So I'm about to go into video on duck detectors or smoke detectors. I just want to give you guys a little disclaimer some areas. Some people may consider these to be a life safety device kind of know. Your local codes know what your insurance covers with your company, make sure you're not getting involved in something that can get you into trouble.

Okay, I don't mess with alarm panels. Ever I don't ever cut alarm wires. You know, that's just me. I'm allowed to change doc.

Detectors, though, okay so be cautious about what you guys get involved with, and here's the video all right. So today we are gon na be talking about. Duct smoke detectors. Okay, we see these in our industry.

We can see them in ductwork. We can see them in our tu units, mainly we're gon na be simplifying the wiring on them. Okay, they can be a little bit intimidating and I'm gon na try to break that down for you guys and show you what's going on. Okay, so, first off, let me explain that we have a simple 24 volt transformer running.

Both are running this duct detector. Okay, you look up here. Here's my 24 volts. Okay, the way that I have this set up.

I set up this little trainer just to show people at my office how to work on these things. Okay, so these are our sensor heads okay, they are actually what senses smoke. They have two holes, one right here, one right here going through the detector and they typically have a large tube with holes drilled in it. They call those sampling tubes.

The theory is, is that you put them in a pressurized. Duct and air will be forced in one area through the detector head out the other area. Okay, this detector head is simply there to do one thing, and that is to look for smoke when it sees smoke. It sends a signal to your circuit board or your electrical module, whatever you want to call it, and that is going to have a bunch of different relays in it, and we can do all kinds of stuff with it within this guy.

You can, you know, go through the instruction manual, which I have right here and it'll. Tell you all the different things you can add to that. You can add annunciators, which will be audible, alarm devices. You can tie it into the fire alarm panel.

You can tie it into your rtu unit or your air conditioning unit to shut things down to turn things on. You know. Basically, you just have a bunch of relays in there in the skies kind of the limit on what you want to do. This is a newer model that has a electrical module with two heads before in the past.

We would have to do two separate duct detectors and tie them together, but they do make these now to where you can do to detect your heads with one module, and that is pretty cool. You tend to see that in a lot of factory-installed rtu units. Lately, okay, so let's break down this wiring inside here. This is one of the easier ones to work on because they label everything for you.

Okay, so it makes it easy. Auxiliary contacts are typically ones for us to hook up to our rtu unit. So we have two auxiliary contacts for us to do what we wish. Okay, then we have a supervisory contact and then we have an alarm contact.

Those two are typically going to be tied into the alarm system and I'm going to try to break that down and show you guys why and what they're doing with that. First off: let's look at the simple fact that we have an auxiliary contact right here. I've got three wires going to it mind you guys this is 24 volts and it is energized. Okay, I'm not gon na hurt myself on this.

I don't want anybody to think that I'm sticking my hands in a high voltage situation and for the people that are gon na, send me the comments I do realize that 24 volts can even hurt you we're gon na look at this auxiliary contact. What I'm doing with this auxiliary contact? What I could potentially be doing is shutting down my air conditioning unit, my fan, whatever I need to shut down when there's a fire condition. Okay, you notice that we have one common terminal, one normally open terminal, one normally closed terminal, so depending on which, let's just talk about an RT. U unit, depending on which manufacturer on a train unit.

I was working on one the other day and they wanted to break a 24 volt wire going to the emergency, stop so for the unit to work properly. They need to have 24 volts going to the emergency stop terminal. So with that being said, I would wire the R leg from the transformer of that r2 unit to common, and then we would basically wire out of the number 20 terminal on the detector. The normally closed to our emergency stop and it would be normally closed in normal operation when it's not sensing smoke and it would open.

I happen to know that on a Lennox unit, the Lennox prata, the Lennox l-series package units that have the prodigy board they're. Looking to send or to make a circuit to put the unit into emergency, stop okay, so on a Linux unit I would go from common or from R to common and then out of normally open. I would go to their smoke detector terminal and if the smoke detector tripped, we would close this circuit. Okay, then we would send 24 volts to the smoke detector terminal in the AC and the AC would do an emergency stop and shut down immediately.

So, but you really could do quite a bit of anything with that, those those auxiliary contacts. You could you know it's a set of contacts. Okay, now I will say that these contacts on any of these auxiliary relays, even the Supervisory, even the alarm contact - are not powered by anything okay, so you have to power those contacts. So there's nothing in the detector powering the comment on those contacts.

Okay, so you do all the work you come in with 24 volts and do what you want to do with it. Now, let's talk about our alarm contact. Okay, most modern alarm panels in a restaurant are going to be looking for two things: okay, but they're going to use two wires to do it all. They are looking for a direct short between red and white to indicate that there is a fire condition or a smoke condition, but at the same time, they're always looking to see a resistor across those two wires.

Okay, so let me break that down the alarm company is monitoring two wires. That's it! Okay, I'm gon na step up here to my little terminal block and I'm gon na show you that these red and white wires right here. This is, let's just imagine, that's our alarm panel. Okay, our alarm panel is looking to see two conditions across those two wires.

Okay, they either want to see a direct short which is going to indicate a fire condition, or they want to see a resistance value of which this resistor right here gives us to prove that our circuit is intact. Okay, let me ask you something: what happens? How does the alarm company know if a mouse has gone up into the attic and chewed? Let's step up here any one of these wires, these two wires, this white or this red? Okay, if something happens, and one of those wires gets cut, then there's a fire condition. How is the alarm company going to know that there is a fire condition? We need a way to prove that that circuit is intact. We need a way to say that there is nothing wrong with those wires and we know that if there's an alarm condition, we are going to get a direct short across those wires.

So what we do is, we add a resistor into the circuit. Okay, that's this! Guy right here, for all intents and purposes, I'm using a 15 K, ohm resistor, okay, but I will say that each alarm panel is individual and you know they take different sized resistors. So we as technicians in the air-conditioning industry, are not going to be messing with the alarm panel. That is the responsibility of the alarm company, but it's good to know what they're looking for.

I just like to know exactly what's going on so the alarm company is looking to see that that resistor is in the circuit to prove that our circuit is good so that we know we don't have any broken wires. Okay, when there is not an alarm condition. The alarm panel is looking and it sees our 15 K ohms, okay, so I'm jumped across the red and the white, and you see that I see 15 K ohms. So I have proved to myself that my circuit is good.

There's nothing wrong with my wiring circuit for my alarm panel, okay! So now I know that if there's ever an alarm condition, I'm gon na get the direct short across these two wires. That's gon na tell me that there's a fire condition. Okay, I'm gon na simulate an alarm condition right now: okay, there's a couple different ways: you can do this. I'm gon na use a magnet right on this terminal of this detector right now, I'll sniff.

I can get this to click okay, so I just clicked it you notice. I get the red lights on my detector, so my detector now is in an alarm condition. It thinks that there's a fire or it thinks that there's smoke and it's sending a signal to the alarm company, okay of which we are gon na, hear in our tone, direct short across the red and the white wires. Okay, I now have a direct short across my red and my white wires and the resistor is out of the picture now because we have a direct short okay.

So if I was to reset my alarm system now, I'm gon na go ahead and use my test and reset station. Okay. Now I go back to seeing just a normal resistance value. Okay, so the alarm panel is, you know, constantly looking for that resistance value and what we you know.

We just want to prove that that circuit is good. Like I said okay, so I'm gon na go ahead and go back across and we are gon na get our 15k ohms all right, pretty simple detectors can be a little. You know intimidating because there can be a lot of wires in here like what do all these wires do. Okay, but just systematically break them down.

You know it's a simple it. The way that I do it is looking at the thermostat wires. Okay, you'll tend to see you know three to five thermostat jackets coming into there. This is a jacket right here.

Okay, so break them down that way, because, typically, each jacket is going to be one function. Typically, okay, not always, but here I have an alarm wire. Coming in you know on the red and the white and then you can kind of look at the schematic okay, so I have wires going into this contact right here. So that's gon na be one thing that happens to be my rtu unit.

Then I have my main power up at the top, those two wires in the corner, and then I have my test in my reset station, which I haven't really talked to you about, but you saw me use and that's this guy right here. Okay, you'll see these typically located down in the office area. This is a we call it a test and reset station, and that's simply there so that way, if there's a fire condition or the alarm gets triggered, we can reset it remotely down inside the occupants ID the building or we can test the alarm from down inside The building a lot of times when, when restaurants are there, they'll, have an annual inspection from the fire marshal and he'll come through and test all the def detectors. If he's doing his job right I'll tell you that most of the time they don't no joke.

I've found restaurants that have had duck detectors installed in them for six years that I've found to be Mis, wired and there's no way they could have ever worked properly. So obviously they hadn't been tested very well. So I can trigger an alarm from the remote test station. Sometimes they might have a uncie ater that screams out you.

They might have a green light, indicating everything's, okay, all kinds of different functions. Okay, you just need to read the instructions. This particular one has a test, so you just apply a magnet to it and then you can reset it by holding down the button and it goes back into normal operation. Some of the anunciar, some of the test reset stations have a key.

You know everything could be different, there's also different brands of duck detectors. Okay, this is, in my opinion, one of the more popular ones right now this is system sensor. You see this in a lot of equipment, but you know there's different brands. There's older brands that don't exist anymore, you can run across a lot of stuff.

Ok. The next thing I want to talk about is my supervisory relay: okay, su P, or in some detectors it might be called a trouble relay or a trouble contact. Okay, what that's there to do in this particular detector? The Supervisory contact is there to alert us if there's a problem with the duck detector head, I have the ability of setting up this detector to alert me if someone tries to mess with this detector head. It's called a tamper sensor.

Ok, so what I'm gon na do is I'm going to tamper with it. I only have one screw holding the cover on right now, but there's actually a micro switch in here and if you take this cover off we're gon na send this detector into it. A trouble condition notice. We got an amber or an orange LED, and what actually happened is now my resistor has dropped out of the circuit.

So if I go up here to my red and my white wires, I will no longer see my 15 K ohm resistor, but I'm not in a direct shorted condition. So the alarm company knows that something is wrong, but they're not seeing a fire condition. Okay, depending on how the restaurant or the building has set things up with the alarm company, the alarm company may dispatch. You know PD.

When you go into a trouble condition, they may dispatch the fire department they make, may make a phone call before they dispatch anything. It all depends on what they have set up. I have this set up with a tamper. I call it a tamper circuit, okay.

So the way that I have the resistor wired into the circuit is it's running through the supervisory contacts. With that being said, if I power down this rtu unit, the alarm company is going to know that I have powered it down. They are not gon na get an alarm signal or a fire condition, but they are going to get a trouble condition. Okay, my 15 K, ohm resistor, is gon na disappear from the circuit.

If I power down this rtu unit, okay - and I will prove that to you guys, right now by turning off the power, so I've turned off the power to my circuit now, okay and we'll check it up here. My 24 volts is my red, and I mean my yellow and blue. We no longer have 24 volts and you notice that we no longer have any green lights in the duct detector flashing at us. Okay, what I'm gon na do is I'm going to put my meter into ohms and we are gon na test resistance across the red and the white wire and you notice we get nothing, but we do not have a direct short a lot of Arts.

U units at restaurants are set up this way with. That being said, you always always always want to let the fire alarm company know you are gon na be working on an RTO unit. If any of you has run into this problem, like I have, I was working out a shopping mall. I went up and started working on an r2 unit.

25 minutes later the fire department showed up. I did not put it into an alarm condition. I did not do anything wrong. The only thing I did was I did not notify security that I was going to be working on an r2 unit, it's very important, especially in shopping malls, but even in restaurants.

I have some restaurants that what will happen at the restaurant you know is: if you do not notify the alarm company that you're going to be working on the r2 unit, they will get a trouble condition and they will call the restaurant if the restaurant doesn't pick Up the phone within a certain number of rings, they will dispatch the fire department how'd it happen at a restaurant. So it's always important to know your restaurants and know how they work. Ask management you know: do we need to put the fire alarm in to test? You know cover your, but if they choose not to put it in to test, but you asked them to then hey your butt's covered. You know you're not going to get in trouble.

All right so we've talked about the auxilary context. We've talked about the supervisory contact and we've talked about the alarm content. Okay, if you want, you know on this supervisory contact, I'm gon na go back and tell you something that you have to read in the instructions. Again, I have my instructions right here, but if you read in your your duck, detector duck detectors instructions.

You will see typically, that there's some goofy stuff going on with the trouble contact or the supervisory contact, for whatever reason I don't know why. Maybe someone can tell me why they do this what's listed on? This contact is backwards, okay and the reason why Lisa's as far as the instructions go with the Supervisory contact, the normally open circuit is normally open when it's in a trouble condition and the normally closed circuit is normally closed. When it's in a trouble condition. I am NOT in a trouble condition right now.

I am in normal operation. All these other contacts operate normal, so my normally open is normally open right now, when I'm energized same thing on this one same thing on this one: the alarm contact, but the Supervisory or the trouble contact they're reversed. So if you're ever trying to wire one of these up - and you don't know what you're doing you could get confused because it'll be reversed. Basically, so if I test it between common and normally open right now it's closed and if I test between common and normally closed, it's open, unless I put it into a trouble condition: okay, and we can prove that right now, so we're gon na go.

We are not in a trouble condition, we are in a normal operating, you know, energized condition, normally open and common is going to be closed, and here we go so I can get my meter in there see. We are closed right now, but we are not in a trouble condition. I am on normally open in common same thing. If I go to normally closed in common, it is going to be open.

Okay. So, for whatever reason, maybe it's just to confuse me and irritate me: they do that on this okay, so we have an open circuit, but it says normally closed. If I put this into a trouble condition, all the sudden, those contacts will work. Okay.

So that's something to know on these dock detectors now, when you're working on duck detectors, they're, obviously not going to be on a board like I've made them like this they're going to be in an RT. U unit, you're gon na typically have one in the return. Duct work one in the supply duct work. It may not be as nice as my setup here where I have one module unless you're working on a newer packaged unit.

You might not see this setup. Okay, it's still the same principle, though. If you follow the manufacturer's instructions again right in here, if I had two individual duck detectors, I could wire them up and they have communication between the two detectors. You have the ability to wire in a few detectors together and you'd, basically just daisy chain the little communication port and then they all talk to each other, and you know you can set up all kinds of different things.

If you look on this detector right here, I can, you know, change the way that the trouble shutdown happens. I can add one or two sensors to this one electrical head, which I have right now I have two sensors and then I can also change that tamper delay. So I showed you guys that one I can change it to a seven minute delay. So when I took this head off there, this cover off and immediately went into a tamper mode, and it's sent a trouble signal to the alarm company.

If I flip that dip switch, I can make that wait. Seven minutes before it sends a trouble condition so something to think about. Read your instructions. Okay, let me know if you guys have any questions.

This is just a simple little duck detector setup I have going on here. These things have always confused me, and you know, after working with the alarm company multiple times, I finally decided to figure them out, and you know then I'll be honest with you. The one thing that really got threw me off was this supervisory contact, because it would just, I would always be confused until I finally opened up the instructions and read it and realized. Oh duh, simple, okay.

Another thing on these detectors right here you do sometimes have to they'll, have sometimes filters on the sampling tubes going through. There is maintenance that needs to be done to these detector heads. You can twist them off and you know clean filters on them different things. So something to think about these are not great in moist ambience, you know they do make NEMA for duck detectors that have a little more water resistance, even the NEMA four ones, though they tend to have a lot of problems in really high humid areas.

It does matter where you install the sampling tubes. I've had sampling tubes fill up with water because of humid conditions, so always want to read the instructions on where to locate them and how to locate them. So hopefully that answers a few questions for you guys. You know duck detectors, used to be very confusing to me.

I've kind of simplified on they kind of make sense to me now. You know I could keep talking on and on there's all kinds of different things you can do with them. So hit me up in the comments guys send me an email. Let me know if you have any questions, you know pay attention at the end of the video right now.

Popping up is some other channels that I recommend great content on those channels and that's pretty much it guys. Okay, so we'll see you guys on the next one.