This is the smart buildings Academy podcast with Phil Zito episode 460. Hey folks, Phil Zito here, welcome to episode 460 of the smart buildings Academy podcast. In this episode, we are going to be continuing our technician onboarding series. And we're going to be talking about building automation system input types last wins, stay, we talked
about building automation systems in general. And over the next couple sessions, we're going to be going through input types, output types and the different tiers of the architecture. Then we're gonna move into electrical, then we're going to move into h vac, and then we're going to talk about
some basic building automation functionality. As always, everything, Val is going to be available at podcast at smart buildings academy.com Ford slash 460, I do realize I'm two episodes behind on uploading those to iTunes or Apple podcasts, Spotify and our website just been insanely busy. I just had a lot of stuff going on with the kids and work. But I will get those uploaded, as always, they'll be available on YouTube and Facebook and on LinkedIn. So a couple
housekeeping things. First off, we have our first Youtube channel member Thomas Trang. Thank you very much. For those of you who want to support the smart buildings Academy podcast on YouTube. There are multiple different member tiers that you can sign up for the highest tier actually has access to a discord that I'm in, that you can interact with me throughout the day, you can interact with one another throughout the day. But it's just a way to help support the podcast and the resources
that we dedicate to bring this to you twice a week for free. As always, if you find this valuable, please consider hitting the subscribe button and the notification bell on YouTube, sharing this on Facebook and LinkedIn by hitting the share and tagging at smart buildings academy or going to Apple podcasts or Spotify and leaving us a five star review. Like I said, today we're gonna be going through a lot of stuff, we're going to start off with a PowerPoint, I'm going to double
check that audio is coming in good. And on both LinkedIn and get on YouTube. And sounds good on Linked In. So let's get started building automation system input types. By the time you finish today's session, you're going to understand the common types of inputs. And identify the requirements of different input types, we're going to look at logical and physical inputs, we're going to look at a specification, how to read it, and then how to identify inputs, actually, what
type of sensors and devices you need to purchase. And we're going to talk about the logical inputs and what those are and what they entail. There's two primary types of inputs, I do recognize that these are called different things by different organizations. So I will do my best to be agnostic in the naming, do realize that depending on the vendor, they may be called different things. So please do give me some grace.
If I do not use the exact term that you would use. It's just because there's so many different terms to calling things in this industry, unfortunately. So I tried to be as generic as possible, there's two primary types of inputs. And those two primary types of inputs are going to be the physical Oops, here we go. We hit that real quick, the physical and the logical inputs. And the physical inputs are inputs that physically exists to connect the device to the
building automation system. These are going to be things like your temperature sensors, like your pressure sensors, your current switches, your current sensing relays, logical inputs are inputs that exist only in software to provide data and or settings for the building automation system. So this may actually represent a physical input that you get gather from maybe a chiller, or an air handler via BACnet or Modbus, or lon integration or, you know, MQ TT integration that's popular
nowadays. But at the end of the day, where you're looking at them, they are logical, you are not physically connecting to that chilled water supply temp. The chiller is actually connecting to it and it is interpreting it in its microcontrollers and sending it across some sort of communication bus to you and so the input you're seeing is logical. So those exist, like I said, to provide data and or
settings for the building automation system. Alright, there's got to be a way to turn off this pointer so I don't have to Keep going back to Slide Master. Let's see, we're just going to do the mouse cursor because it's easier for me rather than getting the pointer every time. And the grabbing the pointer just distracts me. We see right here, the input portion of a disk controller, we see resistive voltage, current contact and pulse, are the most common physical inputs. There
are other physical inputs. But these are the most common ones we're going to run into, may give you a representation of these. So there's resistive inputs, of which there's, there's really three types. There's thermistors, are TDs, and thermocouples. We're going to focus in on thermistors. And resistive temperature diodes are our TDs of the thermistors. There's a NTC. And PTC, you could argue that for RTDs, some
of those have NTC. And PTC does negative temperature coefficient and positive temperature coefficient, we can see a negative temperature coefficient right here. Actually, is this a positive 1am? I reading this backwards? I do not like this chart. No, no, no. I'm reading this right. Right. As resistance goes down, temperature goes up. Yeah, negative. I'm not good with math folks. Forgive me. NEGATIVE TEMPERATURE Kozik. A coat efficient. If I could speak, you think I could after
this many podcasts. As the resistance goes up, the temperature goes down. And as the resistance goes down, the temperature goes up, you will most commonly see negative temperature coefficient used with temperature sensors, although you will see positive temperature coefficients occasionally negative temperature coefficients are the most common. We can see, however, that when it comes to our sensors, not only is there different types, thermistors
RTDs, thermocouples. And each one has their benefits, and their cons. There's also what we'll see here, different types of sensing elements. The most common sensing elements are nickel or platinum, but there is copper, I don't run into it in specs very often. So what you'll see is that the platinum one has
a more predictive curve across a wider temperature span. Whereas you see, nickel kinda has a less predictable curve, it starts to tilt right when you get into this high temperature range, but let's be real outside of Steam, we're not dealing with a lot of things that require us to be less than zero Celsius unless you're doing like ice storage or cold rooms, or you know, something greater than 200 Celsius unless you're doing steam or you know your gap. Basically, steam is the primary
one I run into with it. Let's keep going. So resistive inputs, these are going to be a input that is used for temperature sensing, typically, I'm not going to get into constant resistance, but that is something you can use for different purposes. But that would just be confusing. voltage inputs. So this is an example of a electro pneumatic transducer. I use these all the time in a past life. And what it would do is based on a psi that it was reading, it would then go and send out an
electrical signal. So this was a way to go and control or sorry, based on the electrical signal that was reading, it would send out a pneumatic control signal, typically between zero to 15 psi. So the purpose of this was to take a pneumatic actuator and be able to control it with a direct digital control system. So as part of a pneumatic retrofit, those pneumatic
actuators can be 1000s of dollars. And replacing them may not be feasible, and you may want to keep it for whatever reason, maybe you're using it with steam, maybe you're in a corrosive environment where you don't want electromechanical actuator. And I realize you don't know what actuators are yet. If you're a brand new technician, don't worry, we'll get to that in the H vac components. But what you would do is you would take a zero to 10 volt signal, usually it would
come in right here. And that zero to 10 volt signal would be then converted transduced to a pneumatic signal. There's this little pump in here that would or there's a little valve in here that would regulate the control pneumatics signal or pneumatic air because there's main and then there's control. Main is your high pressure and control is typically your zero to 15 02 20 psi, this would be regulated by this transducer to thus control the, in this case, pneumatic actuator, or other
systems depending on what you're doing voltage inputs, right. So this is taking a voltage input. So what I want to be clear on, because this is something people get kind of crossed on a little bit is that inputs are not just to your controller, they can also be to an end device. So as we'll see, in next week's episode on voltage outputs, a zero to 10 volt output from your controller could actually go to a zero to 10 volt input on a
field device. So everything you learn about inputs and outputs can also be applicable to your actual control devices in the field. So I want you to kind of start to visualize, don't just be stuck on the controller actually think of your control devices, then we get to some current inputs. This is a humidity sensor, right, and we can see that this humidity sensor, this actually takes a power supply in series. So there's parallel and there's series. Typically, when you're
doing four to 20 milliamp it's in series. Typically, when you're doing zero to 10 volts, it is in parallel how you're wiring it up or could be in series as well, it really just depends. Once again, multiple different manufacturers do this multiple different ways. Some of them source the control power from their controller, some of them, there's just a variety of things. So if I'm not teaching exactly what your product does, do be aware that there are a lot of different products in the
market. Suffice to say, we can see the power supply going in powering the sensor, right, because this is current, not voltage. And if we remember from ohms law, which you have not learned yet, but you will in the electrical video that we will have upcoming probably a month from now that there is a relationship between current resistance and voltage called Ohms law. So as we pass through voltage, we can vary the resistance and allow the sensor to read the resistance on the
line. And that will then give us this four to 20 milliamp, there's a reason we do resistance it provides less interference, it also provides us the ability to have a longer run. So if you have to run a sensor across the central plant, and there's a lot of electrical interference you may choose for 20 plus four to 20 gives you some failover capabilities, which we'll talk about in a future episode. Then you have digital inputs, which are sometimes called contact inputs.
They're sometimes called dry contacts. I prefer the term digital inputs. And the reason why is because my input, what I'm truly sensing here is two states. It's either open or closed, it's either on or off, I'm sensing a digital signal, I'm not sensing a resistive signal, I'm sensing a digital signal. The purpose of these would be things like current sensing relays, a current sensing relay would enable us to go and I realized this is the current transducer with a four
to 20 output. But ignore that it was the best image I could find. So current sensing relay would sense current and then would close contacts based on that current to give status. And then you can actually set the current on that current syncing relay to a low enough current or to a high enough low enough to a low enough that it wouldn't be now hi, cheese men, I am awesome. I think it's the 45 minute run I did this morning, my brain is
still a little wonky. So longest run I've done it in a while. So
forgive me for that. You would set it higher so that it would actually show a load on the motor because if you had it trip at a low amount, you could have a free spinning fan, you know like the wheel or the belts broken and it's spinning and Charles just enough to trip the relay but not enough to show that it's actually running so on underload but suffice to say these digital inputs, not only current sensing relays These could be things like flow switches, pressors switches,
etc. So you know the AFS series 460 I believe maybe 465 From Cleveland controls is the resettable pressure switch that is a dry icon or a digital input It's a two state input that comes into your control and gives you a status, then we have pulse points. We don't, I don't see these as much anymore. Maybe you all do a saw them both in the electrical world, I also saw
them in the irrigation world. So a lot of irrigation and flow sensors would send pulses to tell you kind of what flow you are getting, you would also have electrical signals that would send you pulses. And based on the amplitude, and how often and how long the pulse was, it would represent either some sort of kilowatt demand kilowatt hours, and gallons per minute. And all of this is actually in the cut sheet for the sensor, it'll tell you and then when you go into your controller and set it up,
you would actually set okay, what is a pulse mean? How long does it mean that and this gives you an ability to calculate either electrical or hydronic flow. Then we get into logical inputs. But before I do that, I actually want to switch screens real quick and show you something. Here we go. You should be seeing a specification now. And in this specification, I've focused us in here on this outside air, so this is Oregon State University's they call it a guide spec, but it seems to be
for a specific project. What you see right here is humidity and temperature sensor 2% accuracy thin film capacitive capacitive replacement sensor element with replaceable sensor element with waterproof housing, 10k Ohm type two, and a two wire loop power four to 20 milliamp signal. So it looks like we are getting two signals 10k Ohm type two is a thermistor. It doesn't specify whether it's PTC or NTC. And it also says two wire loop powered
four to 20 milliamp. So I'm assuming that that is meaning two things, one, four to 20 milliamp back to the controller for the humidity signal. And loop powered, is just showing kind of the electrical details I showed you a little bit earlier. So you're sitting there, you're reading the spec, you just got sent out to a job, you've got to go to Granger somewhere to pick up a sensor. How do you make sense of this? Well, the first thing, this is where we go back to those input types I just
showed you, you have a resistive input. So the first thing I'm gonna do here is I'm gonna figure out what inputs do I need? Well, based on this, I need a resistive input, which is 10k type two. And I also need a four to 20. Just through my own experience, I know that humidity being a linear scale of typically zero to 10 is typically, or sorry, zero to 100 is typically zero to 10 volts DC, or two to 10 volts DC, or
four to 20 milliamps. Those are the typical input signals to the controller, and then I scale match those to my humidity using like a reset or a scaler, whatever it's called in your control system. And then I also see my 10k type two, which I know is going to be a two wire resistive, and that's going to go to a resistive input on my controller. So from there, I would go to and for this, I'm going to be using Kelly right here. And I always feel like I'm pronouncing their name wrong.
But I'm gonna go to their site. i We don't endorse any company, I just, they have a pretty easy site for me to navigate. I've ordered a lot of stuff through them. And but you know, your distributor or controls provider or parts warehouse of choice will most likely have the same equipment. But what I do here is I type in I typed in outdoor air humidity. And now I start looking at this trying to figure out what do I need, I know I need 2% accuracy. That's important. I know I need a tank
a type two thermistor. And I also know I need a four to 20 milliamp signal. So can I find any of these that have that? I'm going to just click on this one right here because it says 2% and I'm going to see what it has as far as capability. So it has a 10k type two thermistor Okay, great. That covers me for that. And it has a four to 20 milliamp output signal. I typically like to go and look at the actual manual itself, which I will
bring up right here. Give me one second So 2% of K 10k, type two, so that's e. So I'm getting my part number here, I want four to 20 milliamp This is universal, so two wire or three wire, and it also do zero to 10. If I didn't want the display, if I wanted to save money, I could do the X and not get the display. I verify that it's zero to 10, I verify that it's got temperature, I verify what I need for a power supply. If I'm going to do four to 20, I need a DC power supply. That's what I
need. I go in here, verify my accuracy, okay. And everything looks good for what I need. And so now I've gone and I've figured out, alright, this is what I need based on that specification. So I hope at this point, you've seen me go and take what I know about my inputs, take what was in the specification, which I'm gonna bring up again, real quick. Here we go. Identify what I need. And you'll notice the sensor that I
chose is not listed on here, but it says or equal. So that typically, not always, but typically, if it says or equal, that means that I can just substitute it in, I don't have to submit an ad alternate, I can typically just put that in some engineers of record or equal will mean they still want you to submit an ad alternate. So just your mileage will vary. Know your engineers know what they expect. This would be a good
time, real quickly, though, to talk about two things. One, will be speaking at Niagara Summit. So if you're going to be at Niagara Summit, definitely stop in for our session on recruiting, training and retaining. So we're gonna have our director of business development, talk about our approach there as part of a panel. That will be on Wednesday, April 17, at 11am. And then we're also going to be doing an episode episode, a panel on cyber fluency for the
OT environment. So we're going to be talking about cybersecurity specification, all of that will be on that panel as well. So I hope to see you there. And I'll share that one with your real quick cyber fluency. So I hope to see you all there. Let's get back to the PowerPoint. Here we go. And back to the PowerPoint. So logical inputs, there are two primary forms of logical inputs. And they go by many, many, many, many different names. Some folks, as you'll see here, call
them Numerix and bullions, and strings, and E neumes. Some folks call them multistate, some folks just come straight up aisb, eyes, AOSP, vos, aviz, EVs, etc. For the sake of this presentation, and my sanity, we will focus quite simply on writable and non writable inputs. So writable inputs are inputs of which someone can write to the input, and this is where it gets a little muddy. I'll admit that, because you can have non writable inputs that are still writable. They're just
not writable by the operator. So for example, I can go and add a numeric point but have it I can add a point. That's an AI, for example, by mapping it in, it is a logical point, it's writable, from the chiller that I'm integrating it from, because I'm mapping in the point, but it's not writable from the operator, so I can't override it. And I know some of you are going to be like, Well, Phil, there's a variety of ways you can override API's analog inputs, or binary inputs by bringing them out of
service. You are correct. But I would argue that that's for testing, because technically, when it's out of service, it should be out of service and no longer readable by the controls program. But that's, you know, nuanced. Then there are writable files and the reason these are writable is because they have a priority array a priori array is a more advanced concept that
we'll get into, when we start to talk about BACnet. Although the priority array is not necessarily a BACnet construct all it is is a multi point array of which the highest number of inputs 16 is of the least importance and input one is of the most importance. Some folks do a zero to 15 Priority array I primarily though See a priority array of one to 16. So 16 is typically is how it goes, typically is 16 is global 15 is local 14 is local operator. And then eight is operator override.
And one is like emergency override. So there's some kind of standards behind what should be what. But, you know, the most common standards are just 16, and eight. Now, here's the
difference. Or here's the important part of this, if you're going and I've discussed this ad nauseam, for those of you who have listened to our podcasts in the past, if you're doing an integration, a BACnet integration, and you map in an analog input, an analog input, or binary input, or a multi state input, and its zone temperature, or its chilled water temperature, you map that point in, I've seen a lot of people map those in and think that they should be able to
command them. Those are not writable. They're not logical, they're not variables that are controllable. And so if you map in those inputs, you're not going to be able to edit them inputs are typically logical inputs are non writable. And they're for data reading purposes, only writable inputs, also known as variables, see here, analog variable, or analog value, or numeric writable. In Niagra, they basically all mean
the same thing. They're just different systems, different naming structures, those have a priority array, and thus the writable. And a little bonus point, the objects that are known as outputs. So in Niagra, world, it would still be called a numeric writable. In other systems, it may be called an analog output. Or it may be called a voltage output. And those are actually writable. Because those typically have a
writable array as well. All right. So there you have it in a nutshell, those are inputs, I started off this episode with saying that you'd be able to describe the common types of
inputs. So you should be able to describe that there are physical and logical inputs, that they're resistive voltage, current contact impulse inputs, and you should understand why and how and when you use those, even if you don't understand exactly how to implement them, you should also understand that there are logical inputs, and that those logical inputs are either writable or non writable. And that the writable inputs, they're writable, because they have a priority array. So there
you have it, folks. If you haven't, definitely go and check out the rest of our podcast episodes at YouTube. If you want to be like Thomas, and become a member, we greatly appreciate that it supports the podcast that we deliver to you every week, I will also say everything will be available, eventually, at pockets that smart buildings academy.com, four slash 460. My goal is to get all three of those episodes up this week, because I know we're still waiting on 458 and 459 to get
uploaded to the website that's on me. And definitely, if you found value in this, please consider sharing it on your Facebook or LinkedIn by hitting the Share button tagging at smart buildings Academy, or going to Apple podcasts or Spotify, leaving us a five star review or going to YouTube and subscribing. Definitely appreciate all of you so very much. Next Wednesday, we're going to be diving into physical
outputs. And then after that, it's going to be a recorded one because I'm going to be at Niagara summit, but we're going to be talking through controller types. We're gonna talk through application specific versus free programmable controllers. And we're going to get a little into BTL classifications of controllers. And we're going to talk through that. And then we're going to go through the week after communication buses, the week after that, we're going to go through router slash
supervisors. And then we're going to go through servers, and that should take us through the four tiers of the BAS architecture. And then we're going to move into h fac, I think maybe electrical. So it's either gonna move into h fac, or elect, then electrical or electrical and HVAC. It just depends on the questions I get. I'm going to pause here. Any questions you all have. I'm an open book. I really appreciate you all being here. And I will answer any questions you all
have. Just feel free to ask and I would be more than happy to answer whatever questions you all got. And with that being said, let me stop sharing that. And let me see what questions we have in the chat. I hope you all are finding these valuable. I know it's a little basic. And I know I'm starting off at a
pretty simplistic point. My goal is that by the end of this series, which I envisioned taking about three to four months to get through, so about 1216 ish episodes, there should be a solid foundation that I'll then put into a playlist that you all can go and share amongst yourself. And hopefully, it just really helps upskill the folks who are trying to learn this, I also plan on doing some YouTube shorts that I'm going to talk through the industry, just why I believe young people should join
this industry. The benefits of that. Let me see if there's any questions on LinkedIn. No. I know LinkedIn is kind of funky sometimes. And sometimes the questions sneak outside of that. No, okay. They're not there. YouTube, not seeing any questions there. So we're good. All right. Well, hey, folks, everyone, I appreciate you. I will see you on Monday. I honestly don't know what episode we're going to cover on Monday. I'm kinda torn between where we're gonna go with that. But
for sure, Wednesday, we're going to be talking about outputs. If y'all need anything, hit us up on LinkedIn, hit us up on our website. And I hope to see you all at night or Summit. Thanks so much. Take care