'll see the coil is rated to 24 volts, but then we have contact ratings and this is the ampacity how much amperage? What is the amp capacity of this relay and so at 120 volts. It can have 80 2.8 locked rotor amps. That's that sort of instantaneous power that a motor uses when it first starts up or when it's locked and then 13.8 full load amps at 124, T volts that drops down to 6.9 full load, amps and 39.6 lock rotor amps, and then it just keeps going.

You'll see so these are for motor loads or inductive loads. These are magnetic loads generally motors. So if you're controlling a motor with it, you have to follow these rules based on the voltage. But if you're controlling a heater, that's a resistive load, so there would be like a heat strip or a incandescent light bulb, and you can see at 150 at 120 volts.

It can control 15 amps 15 amps can be run through it. That's the amp capacity and 15 amps the same at 277 and then it drops down to ten if you go up to 480 volts. So that's the ampacity of the actual contacts or the contact rating, how much amperage? How many electrons can go through these contacts without the relay, failing because of melting or or the actual electrons bridging the contact points in the case of high-voltage, which is why you see that main pass? If you go down the higher the voltage goes. That's one of the reasons so a quick demonstration of how this works, I'm going to go ahead and put my meter on the own scale.

So it's going to read in ohms, but really we're not reading ohms we're reading continuity, which is essentially just a pass/fail path or no path. So you see here how it rings out at shrink continuity, so showing a path between these two probes. So when I go from here to here, these are normally closed contacts. So there's a path.

Now, if I were to switch the relay meaning, I were to energize it with power here, then it would switch and there would be no path between here and here and now there would be a path between here and here. So you see right now between 1 and 3, with no path between 1 and 2 there's a path because the relay is closed. Alright, right now, there's a path between these two there's, no path between these two. So now let's go ahead and switch the relay.

I'm going to go ahead and connect it to power what I've got here. I've got a little 40v, a transformer connected to 120 volts with a plug right here. So I'm going to go ahead and plug this in and then I can control this with a switch. Just a little just a little blade switch that I'm going to set right here we're going to go to our relay coil out of the other side of the relay coil, and this is where a lot of guys get confused, because this is not a switch.

This is a load. This bottom part here is actually taking electrical energy and it's converting it into electromagnetism. That's switching the contacts so where, as contacts are just making and breaking switches making and breaking points up here, the actual relay coil needs to have 24 volts of potential applied across it. So, in order to do that, I'm going to take the other side of the transformer, the other side of the transformer secondary here, and I'm going to connect that here so now what's happening.

Is we have our hot leg coming out of our transformer? That's going into the switch and then out of this switch it's going into our relay coil and then back to the common side, the other side of the transformer. So we get our plug here. We're going to plug it in switch is open right now. So when I energize the switch, the relay should switch here.

The relay switching! That's because we're applying power, I red wire, is power coming from the transformer. So my red wire comes here goes around into the switch and then out to one side of the relay. So when I close this we're applying unfor volts of potential to coil, so this is our coil. If you look here so it switch is open right now, if you look here, this is our coil.

You can see the little wires connecting down that connect down to the base. So when I apply 24 volts to it, it closes the relight. So let's go ahead and put this so you can see right now. The circuit is open.

That's why it says open here on the screen: I'm go ahead and put this on the normally open switch here, normally open contact points, and I'm going to close this clips. So now the circuit that open is now closed, pull this up here, so you can see it a little better. Now my alligator clips connected to one and three right now we're open, because the coil is not energized as soon as I energize the coil. It makes the circuit the opposite is true.

If I go between one and two, it's normally closed. So when I don't have 24 volts of potential applied across the coil, then it has made a circuit. So there is a connection and then, as soon as I energize it, it breaks the connection, so it was normally closed and it goes open when I power the coil 24 volts, don't let Spacek aliyah, that's how it works. Same thing is true of this lower set.

Normally closed open, go ahead and connect between 4 & 6. It's normally open. It goes closed. So you can see here.

This is how this is connected. Good, this connector things you can see it again. So that's! Basically it go to unplug power. We've got a 9340 relay depending on whether or not you apply 24 volts of potential across the coil.

It switches the state of the contacts from normally closed to open when it's energized and from normally open to closed when it's energized used for a lot of different. A lot of different applications and you have to make sure to pay attention to both the coil rating in voltage and then the contact ratings and ampacity. Based on whether or not it is a motor load, otherwise known as an inductive load, which just means magnetic or whether it's a resistive load, which is generally things that create light and heat there, you have it, i'm brian, with hvac school, we'll see you next time.