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 gonna 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 gonna get this guy mounted um i do not have the sampling tube with me i'm gonna 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.

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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 gonna 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 gonna 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 gonna 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 gonna 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 gonna 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 gonna go ahead and there goes the blower so we know that the emergency shutdown and operation is working now i'm gonna 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 gonna go get my sampling tubes then come back as you're pushing in the sampling tube it does have an arrow onto it you wanna 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 gonna 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 gonna 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 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 okay

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