The Truth Behind Shielded Cables, Programming Logic & HVAC Controls for Techs – Patrick Butler Part 1
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What's up guys, welcome back to the podcast. So we got Patrick Butler who goes by Professor Butler on TikTok. He's got a lot of good videos and his account is blowing up in numbers. So go check him out. So what we're going to talk about here with Patrick is building automation and how a an HVAC tech that doesn't really have a ton of building automation experience. We're

So you can better understand it. And I'm going to tell a story how a building automation guy and myself got into a bit of an argument because he thought his trade was above mine. Guys, we need to work together equally to get through and solve problems. So no trade is bigger than the other. We all have our own part. So let's get to part one with...

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All right. So Patrick, let's get into, let's get into the conversation. You're a commercial tech. So am I. You have experience with building automation. I've got a little bit enough to hold a conversation with you. Like I know about it. I've done some install, some troubleshooting. I've done some coding, uh, very, very minimal at that. To be honest with you, I did like a full week course. Wow. 16 years ago.

on reliable controls out of Vancouver, BC. I did a course on that a while back and got into that a little bit. But let's have a conversation that weaves in commercial

HVAC weaves in controls because controls is a big part of commercial HVAC these days. Sure. And let's weave in teaching methods of today versus yesterday. Right. So building automation at this point in time, capabilities like we can do pretty much anything, right? Yeah. Well, so usually from my experience is that people that get pushed towards the building automation section of our trade tend to have, you know, computer skills, you

and usually have an electrical background. So it could be as far as, you know, they started off as an electrician's apprentice or electrical, or they were in the fire alarm.

You know, access control, things like that, where they're already working with low voltage and they end up going into either through people they meet in the field or just a complete change. But that's the least experience that I've had. People always said, oh, yeah, I got my start in, you know, data, Ethernet. And they kind of work their way towards commercial controls.

I do feel it is a very advanced part of our trade. When people hear controls, they tend to think low pressure control, high pressure control, basic unitary controls opposed to a control system.

fully automated control system for a building. Yeah. Sure. For energy saving, right? You want to say the customer wants to save money and they want to be able to monitor their equipment and systems and especially trouble. If you have a data center or a hospital, you need to know if a chiller went down or if, you know, the boiler plant is not operating. So in order to do that, obviously there's ways of wiring and implementing things to make that happen for the customer.

Yeah. Let's talk about, maybe we can give, so there's people in the audience that have not seen building automation. They've never touched it. So maybe after, I'm going to give you, I'm going to tell you a little funny story.

about a control guy and me being a tech on site and the argument we got into was, it was pretty funny. But, um, maybe after I'm done that we can take, we're going into cooling season. So maybe we can take like a small plant, a small chiller plant, a chiller, a couple of pumps and some controls and talk about how we tie the controls in to run the chillers, pumps, et cetera, just for the audience's sake. If you don't, if you want to do that, right. If you don't mind. Sure. Cool. So

I find the best controls technicians know the trade of HVAC from a mechanical standpoint really, really well. They're usually the best when they get into controls and learn it because they understand the mechanical side. Then when they understand the controls, they know both.

So I was dealing with this heat pump and I probably told this story before, but the seat pump was in a ceiling. I was told there to go, um, make a repair for it. And after I was done making the repair, I wanted to be tested from the building automation side. So I tested it myself, right? I had jumped it out, cooling, jumped out, heating, fan, all that stuff worked properly. Okay. And locally you did that. Locally I tested all that, but.

I'm like, you know what? It's, we should get the controls guy to test it. So I called him up. He says, yeah, I'll test it tomorrow. Cause he couldn't test it off site for some reason that day. Anyway, so he comes to the site the next day and he's like, he calls me and he says, Hey, when I, um, when I run it in cooling, it's actually heating. When I run it in heating, it's actually cooling.

I said, well, that sounds to me like it's just a programming change that you can make. And it should be fairly easy because that heat pump works fine. And then he started to argue with me that I messed up my work and he's made lots of money off of mechanical guys and stuff like that. And this guy was like, he had his back up against the wall, like a chip on his shoulder. And I didn't know what his problem was, but it's

Sounds like ego. Ego gets in the way of people. He did not understand the mechanical side of the trigger whatsoever. So as I'm explaining it to him, you could kind of sound like he was a little timid to speak. And then all he could come out with was anger. It was the only emotion he had. And I said, just do me a favor. I said,

Just do a control change, a little code change or swap around some, some, uh, some outputs from your controller to that machine and just reverse it. And it'll be fine because I've tested it locally and it's good. I never heard from him again, but anyway, the, the argument was funny. So let's say we got like a little small chiller. Let's say we've got a couple of pumps and we want to control them. Let's say we want to, um, control the chiller based on loop temperature. Yep. Chilled water at that point. Yeah. We want to control the pumps, uh,

based on like a lead lag situation or what you only need one. So it's basically duty standby. We have one running and one on standby and then they switch over like every week or so to keep equal runtime. So maybe take us through a small system like that. Sure. So if let's say here, we're going to need some data points, right? We need to know that you're going to have the chiller as a mechanical piece of equipment. Then you have your pumps and then you need some type of controls, either external or

to the chiller and the drives for the pumps or starter, you'll need some type of, you know, DDC. Okay. The chiller, now you can either control it two ways. You can do it with a, like an analog signal of DC voltage. You said DDC. So...

People are going, what the heck is he talking about? Sure. Direct digital controls. It's another word for, you know, a controller in general. People will say DDC, you know, they may, there's a few different words, but yes, DDC is an acronym for direct digital controls. Okay. Perfect. Yep. So you need, you need some type of brains to interact the two, to do the handshake, right? Because you have two pieces of equipment that are separate.

Your chiller, we're going to monitor for alarms to make sure it's operating properly. And we're going to be feeding it a set point, right? We want to know what temperature does the building need for a demand. If it's a day like today here in New York, you know, the sun came out, it got to like the low 50s. You don't need to run 40 degree water. You may just do, you know, 48 or 50 degree water to satisfy the load. So the chiller, again, is going to be told to come on. It

by the BMS or by an outdoor air temperature sensor saying, hey, it's cold enough. Let's operate. Let me stop you there because I want to paint a visual for the audience here. So

in the room we got a chiller and so far uh we're controlling that chiller based on a chilled water set point and so basically we could have like an electrical box in a mechanical room there'd be a controller in that electrical box that controller would be powered with 24 volts

the most minimum simplistic way to do this. We run a sensor from that controller out to the chiller supply line, chiller return line. We could do both or both or both. Right. And then a flow sensor, right. To make sure that we have actual water moving flow sensor. Yeah. We could also have like an operator, like it's, it's tied into fire alarms or something like that. So if the fire alarm goes off, it cuts power to everything that, that happens once in a while with equipment.

But we could have all these kinds of things, but it starts with that controller based in that box. We send our sensors out to whatever we want to sense. Those sensors will give the controller feedback. Feedback, yeah. And it will decide what to do based on the program you've written it. And then if it says, hey, chiller, come on, we're going to send...

outputs from that controller from the controller to the chiller. So we got inputs coming in from sensors and outputs going out to devices like chillers, pumps, et cetera. Right. Am I right on that? And you could have, so back to the controller real quick, you could have two different types of controllers. You have a programmable controller where all the logic is written by a programmer or controls technician, or you can have what's called an application specific controller, which

which it's designed to run a chiller, not part of the chiller, but it's a module that has everything in it to run the chiller. And then you kind of plug and play with the sensors it needs and the inputs and outputs that are needed. Yeah. Yeah, it makes sense. Just like a boiler, you could get a boiler control and it's already set up for a boiler. You just got to make some dip switches

or whatever, right? Yeah, like a reset controller or something like that. Yep, absolutely. Same type of difference. That would be an application specific because it's made for a specific application. Correct, correct. So...

the chiller we got the inputs we got the outputs to the chiller if we want to run the pumps we can send outputs from the controller again to like you said a vfd or potentially or a starter or a starter and we would obviously have a written piece of code for that or if it was application specific maybe it's just a couple dip switches or a couple of inputs inside of it to turn them on but it's

Essentially, it's very simple. It's like having, imagine a circuit board in a furnace. It's very similar to that almost, right? Because a circuit board in a furnace takes inputs in and it has outputs that go out to like induced fan motors, indoor fan motors, stuff like that. But the inputs that come in are from like safeties and stuff like that, limit switches and all that. Basically, all circuit boards that are involved in what we do is just inputs and outputs, right? You have inputs.

In the board, you have what's called like a chip itself is a microcontroller. It's like logic. Yeah. It's the logic. Okay. So you're getting input and output, right? You know, input in output out. So whatever you're doing with those, again, is based on whatever your needs are.

And that's how every circuit board in our systems work. And I studied electronics because when I got into trade, I would walk up, I'm sure to you as well. You would ask a journeyman or lead technician like, hey, what's that board? Oh, that's just the furnace board. Well, how does it work? It just does whatever it does. It's ones and zeros. You know, they didn't really understand how the board worked. Well, me, I'm like, I want to know how it works.

And so I started studying electronics to help understand. And that's how I found it's like, they're all basically the same if you break it down to its core. Yeah, for sure. One of the points that we should touch on is when we're expanding out to multiple controllers controlling multiple pieces of equipment. They all have to be like, I've sat in the basement of a high rise. You turn on the computer and you can see like

everything in the building. You can see the, the set points, the room temps, the suppliers, and just for, for everything. And it's, it's crazy when it's all working right. It's really cool to just sit there and you can actually go through and find issues that someone might not know exist yet, but you could find them through different alarms and set points or, or,

And we also do preventative maintenance on BMS, on building automation systems or building management. Yes, we do. Where just like an equipment PM where you go in and you're checking, changing filters, belts, trying to prevent issues. We do, you know, building automation PMs where we go in and look at the system to see if we can see something that may be trending bad right there. Because you can make trends of graphs of data. You can look at it and see, hey, wait a second.

Why is the chilled water temperature rising all week? You know, what's going on? And then that's how you can look mechanically or that's really where it's strong suit is, is not just operational, but it's saying, hey, you know what? Maybe we need to go clean the strainers or maybe we need to, you know, do some type of maintenance on the water side.

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Yep. A hundred percent. And, and what I'd like to talk about is the fact that we have to connect these pieces of equipment with their controllers through a network, right? And we have to wire that network almost like daisy chaining, uh, these controllers. And I didn't know this when I was, when I, like I've wired up, like when I started to do a bunch of Mitsubishi stuff, we had to network them together.

Yeah. And I mean, I didn't understand what shielded cable was back then.

I had no, I'm like, oh, it's just got foil insulation on it. Cool. I didn't know what it was for. They just cut that off. They cut it off. I didn't know what it was for. And sometimes, yeah, you would, that ground cable that's touching that aluminum shielding, I would sometimes cut it off until I understood what, what it was for. Sure. So let's talk about shielded cable for a minute that ties in these networks or ties, creates the network. I have a good story about it. Okay. I got it.

All right. So shielded cable, when you're dealing with any type of controls that are on that, you know, that are communicating and that goes for, like you said, VRF systems or, you know, mini split systems that are communicating or even, you know, a home split system that's communicating the voltage that's on that on those wires. We call it a communication bus. OK, the two wires.

The DC voltage is very low. Okay. So it could be up to like between zero volts and 2.5 volts DC. So that's not a lot in the, in the grand scheme of voltage.

So now imagine that cable is laying on a fluorescent light or near an electric room that has a bunch of transformers that are creating electromagnetic fields. Well, what do you have when you have a electromagnetic field near a copper conductor, right? You induce voltage, right? You create voltage can be induced onto that cable. Yeah. So the shielding is acting as like a Faraday cage, which is preventing any type of penetration from, uh,

electromagnetic forces around the cable or wherever the cable may run through. So the first time I did a job that it really mattered on what's called, there's different protocols that things communicate at on building automation. And it's basically a set of rules that that voltage follows to transmit that data. There's BACnet, Modbus, Lonworks, there's a few different types and they all have their own set of rules.

So I was familiar with Lon where you didn't use shielded cable. It didn't require it for its protocol. So when we did our first BACnet job, I ran the daisy chain comm link the same way I did.

Well, the engineer, application engineer for controls, ordered all this shielded cable. And I was like, all right, I just wired it as I would, white on positive, black on negative, and the shielding and the ground I just cut off. Well, now I ran this across this whole factory, across the whole ceiling, across the whole factory. And when I went to commission it and turn it all on, we had data dropping out left and right. Nothing was working and we couldn't figure out what it was.

And it turned out what we created was a giant antenna. All that wiring run throughout the whole building was just picking up EMF from all over the building. It was getting into the cable, acting like a antenna and was destroying our signal. We had no communication. So we had to go back, trim the cable back.

And then take all of the grounds, wire them together, splice them together, and then drain it. Now, what draining is, is you ground it and bond it to the controller. Usually at the beginning of the link where the main controller is, you ground it.

And at one side, the other ones are just spliced together and taped back all the way through from your first device all the way to the end. Yeah. If you connect them at both sides, you can get something called an earth ground loop. And the voltage kind of can get confused on where to go. And it can kind of just like circle and then not drain to ground like we want. Yeah. So I didn't do that, but.

On one of the first Mitsubishi jobs I did, or maybe the second or third or something like that, because I think in the first couple, I was just cutting that, that ground cable off. Then we started to, when we daisy chained our network in, I was grounding that cable at every single point.

We never had problems with it, but I didn't find out until I went on the reliable controls course that yes, like you said, you ground that at one spot, one spot only to drain any interference that that cable might be seeing from outside sources. Like exactly how you explain.

And it can be anywhere along the link, but we tend to do it at the main panel because that's where everything's starting. And if a technician goes to a building for the first time and they open that panel, they're going to see that it's okay. The shieldings are done and we're drained. That's why we do it there. For sure. Cool. So, I mean, that's kind of like a quick introduction to building automation. You could go way more in depth. We could, I'm surprised there's not like, maybe there is a building automation program

podcast that just talks about building automation because you could talk about that for a while. There is one guy on YouTube. I forget his name, but he does have a building automation YouTube and he does like solo podcasts with your videos explaining things. I can get you his info, but he was he's really good. It's just a very broad topic. And a lot of people say, oh, I want to do controls or I want to do, you know, BMS work.

but where to start, right? And like you said, Garrett, start in the beginning. Be a technician. A technician, when you understand how systems operate and you understand sequence of operations and how these systems work, integrating them into a building automation system and then commissioning it, it makes it so much easier because now you know what's supposed to happen and when. Yeah. No, you're 100% right. So I, last part, I'll just say this before we move on because I want to get your take on this.

education past and present as we discussed in the beginning i find it it's not funny it's just interesting because a lot of the stuff that we just talked about it's moving its way into a lot of the residential stuff like sure capacitors and contactors are becoming a thing of the past in an outdoor unit heat pump air ac whatever it is they're getting smarter they're coming with um

application type controllers, inverter technology. Inverters. And the residential guys, they're freaking out. But what some of them don't know is this stuff has been, and I just said it to someone on a podcast or two ago, it's been in commercial for decades. Sure. It's just moving into residential now. And it's worked.

fine there. You know what I mean? It's been proven to work. And a lot of these resi guys are freaking out. So if you have some advice for a residential tech, that's never seen something like this is used to contactors and capacitors, what's the best way to make that transition to understanding more of this stuff? So a lot of the videos that I make, I, I look at things like that, right? Where, what are topics that are becoming more

in different parts of the trades and seeing more guys that are in like the warmer climates of Florida, Alabama, you know, here in the States, um, they're seeing inverters and they're like, Oh, I don't want nothing to do with that. What I did, again, I'm going to speak for myself personally. And what worked for me is I started to learn electronics. Um, there are these little boards that are called Arduinos and they're very small. They're very inexpensive. And it's a microcontroller just like what are inside circuit boards. And it comes with a kit

Like those electronics kits we had as kids with light bulbs and stuff like that. But this is on the microcontroller level. And they sell these little kits that have sensors, LEDs, little motors, things that you can take and write the code, wire it and watch it work.

and that's how i started to learn and there's so many videos on on youtube and all over the internet on how to do this it's very simple and that really gave me an understanding on on what's happening in these controllers and that literally it is it's just voltage and it's controlling voltage on you know the voltage levels how much the quantities and it's not as bad as you think and i know it's intimidating you see there's all these circuit boards whoa

A lot of it, when you look down, is power boards, right? You're filtering the power because these controllers want clean power. So you have these big capacitors and big, you know, inductors. And you're like, whoa. Mostly just cleaning your power up, right? Making sure it's nice and clean. And then you're controlling it

how you're, you know, without getting too technical, the frequency, right? At least the change of positive to negative, like here in the States and 60 Hertz per second, right? You're 60 cycles a second. Inverters just control that of how slow you do. And when a motor gets that, it can go slower or faster. And the circuits that do it are pretty simple. And they just packing it into one board.

So I think learning electronics and watching some videos on the internet will really help you understand that they're not that difficult and not that advanced as you might think. They're just intimidating. Yeah, I agree. But you got to get your feet wet in order to understand. Ask questions. Yeah, you got to watch, ask questions. Just do what you can to gain as much knowledge as possible.