This video is brought to you by sportlin quality, integrity and tradition, we're here today, because the fire alarm company said that they have a bad duck detector, but i'm intrigued because, as i'm walking around the roof, i'm looking at this and look at the roofers. They sealed the exhaust fan. Why? I don't know they uh sealed the top of every ac. Why i don't know so? For those that don't know the water leak is not at the top of the ac.

The water leak is not at the top of this ac and the water leak is not from this exhaust fan. Good gosh man, i guess the roofing guys are having a hard time just like we are finding people look. The water leak is not at the top of the electrical disconnect. That's not going to do anything good grief, some people's kids right, my goodness, gracious, that's nuts anyway, so we're here to change a smoke detector.

Now i'm a little frustrated - and this is happening kind of this - is how it is all that they say i have no documentation. They just said the fire alarm company said to change the duck smoke detector for rtu 3., so i already told them to call the fire alarm company and put the system on test, which is what you have to do on this particular setup. The smoke detectors should be in here, sometimes there's one, sometimes there's two, so there's not one in here. More than likely it's just going to be in here all right there it is.

I have no idea what's wrong with it, i'm i'm very reluctant. I don't like changing things without this is off. I don't like changing smoke detectors without talking to the people that diagnosed it, but i'm going to open this guy up and we may just have to replace it and then have them come to a meet-up or something like that because yeah they have weird signaling devices. On these things - and i don't know what they're doing with those but all right - well, let's just open it up and see what it looks like now.

This is a very old um invincis smoke detector. If i remember right, i don't know they're kind of all the same companies anymore, i think, but uh this was the filter. You can see the filter completely disintegrated. So that's a big problem.

Oftentimes on these older ones. What happens? Is the they're just dirty in the sampling, tubes and stuff, but you don't really risk it on these and whenever you are having problems, you typically replace them. So as far as the alarm wiring, i usually like to have an alarm tech here but looks like this. Is our resistor for the fire alarm panel? Doesn't look too complicated if you look right here, this is the uh like schematic or whatever, we'll have to bring a vacuum in here, because i don't know what this stuff is, and i really don't want to be breathing.

This, but right on here is going to be a schematic explaining you know what happens or a legend or whatever all right. Now i stock smoke detectors in my van typically have one it's not going to be identical. It's going to be a different one. Actually, i think this might be the same brand, just a newer version.

I think, but anyways um, i'm vacuuming out this section here - real quick, not going to go too crazy, but i want to get a little bit of something out of there right. The unit's trashed blower assembly is caked with gunk and stuff. That's a whole nother problem for another day, i'll bring that up to them, but i just want to get my work area cleaned up a bit, so it's not as nasty, so i already got some of it now i just got to get the corners and you Know this area in here this one had a standoff bracket and the standoff bracket's actually not correct, because it doesn't really allow for enough uh penetration of this tube right here for the exhaust port um. So we're going to move the standoff rack bracket and it's actually gon na work out perfect i'll have to elongate those holes which i have a special hole saw for that it looks like we'll be able to line right up to that screw right there, and then This side, we'll have to look and see we'll have to figure out how to make it work with this, and it may work out that it doesn't sit flush anyway.

So we'll see we'll move it around. We may move some screws but looks somewhat decent, so we're gon na get this guy mounted um. I do not have the sampling tube with me. I'm gon na have to measure the right length and go get one, which is fine, but i want to get this guy installed and wired in so i keep a giant hole, saw or unibit step bit whatever you want to call it, and this is perfect for This it only needs to be elongated a little bit, so i took care of that and this is going to work out perfect where we're going to put that screw right through and then this one will be able to sit behind, because this doesn't sit completely flush.

Anyways, so it's going to work out perfect, we'll get this guy put in then we'll start on the wiring process. All right! Looking at this guy right here, this guy, this replacement one - can be 24 volts or 120. uh. This one was a 24 volt, so we'll use that and it looks like the power inputs are going to be the same 9 and 10 is 24 volts and then let's just pick a few more 19 and 20 are in auxiliary in and out yep.

So 20 is a negative yep, that's it so it's it's! This is the replacement for this one right here, so you still want to make sense of the wiring, but it really it's going to be wire for wire on this one now. Another thing to understand, too: this is a outdoor one. This is supposed to be waterproof, um notice, it has solid cover, so you can't see the indication stuff, but that's fine. It's not a big deal.

This one also has the ability of having a second detector with one control assembly and, at the end of this repair, i'll pull up an explanation using my trainer board using this type of smoke detector, and you can see how you can actually have two heads right Here i can mount a head here and a head in the return and then just have one control assembly and sometimes we'll even take this control assembly and put it over in the electrical section and just have the heads over here and you can see you can Have up to two of them on this setup right here and you just wire them into here. I really dig this detector. It's super nice tamper, sensors right here, so i'm gon na get started with changing this over. It should be a wire for wire, but i'm still going to do a wire one wire at a time to make sure that everything goes across properly.

When doing these detectors, you always want to put the fire alarm on test. Notify management that there's potential that the fire alarm can go off, make sure they know how to reset the fire alarm and or silence. It always be cautious. Okay, then, what i do is i do it one set of wires at a time and what i mean by that is typically there's a set of wires.

That's going to interface into the unit. That's this one. Okay, it's actually hardwired into the unit. This unit came with smoke, detector inputs, okay, so on this one you've got 24 volt power that powers the detector, a common and a hot leg right for the 24 volt power.

Then you have a jumper wire going to a common of a contact, and then you have a normally open contact that comes out. So what they're doing here is they're, jumping 24 volt power to the common and then, if the duct detector trips it closes this circuit and sends power on this orange wire to the 24 volt smoke detector input. That would then do an emergency stop on the unit. So i do it one set of wires at a time.

So this is the ac interface. Then we're gon na have a test and reset station interface, so you can remotely test and reset it from in the manager's office and then you're gon na have a fire alarm input. So i do it one set at a time that way. It's not too confusing makes everything make more sense all right.

This guy just turned on now. I did not wire in the alarm wiring yet, because what i'm going to do is we're going to test the duct detector's functions and operations before we tie in the alarm to try to prevent a fire alarm from going off. So i will land the wires as they sit on that detector on the new one and then what i will do is. I will have the restaurant call.

The fire alarm company schedule a meet-up with me that way they can come out and test the operation of their system to make sure that there's nothing wrong, because i can't be liable for their system not working right, so they currently from my understanding, have this zone. In a test, meaning that they're not monitoring this zone, but i still treat it like they are and i'm going to schedule to have them come out, but we are in normal operations, so i should be able to trigger this guy hold it down, smoke, detector, tripped And the unit just shut down in a fire alarm condition. So if we come over here, we should be able to open this up and we have a number four on the display, which means - and i believe, if you come over here, i can't remember what the smoke detector input is. Oh, they have it done hardwired in here, but number four is a depth.

Detector come right here, indicate smoke alarm, so this is correct. This is how it's supposed to operate now. What i need to do is head downstairs and find out which, which test and reset station is illuminated, because i'm going to replace that. Also whenever i change the duct detectors, i always put in a new test and reset station.

So this is a one that does not have a key. This one works off of a magnet and a push button reset. So we'll replace that, but we're using this to tell us which test and reset station this works with, because it should be illuminated right now and then we'll replace that and then, like i said well, then we'll tie in the fire alarm. We can see that this is the test and reset station in concern.

The other ones are not lit up um, so we're gon na go ahead and replace this guy and then we'll test it again after that to make sure that it works and we can test and reset it from the test and reset station all right. We should, if i did everything right, be able to trigger it with this, see should trigger it, but it's not so we'll have to go up there. We go so now. The fire alarm should be going off right, but it's not, and then we reset it by pushing that button.

Okay, so we know that it tests and resets from up here, so we can trigger it again. I always leave the magnet up here for the fire inspector. If he ever comes right, they may lose it, but at least i left it and then you hit reset. Oh there we go so test and reset's done um, maybe i'll even take that magnet and set it up on the fire alarm panel.

That way, nobody's gon na be working up there, so this is three we'll go ahead and mark that guy as rtu3 and then we'll finish up on the roof. Okay, so i left it, i put it back in an alarm condition. So that way, i could verify that it was actually alarmed up here, so we reset it. Blower should start back up here in a second.

So that's good! Now i'm gon na go ahead and there goes the blower. So we know that the emergency shutdown and operation is working. Now, i'm gon na go ahead and transfer over the alarm wires. They're, only monitoring, they're not doing a trouble circuit on this one, so they're only monitoring an alarm condition with a resistor, so we'll go ahead and transfer that over carefully and then we will go get our sampling tubes.

It's not perfect, but i did my best to clean up the wires because when the drains overflow, sometimes this can fill up with water. As you can see the rust so by cleaning that up, you know, keeps the wires off the ground, zip tied everything up nice and secure, so we're good in here again, i'm gon na go get my sampling tubes, then come back as you're pushing in the sampling Tube, it does have an arrow onto it. You wan na make sure it's pointing into the air stream. So, in this case, the air is forced down into this and because we put a plug in the end of it, it can't go anywhere but out this port through the detector head and then back in through the exhaust port.

So you got to make sure you get those in correctly that one should face in that direction, just like that and then we'll push the exhaust port in there all right. I've got my duct detector trainer board here that i made i made this a long time ago. I've shown it in several videos, but it's a great little tool to help explain how duct detectors work. Okay, so the primary purpose of a duct smoke detector is simply to be mounted in the ductwork.

You have sampling tubes and exhaust tubes going into the ductwork. I showed that in my video, but on the back of this there's two holes coming out. Okay and one of them is going to get an exhaust sampling tube that the air is going to be forced into the holes and then it has to be come through. The detector head and then exhaust back out into the air stream, this particular setup has one control module and two sensors okay.

This is just like a duck smoked or duct. Uh smoke detector at your house, essentially, okay, but it's meant to be mounted in the ductwork and have air forced through it. Now a couple different features: this smoke detector control assembly right here is 24 volt powered okay. So if we go right into here, we can go here and here and we should get and there we go 26 volts now, i'm kind of making contact and not making contact.

So it's a little funky there. Let's try that again. There we go so now we have 26 volts coming into the detector, always pay attention to the type of detector you have. Sometimes they can be 120 volts too.

Now this one has the markings for 120 volts, but it doesn't have any contact points um. This one's actually not set up okay, but sometimes they can receive either 120 or 24 volts all right, so very important smoke detector is there to sense smoke. We force air through now. Let me ask you something: what happens if one of these covers is off and how would it sense smoke if the cover was off? Well, it wouldn't right, because you wouldn't have the ability to force the air through the detector head.

If you did that, and if we set it up like that, now that air is, if it's forced into the sampling tube, it's not forced to go through okay, and if you notice, we have an orange light because we have a trouble sensor or a tamper sensor. Right here, okay, if we short those two, then that light will go away or if we simply take this cover and put it on there. It'll depress the little plungers and make the unit go back into normal operation. Okay, so i'm gon na go ahead and put this guy on, so it's important also that you understand, before you start messing with any duct detectors that you're a hundred percent sure that the fire alarm is on test.

Okay, you never know how the fire alarm. Company has the duct detector set up right, so you always put the system on test that way. If there is an alarm condition or a trouble condition, it theoretically should not call the fire department. Okay, theoretically, be cautious about that.

Now, as an hvacr service technician, my responsibility stops at the duck smoke detector. The alarm company brings their control. Wiring in here lands their resistor on the alarm contacts, and i have no control over those okay. I will occasionally install them, like i did earlier in this video if i'm replacing a duct detector, but then i will always get the alarm company to come back out after i'm done and verify that everything was done correctly and their system is back in line now.

The point i was making with the sample or with the head right here: okay, if the cover falls off, they want to know the alarm company wants to know. So when i did that i actually triggered a trouble condition. So let's do it again! Well, first, i'm going to show you i'm going to put my meter on or on ohms, okay, and what we're going to do is we're going to test. Let's see right here, red and white.

This is my alarm right here: okay and i'm looking at the alarm wires, the alarm company typically monitors two wires coming into the detector. Okay. In this situation, i have a supervisory contact wired in and notice that i'm seeing 15 just about 15k ohms of resistance. Okay, the alarm company has a end of line resistor right there and that end of line resistor is there to tell us that the circuit is intact and nothing is going wrong with the system think about it.

This could be considered a life safety device. What happens if this had a broken wire? These wires right here, there's red in this white? What happens if a mouse ate through one of those wires? Well, the alarm company? If they didn't have an end of line resistor on there, they theoretically would not know and being a life safety device. It couldn't prevent or signal the fire alarm company if it need be okay, if something was to happen, so we have that resistor wired in on a supervisory contact. Okay, so i showed you guys that right here, just picture this being the alarm panel, the alarm panel, seeing 15k ohms of resistance.

Okay. Now, let's show you right now. If i go ahead and remove this cover, we're going to get that amber, led again and we're going to go into what we call a trouble condition. Okay, there we go, the amber, led came across now when we go into a trouble condition.

We are no longer going to see that resistor in the circuit. Okay, look at that 15k ohms! It's not there anymore, because the way that we have it set up and configured in a trouble condition. The alarm company no longer sees the resistor, but they do not see a direct short. The alarm company is looking for two things on these two wires: either a direct short or either that 15k ohm resistor.

Or let me preface that with saying whatever resistance value that the alarm panel needs. It's not always 15k ohms, sometimes it's 2k ohms or whatever the alarm panel needs. Okay, so they're looking to see that resistor or they're looking to see a direct short and if they see a direct short, they know there's a fire condition potentially and if the resistor disappears, then they know that there's a trouble condition or something is going on, whether It be a broken wire, whether it be a cover, fell off or a bad detector head okay, so we have it wired up in a supervisory circuit. Now, even if we didn't have the supervisory circuit on the system that we were working on today, it did not have the supervisory wired up.

They still had a resistor across the two alarm wires, so it still was being used as an end of line resistor to prove that you had a good circuit from the red wire. You know colors are irrelevant, but in this situation from the red wire at the panel, all the way down that could be, you know hundreds of feet to the detector. Then it comes back on whatever color and this one white all the way back to the alarm panel, so they're looking for that resistor at the end of the line to prove that the circuit's intact. That way they know hey.

If there was a fire, we would be alerted okay, um or there. They know that if the resistor disappears, hey there's something going on. We don't necessarily need to send the fire department, but maybe we need to send a technician out there to figure out why the end of line resistor is no longer visible. Okay.

Now the next thing that the alarm company is looking for is a direct short okay. Now i just put my meter on tone and what we're going to do is across those same wires. Okay notice, we have nothing, no tone, no direct short, okay, we're going to put the unit into fire mode, so we're going to hold down this button, we're doing a test and notice that the test and reset station also lit up now. If we run across these two guys right here, the alarm company is going to see a direct short and their fire alarm panel is going to notify the fire department that there's something wrong.

Okay, doesn't necessarily mean there's a fire, it could just be smoke in the ducts because of a motor burnt up, who knows, but it should power down the air conditioner. So if we go from common to normally open it's closed and if we go from common to normally closed, it's open okay. Now, if we reset the alarm condition, we can reset it at the test and reset station which would be down in the office boom. All the sudden, these contacts are going to be reversed.

Common to normally closed has a direct short like it should and common to normally open does not so what we're doing right there. Let's step back, i told you that the supervisory contact is reversed. All the other contacts are normal, acting okay. So that's why, in a normal condition, normally closed in common is going to have continuity and common and normally open is not okay, so it's only going to be backwards on the supervisory contact now um again we set off the alarm.

We sent the signal to the fire alarm panel. At the same time, we want this duct smoke detector to stop my air conditioner from running or my motor or whatever. This is tied into okay. So we can then send a signal via this aux contact or this aux contact.

Anyone you want now, depending on the manufacturer of the air conditioner. It depends on how you have it set up. You could break a thermostat. You can send a signal to a emergency.

Stop feature you could break a signal. It just depends on each manufacturer how you wire up their air conditioner. Okay train wants their air conditioners to break a circuit, okay carrier um. I believe they want to break a circuit linux.

You want to make linux, you want to make a circuit, but regardless it just depends on each manufacturer and you need to read the installation instructions, so you know how it works. Okay, now smoke detectors right here you can have multiple heads. You can remove multiple heads. This particular one has dip switches back in this corner.

Where you can change certain things you can set it up for one or two sensors. You can change the tamper delay to seven minutes or zero minutes, so i currently have it set to zero minutes. You pull this off. It immediately goes into a trouble condition: okay, um! You can also turn the treble shutdown on and off so we can make it shut down the unit if there's a trouble condition again depending on the customer, the municipality.

You can do all kinds of things with these all right, so we have a test and reset station down at the office. We reset it from there oftentimes. You can have a fire inspector come through the building and he wants to test to make sure that the duct smoke detector is going to turn the system on and off like it should be. Okay, so we've got green leds indicating is all is good, so the fire marshal can go downstairs with this magnet boom.

He triggered an alarm okay. By doing this uh the alarm panel is going to go off. Maybe the enunciators are going to go off. Uh he's going to notice that the air conditioner shut down whatever, and you know then he's like okay, the system's working right so from downstairs in the office.

He can reset it and it can go back into normal operation if it's set up. Okay, i've got lots of more videos on duck smoke detectors on my channel. If you just google search on uh, either google or on youtube, just look up duck smoke. Detector you'll come across one of my videos.

If you want to throw in hvacr videos duck smoke. Detector, i can go a little bit more in depth. You can see me actually changing them, just like i did in this video okay. So i love having this trainer board.

I encourage everybody out there. If you have the ability to make one of these, it's not that hard, a duck smoke detector. What is you know? A couple hundred bucks transformer some wiring, and this is a great training board to help you understand - duck smoke, detectors, okay, biggest tip again. I want to go back on all these contacts are dry.

They are not powered from the 24 volt power source on the system. Sensor duct smoke, detector, okay, the supervisory contact is reversed, so normally close to common is, if it's in a trouble condition. Then it's normally closed to common okay, so in a non-trouble condition like we're in right now the contacts are going to be reversed, so common to normally open is going to be closed. Comments normally closed is going to be open.

The alarm contact is shown just like it is, and the aux contacts are shown just like they are, so it's really not too difficult when you're working on these, it's just a matter of breaking them down, systematically understanding what's happening and why it's happening. Okay, that's it in this situation. I don't know why they wanted the duct detector changed and i usually don't like changing things just because you know the alarm company said to do so, but i talked to management and they said yeah just just do what they said and i'm like, alright, whatever i Still suggested to management that they have the alarm company come and meet me, so i told management give me a call when they're gon na come. We can do a scheduled meetup.

That way we can walk through the system to make sure everything is a hundred percent. Okay, it's not uh completely insane for them to say that it has a bad detector. But to be honest with you from the looks of that detector, it didn't look that bad to me usually they'll be caked with grease and then i'm like, oh yeah, for sure this one though i mean it was a little dusty in there, but i didn't see Anything crazy but um. I went ahead and replaced it as the request of the management and went ahead and changed the sampling tube and the test and reset station.

I verified all my functions to be working correctly in my experience, oftentimes when we have weird problems like this like, if it's not obvious when i pull the detector apart and i don't see water damage or i don't see it built up with grease a lot of Times it can be their signaling devices. This particular one. I showed the signaling device. I've seen those things cause all kinds of weird problems now, at the same time, that signaling device was laying down on the bottom of the unit, and i went ahead and tied it up.

So that way, it's up off the ground, because if the drains ever overflow in these units, those signaling devices can get wet and that can wreak havoc on the alarm system and these customers, this particular customer in general. They don't do routine preventative maintenance. So we get overflowing drain calls all the time on them. That could be what was going on with it, but it's hard to say, but i did what i was asked to do.

Um you know, went ahead and changed the detector made sure it was installed properly. Uh and then you know the uh, the the description, the breakdown that trainer board, that i showed you guys like. I love it's right here. I love showing those trainer boards, because these you know, and that's that's the whole like goal of these videos.

The the whole youtube thing that i do is that i have a hard time learning things i struggle with things um. You know when i read technical manuals and stuff. Sometimes it just doesn't make sense to me. I have to get it dumbed down and then once it's dumbed down for me, then it makes sense and once it clicks, then i can learn what all the big words mean and all that fancy stuff.

Okay. So when i learn things i try to dumb them down just like, i have to learn them and explain things you know step by step and make them completely make sense. So this may not be the style me breaking this board down the way that i did for other people. They may just understand it completely, but i need something like this and i wish i would have had someone like this breaking things down for me.

That way. I didn't have to learn the hard way, the difficult way right. I can tell you that when we first started installing these duct detectors, we were doing some linux package units installs, like 2002, when i was first starting in hvac, and everybody at my company was confused. Utterly confused on these duct detectors, because every time we would wire them up, they wouldn't work right and it was like things were backwards.

Well, in hindsight, looking back on that, i can tell you what we were doing and we didn't understand that the supervisory contacts were backwards. Okay again, it took me forever to figure those out, but once i did, i became the person that always did the duct detectors and or always train people on how the duct detectors work. So sometimes you know the the way that the manufacturers explain in their installation. Instructions may not make sense to everybody and it may be difficult and for me, a lot of things are difficult to learn.

I'm sure there's some diagnosis there of some sort, basically saying that i'm crazy, but it is what it is right. I've learned to embrace it, and i just try to make these videos in hopes that i can help someone similar to me learn to understand how these things work, and so maybe they won't be so intimidated right on how these duck detectors work, because i can remember Opening some of them like in a shopping mall, that's something i'll say too. If you're ever ever ever, working in a shopping, mall do not touch the duct detectors. Okay, you need to make sure you get a hold of the security company and you need to make sure that you get a hold of mall management and or mall security, because they have multiple people monitoring that equipment.

I've opened up just simply taking a cover off of a duct detector, one time in a shopping mall and the trouble conditions set off the fire alarm turned off all the hvac equipment. In that section of the mall turned on all the emergency exhaust fans. The building went way negative, like the mall. It was nuts.

I was like what i i was so confused because i'm up on a giant ladder and i'm like what did i just all i did - was take the cover off and then but again looking back on that they had it set up and that's why i say You always need to understand how they're set up and configured they had it set up that if there was a tamper or a trouble situation, it triggered an alarm and that one turned on emergency exhaust fence if you've ever been in a shopping mall, when the emergency Exhaust fans go off, it's pretty crazy and in for those that do shopping, mall work, you know you're working on a long building right and there's these giant exhaust fans that are never running that you never understand what they're doing. Well, that's what they're there for they're there for fire conditions! So if there's ever a fire, they shut down all the hvac equipment that supplies air into the building, and then they turn on all these giant exhaust fans and what they're trying to do is slow down the potential fire they're trying to suffocate it right, because if You don't have oxygen as a fuel source coming into that fire or to help fuel it. You know it slows down the fire, so they turn on these emergency exhaust fans make the building go way negative in hopes that the building doors are shut, but that's a whole nother discussion to have about you know what people do if there's a fire they go And open all the doors and that's actually a bad thing to do, because you're introducing more oxygen into the fire. But i could talk about this for days.

It's just all weird stuff that i've learned, but just be cautious about the systems you're working on understand when you're dealing with fire alarms, whether or not you're legally allowed to get involved in them who controls them in my area, the fire alarm company does not change. Duct detectors, they call and say, hey have the hvac guy do it, but it's this weird gray area because they still have their wires landed in my duct detector. So we still kind of have to work together. Regardless i've been going off on a tangent as i usually do, i appreciate you all.

It's so humbling all the support, the comments, the feedbacks everything it's amazing. Thank you so, very much. Okay, if you want to help support the channel, there's several different methods to do so. The one of the ways is, if you're interested in purchasing any tools what you can do is i have an offer code with a company called truetechtools.com.

Now i purchase a lot of tools from truetech tools myself because they have a great hvacr selection, okay, but you need to do your research if you like what they have. If you like their pricing, i actually have a discount code. My discount code is big picture. One word will get you an eight percent discount and then i get a small commission from that now.

This is something new in the past. I would tell people to send me an email and i can generate an affiliate link. I have done away with the affiliate links so now i only have an offer code with truetech tools. Okay makes things a lot easier.

Saves me a bunch of time. So all you have to do is use my offer code. Big picture. One word: if you know anybody else that is going to purchase tools or if you want to share that, do me a favor and do so.

It helps to support the channel my offer code, big picture, okay, other ways to help support the channel. The easiest way is simply watch the videos from beginning to end without skipping through anything and without using ad blockers or anything like that. Okay, that's the easiest way. It doesn't cost you a little bit any money, except for just your time.

Okay, um, there's other methods. There's links in the show notes for you can donate via paypal, patreon youtube channel memberships bunch of different ways. Okay, i really appreciate you all. Thank you so very much and i will catch you on the next one.

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