Episode 282. Danfoss CO2 Controllers with Dave Yoder

I think I do appreciate when they tell me up front that I don't know. I don't know this or I don't know that, or I, I'm not familiar with this control. Even if they say, I don't like your control. I'm okay with that because then I know where we're at and then I know basically where to start them with

There's still some of that out there, but that's where I got my start was there 10 years and then we were acquired by Dan Foss and that was 25 years ago, basically. So I spent a lot of time in tech support and going out into the field as well because you know how valuable that is. And yeah, so a lot of, a lot of field time and then a lot of tech support time learning how to ask the right questions, how to sense the frustration in someone's voice and figuring out how to help them and then trying to frequently turn a negative into a positive by doing a little training with them while we're on the phone.

There's still some of that out there, but that's where I got my start was there 10 years and then we were acquired by Dan Foss and that was 25 years ago, basically. So I spent a lot of time in tech support and going out into the field as well because you know how valuable that is. And yeah, so a lot of, a lot of field time and then a lot of tech support time learning how to ask the right questions, how to sense the frustration in someone's voice and figuring out how to help them and then trying to frequently turn a negative into a positive by doing a little training with them while we're on the phone.

But when you have a controller and a full control system, it there, there's more to be asked than being answered right away. Cause I, I'm sure a lot of people will call up and you probably seen this over the years, they'd call up and looking for an answer right away on a question that there's many more questions that need to be answered first.

Right. Right. Yep. Yeah. So yeah, I have to ask lots of questions to find out Rolling on and it's a matter of asking the right questions and kind of asking leading questions to get those little details that help me piece together what's really going on. And I've been kind of lucky really, because in all those years in tech support, Dan Foss and even ECI has allowed me to kind of see it through, not just get the call, give an answer, get off the phone, get to the next one.

They let me see it through to the point where I can say, Hey, did that really work? Did that fix that problem? Because then I'll remember that for next time. What are, this is, this is a good, good thing. What are some things that over the years, cause you've done so much technical support, what are some questions technicians, if they asked a little differently, or maybe in a different way that would really help you, you as a support expert.

In the field, if they call anyone, even they're calling their lead technician, you, cause this is what a lot of it is. A lot of apprentices and they get hired on and they start for a company and then they rely on that lead technician and then a lead technician could kind of get frustrated, right? Right.

Like, Oh, you're already, you're in, you've been in the refrigeration engine for four years. And you know what I mean? You're asking me these questions. What are some of those questions that if say a newer technician or even a more experienced technician asked. Would really help that conversation go quicker, better. Well,

But I know kind of how, how deep in to start with them, because if the guy says, Hey, I've been, you know, I'm pretty familiar with this stuff, I can do calculations, then I know, okay, we're going to the advanced level right away. And then I can start. Kind of probing around and see what have they tried so far?

But I know kind of how, how deep in to start with them, because if the guy says, Hey, I've been, you know, I'm pretty familiar with this stuff, I can do calculations, then I know, okay, we're going to the advanced level right away. And then I can start. Kind of probing around and see what have they tried so far?

And also, um, like, is there anything for me to teach this guy while we're at it? Because you'd be surprised how guys work with this every day, but there's, there's little details that can be missed. Like for instance, a guy said, Hey this controller, just the fan relay or the, sorry, the fan delay is not working on your case controller.

Two or three conversations later, we realized that he didn't really know how it worked. And he didn't, he didn't, he didn't really know because no one showed him that, hey, it's a time and a temperature thing. And he thought that it was one or the other. And that if you set the delay to zero, that meant it ignored the delay. So. Yeah. It's those little things that you find out that you can't assume that they know all the answers just because they've been around it for a while.

Yeah. And that's, I think that's the key too, is like, I've been training so many people, like, just like you, you've trained thousands of people just like me. And over the last couple of years, just diving into people. Okay. I've been doing this for 10 years, you know, doing supermarket refrigeration. But when you dive a little bit deeper, it's like they, that's how they were taught and it worked. But there's always that fine detail. They're like, Oh, smoke, Trevor. I, I, I was, I was fixing this all, all these times, but I did know that's why.

Fixing the problem, you know, that the underlying thing, which you're kind of talking about there, which is so cool. Yeah.

Yeah. Yeah. So then a couple of years ago, Dan Foss said, Hey, let's take some people and put them let's assign them to accounts as an application engineer. So that's how I got involved with some of the bigger accounts like Ahold and Albertsons and, wise markets and shop right in the, here in the States. And so that was I wasn't sure it was a good thing at the time, but it was a good thing because I ended up going to the West coast four times last year to help with CO2 startups. And so that was an opportunity for me to learn and for me to teach at the same time and kind of see the whole puzzle come together, both on the K side and the RAC side.

And it's been, it's been a good experience and it gives us a chance to say, okay, this is how Dan Foss does CO2. This is how it all comes together. And then when the RAC's not running, here's where we start.

Now there's some differences. You know, so you're learning along the way. And just when I talk about technicians in my training program, if you're there with the expert, like from Dan Foss, they're still learning too. They're the expert, but things are, things are changing at such a rapid pace that we're all learning.

Now there's some differences. You know, so you're learning along the way. And just when I talk about technicians in my training program, if you're there with the expert, like from Dan Foss, they're still learning too. They're the expert, but things are, things are changing at such a rapid pace that we're all learning.

And it doesn't matter if you're an expert in any big manufacturer. We're all learning as we change and evolve with CO2. And this is what we're going to dive into today. So you started in CO2 years ago, learning about it and controls, but really diving in now over the last couple of years in transcritical CO2. So how's that experience been so far? So working with, let's start with working with the contractors on this.

We think we're going to have this thing running in three days. So what's, you know, where do we start kind of thing. So it's been good because yeah, we can get, we can get some training in and we can explain, and it's answering, as you know, it's answering a lot of questions like Hey, why isn't this case running?

We think we're going to have this thing running in three days. So what's, you know, where do we start kind of thing. So it's been good because yeah, we can get, we can get some training in and we can explain, and it's answering, as you know, it's answering a lot of questions like Hey, why isn't this case running?

Why is our superheat low? Why is all this happening? And I can say, okay, here's where we're going to look. And fortunately the controller allows us. to customize screens for them, so when they log in, they get an overview of everything. The critical pressures and temperatures and valve opening degrees and stuff like that, so that if they're completely lost, they can log in, they can see all that on one screen, and then I can start asking questions if they come to me.

And say, what's going on with this thing. So that's been good. But yeah, it's answering a lot of questions. And running through startup sequences and stuff like that. To say this is what you should expect. And if this isn't working, here's what you can test with your meter. To see what's going on with it.

And I totally agree with that because I consistently talk about that when I'm, I'm working with a contractor or technician, I'm like, you gotta, you want to work with the manufacturer and get a better understanding. Cause yes, maybe there was a parameter that is not the right one that the OEM of the equipment put it in or was recommended, but was never looked at.

Going down the road when they added heat reclaim or something, or if they added something else to the system as they evolve it. And this is where it's so important to ask those questions. Cause when I go to a field startup and I'm with the manufacturers and the EMS and the control guys, I'm like, this is the time telling the technicians to ask the question, but they're like, well, I got to do all this work, I got to pull wire, I got to totally understand, but usually you're there for a couple of days and in that couple of days is ask those, those questions and build a relationship.

With those people, that's how, how you continue to grow and learn and offer offer. I think, I think the biggest thing is saying, I don't know, and what can I do next? How can we go forward with this? Yeah. Yeah. And there's a lot of situations where fortunately I've been working with the same crews sometimes more than once.

With those people, that's how, how you continue to grow and learn and offer offer. I think, I think the biggest thing is saying, I don't know, and what can I do next? How can we go forward with this? Yeah. Yeah. And there's a lot of situations where fortunately I've been working with the same crews sometimes more than once.

So by the time I get to the next one, it's different. Do you feel that these electronics are helping? The industry grow their knowledge and people in the industry, or is it slowing the, the, the growth of them down? I guess that's all I think. I So by the time I get to the next one, it's different. Do you feel that these electronics are helping? The industry grow their knowledge and people in the industry, or is it slowing the, the, the growth of them down? I guess that's all I think. I

I think in the short term, it gets frustrating for guys because there's so many transducers to think about. And and I sit them down and before we start the rack, I say, Hey, we're going to check all the transducers on the floor. And we're going to make a list of the ones that are not reading, and we're just not going to start those cases until we get good readings there.

And I explain why, because typically that will set you back with low superheat and all sorts of issues. And now you've got to chase that down. But I think I think if you use all those tools, then you come out ahead. But in the beginning, I think it is frustrating with guys because they just feel like they're just Putting out fires when they'd rather be starting the rack.

And I've, I had this conversation with many people's like it my good friend, Kevin, he was like, a lot of people just want to get the CO2 in the system, let's get it in the system. But it's easy to put CO2 in the system. The thing is, is getting, doing all the prep work, which is the hard stuff. Right.

We're now. You check that, you know, the temperature probe and the pressure probe before you even start it up. So what are your thoughts on that? Have you noticed that people are trying to get the racks up too fast versus before? Because the timelines I'm seeing for the amount of electronics. People are rushing schedules. Have you noticed that?

Yeah, we are months ahead to the point where they, there's no dry goods in the store. They're not even talking about bringing product in for weeks or maybe months. And now we've got power, we've got water, so we have the opportunity to get the rack going. And yeah, it's not a not an issue here. So yeah, it's you've been really fortunate because I told those guys, you guys are way ahead because on the East coast, it's usually push, push, push and and yeah, a lot of, a lot of times I say, Hey, we're not going to sweat it.

It's we're coming, we're starting on Monday. If the rack's not running till Wednesday, it's okay. But yeah, there are guys that walk in and say, Hey, why isn't this rack running on Tuesday? Well, we're not done checking everything yet. And, and the more I talk about it, the more people buy into it and they say, Hey, I'm fine with that.

Let's just check it. Because if we start this thing, we don't really want to shut it down and start scratching our heads on this. And they're fine with that. So we do check a lot of stuff and I'm developing a pretty lengthy checklist for the control side for for Safeway and Albertsons saying, okay, we got to run through all this stuff and then you can start charging because, you know, it doesn't take that long to charge and usually they do two racks, five compressors each, and it's not that bad.

Let's just check it. Because if we start this thing, we don't really want to shut it down and start scratching our heads on this. And they're fine with that. So we do check a lot of stuff and I'm developing a pretty lengthy checklist for the control side for for Safeway and Albertsons saying, okay, we got to run through all this stuff and then you can start charging because, you know, it doesn't take that long to charge and usually they do two racks, five compressors each, and it's not that bad.

We start one rack one day and then typically the next rack the next day.

Cause you're going to learn a little bit and it's so on and so forth. But there's such a huge demand at this point to find startup technicians. And I keep telling the technicians in my community, what you got to ask for it. One thing when you get in there, you got to try really hard because there's a lot to know. Right. As you know, if you have a 200 case store, that's thousands of temperature probes and transducers, you know?

There's a lot of things to go wrong as you know, so yeah, out at at the case side, things have been pretty good. Obviously there's some things that have to get caught and fixed up front, but on the rack side it's been a little bit of this and a little bit of that. They're never perfect, but you don't really expect them to be.

There's a lot of things to go wrong as you know, so yeah, out at at the case side, things have been pretty good. Obviously there's some things that have to get caught and fixed up front, but on the rack side it's been a little bit of this and a little bit of that. They're never perfect, but you don't really expect them to be.

Yeah. You learn a little bit more like, okay, the last job, we didn't have to check that, but this job we do, and if it's wrong in one rack, it's probably wrong in the other rack and you kind of learn from that.

And what we do is we help contractors. By building customized training packages that work for their technicians, that work for their busy schedule to advance their skills in gauging them in continuing education and testing them. All these programs that we really do is really by the hands on approach, getting them to go out there and do.

And what we do is we help contractors. By building customized training packages that work for their technicians, that work for their busy schedule to advance their skills in gauging them in continuing education and testing them. All these programs that we really do is really by the hands on approach, getting them to go out there and do.

The field work. So they get tangible results and we are committed to getting you the results you're looking for. All our programs are online drip model. So I can meet with technicians or the refrigeration professional. I can coach them. I can mentor them and our team of professional really want to take your business, to the next level.

So if you're a service manager, business owner or technician, reach out, head to refrigerationmentor. com or check out in the show notes, there's a book a call link and it doesn't matter where you're at in the world, we can help develop a program that's going to help you and your business be more profitable in the commercial refrigeration and aid vac industry. Now let's get to the conversation goal.

Which is great. The same contractor over again. So you can teach them each time, but if you're coming up to say a new contractor, you haven't really worked with before they understand Danfoss a little bit, because I'm, I'm working with a lot of technicians coming to my program and say, I have not worked with Danfoss before, or I work with Danfoss before what's some of the advice that you give them.

So if you're going to meet up and you're ready to do a startup. And it's with a new contractor and the manufacturer, you would know because you know, all the manufacturers, right? What are some of the things that you set the kind of the ground rules for everyone to work on the same team?

I've been other in situations where you're kind of thrown in where in the startup is not going well. And you're brought in at the, in the middle somewhere. But yeah, the funny thing is they'll put you in charge, but in a normal startup, if we would walk in and say, okay, this is new contractor. Yeah, we have a kind of a little powwow on day one and say, okay, this is.

These are the things that we want to go through. We need to make sure that we have solid communication loops to the cases, so that we can see what's going on in the cases, and say, okay, how many pounds should we have in the cases at this point? So we can do a sweep through the cases, and check all those to see if our pressure transducers are reading.

That's one of the biggest things that we run into, is Just that there's a lot of things that have to be fixed out there. Once you get those pressure transducers reading, then you're in much better shape. And, and I tell them, Hey, if we can get 80 percent of the cases and they're ready to go, that's fine.

That's all we need. And then we'll work on that other 20%. But if, as you know, the, the case controller has a main switch in it, like most of our controllers do, and we just leave it off if the case isn't ready. And then when it's ready to bring online, we turn on the main switch and let it do its thing.

But but yeah, I tell them that, Hey, we'll just knock out as many transducers issues, issues as we can, and we'll start those cases. And then I'll prepare that custom screen I talked about back on the rack side so that when it comes time to say, okay, we've got enough charge, let's start this baby.

But but yeah, I tell them that, Hey, we'll just knock out as many transducers issues, issues as we can, and we'll start those cases. And then I'll prepare that custom screen I talked about back on the rack side so that when it comes time to say, okay, we've got enough charge, let's start this baby.

Then that's the screen everybody will be looking at, you know, what's my superheat, what are my suction pressures and how am I doing on the high side and how much is the receiver open, stuff like that. Yeah. And when it. Doesn't work at first or only partially works, then we're sharing ideas and saying, okay, that makes sense. That's why you know, this valve is keeping us from building pressure in the receiver and stuff like that. So it's been a good learning experience all around.

I think it's kind of explaining the sort of the the decentralized control that we have, because you're probably aware that, that we have a PAC controller and that PAC controller is, could sit there and run all on its own. Doesn't need the system manager, but the system manager ties everything together and it gives them a way to look at things a little more easily.

And then you've got the case controllers are doing their own thing. So often they will ask what happens if this goes down? And the answer is, well, it's going to keep going. So, so yeah, it's explaining that you, you don't need the system manager necessarily to keep things running. And that's kind of a different concept for them.

They're used to an Emerson where everything's coming out of the E2 or E3. And yeah, those are probably some of the main things, and then just explaining how we do restarts gradual restarts on the CO2 to manage the load. And then what do we do?

Because some people, on an HFC rack, you can go and just shut all the breakers on the compressors, and you know, that's it. It just stops the refrigeration. You definitely can't do that with CO2 transcritical systems. Okay, so, so what is some of this that you talk about?

Then you're going to overload the rack. So it's pretty standard now to divide the cases into groups. And when you see things like a phase loss or that nothing is running back at the rack, that everybody has to get the command to shut down. And then we have a discussion with the contractor and say, okay, which cases do you want to bring back online first?

You know, are you more concerned about fresh meat or ice cream or the walk ins or what is it? And then we divide them up into groups based on priority. So we'll bring in group one first. Once we see that there's nothing holding us back at the rack. And then at the same time, the case controllers are looking at MOP.

You know, are you more concerned about fresh meat or ice cream or the walk ins or what is it? And then we divide them up into groups based on priority. So we'll bring in group one first. Once we see that there's nothing holding us back at the rack. And then at the same time, the case controllers are looking at MOP.

And we agree on some settings for that. So that suction pressure has to be within a certain range at the rack before we can say, okay, it's time to start feeding out at the case level. And then we talk about the timing, because the timing can change from store to store. And what worked in one store may be too long in another store.

So we look at the grouping of those cases and say, okay, after four minutes, we can bring on the next group. And then make sure the RAC can handle that. And the OEMs are pretty good about saying, hey, before I leave here, we're going to test this. And everybody is there to see it happen, so that they know that, okay. If I have a problem with Phase Monitor and it shuts me down, it's going to take me 20 minutes to get back up and running again.

Just like Dave said, I think the, this is where. Some technicians are like worried about it. Like, how do I, if it shuts down, will it start back up? This is all something that is pre programmed in there. Before you release this to the customer, it should be tested. And sometimes it is, and some of it is a lot. I know I talked to a lot of technicians in my program and they're, they're saying like Trevor, I'm worried about if the store goes down. I won't know how to start it back up.

And what's your PC, your condensing pressure so that we can get a picture of the whole system and see, okay, is there something electrical that's holding us out or is it, are we just in a delay before the PAC controller says, okay, everything is good. We're going to start up starting with the variable speed drive.

And what's your PC, your condensing pressure so that we can get a picture of the whole system and see, okay, is there something electrical that's holding us out or is it, are we just in a delay before the PAC controller says, okay, everything is good. We're going to start up starting with the variable speed drive.

Through the startup with the OEMs as well as your startup team. But I keep telling them when you leave this program, you get your first CO2 store. You and your team should go out and actually do a power outage or do a shutdown. So you know what it looks like. It feels like because like you said, you guys want that to happen before you leave. You know, so they know what to expect because if it doesn't come back online, then there's some things that they can ask you at that point.

It's a four wire stepper valve driven by a driver, which gets its signal from the system manager that says. Okay. At this point, I want you to open this much. It's sort of a safety on how to manage the load coming back. And if that valve doesn't open all the way, for some reason, we talk about what possibilities they have to maybe override it temporarily or put a valve driver on it, those sorts of things.

It's a four wire stepper valve driven by a driver, which gets its signal from the system manager that says. Okay. At this point, I want you to open this much. It's sort of a safety on how to manage the load coming back. And if that valve doesn't open all the way, for some reason, we talk about what possibilities they have to maybe override it temporarily or put a valve driver on it, those sorts of things.

So yeah, I, yeah, I often ask the startup guys, how do you hand this over to the maintenance guys? And there's sometimes there's a shrug and they're like, well. We have a talk about it and then that they're on their own, but you know, as you know, the startup guys are onto the next one usually at that point.

And but yeah, they will kind of hand my phone number down the line if they happen to which is good and bad at the same time. But but my feeling is if you do the startup well, that there's less problems down the road. I

If the startup was done right. And it was thorough and they, you know what I mean? They, even the finest detailed stuff does come up, but it's all about that initial startup. And if that is rock solid, you have way less issues. When it starts to get cold out, like here, we're down, we're 26 Fahrenheit right now, you know, minus a couple Celsius and it gets down to minus 17 Celsius, so.

Minus 20 there a few days or last week. Right. So really cold. And in my, my community group, we had a bunch of guys that were doing CO2. One guy was out of was it Michigan? I can't remember where, what place he said, but he's like, it got super cold. My head pressure dropped all the way down to 570 or, you know what I mean?

I'm like, what? They put down that low and like your flash tank, what's that supposed to be? Well, we're supposed to be running it at five 20, I think it was PSI, but it was running at like four 50 and then I'm like, what is your suction? Well, we're trying to do plus 20, which is four Oh seven. You know what I mean?

I'm like, what? They put down that low and like your flash tank, what's that supposed to be? Well, we're supposed to be running it at five 20, I think it was PSI, but it was running at like four 50 and then I'm like, what is your suction? Well, we're trying to do plus 20, which is four Oh seven. You know what I mean?

I'm like way too low. So why is it going that low? You know what I mean? What caused it? What was your minimum gas cooler set point on your ISTM valve or, you know So it's like understanding that and because if that was all programmed in first, you know, if that was programmed in, that should stop at that specific minimum gas cooler temperature outside and then, but it was maybe missed and he's diving into it now because this was just last week.

Yeah. Yeah. I feel for the guys that are starting up some of the smaller stores that are coming online where the CO2 rack is plopped on the roof and it's, 15 degrees outside Fahrenheit, and they're trying to start the rack. So you're fighting the elements when you're trying to get this rack up and running. Fortunately, there's a lot of similarity from job to job, but still, that's brutal. But one of the things I run into is that you can't start the whole system when everyone's there typically.

So we have chat about that because Heat Reclaim typically comes online much later. And we make sure that we have remote communication to the site and that okay, here's my plan for helping you start heat reclaim that when you get to that point and they've got it all ready to go, then let's walk through it so that I understand how they want it to work.

You understand we kind of start it gradually to make sure the rack is going to be able to handle it and then kind of see how it goes, but you understand how much heat is potentially there, so you know, you can really take advantage of it so, but it's never ready on day one. That's just the way it goes.

Yeah, and I definitely agree with that. I think there's a lot, lot to do. Once we talked about earlier is the sequence of operation. I feel as I do my trainings and training more people is that a lot of technicians don't understand the sequence of our operation. And I'll be honest when I was in the field.

For 10, 8, 10 years, super, I didn't understand that. See, I understand some of it, or I understand like a piece of the sequence of operation, but not the full end to end operation. And there's just way more sequence of operation in a CO2 system. I feel versus an HFC or a standard rack.

Is when things are not going well and they're kind of going sideways on, yeah, the guys will kind of look at each other and say, okay, let's start at the basics. And a lot of times that's where the problem lies is that, yeah, we really thought that valve was working the way it's supposed to, but it's actually wired wrong.

Is when things are not going well and they're kind of going sideways on, yeah, the guys will kind of look at each other and say, okay, let's start at the basics. And a lot of times that's where the problem lies is that, yeah, we really thought that valve was working the way it's supposed to, but it's actually wired wrong. And that explains all these other things. So but yeah, a lot of that, that happens not only in CO2, but. Everything, it seems like,

Flash tank was crazy volatile. And I'm like, okay what did you do? Like, did you go check the drop leg sensor? And they were like. Yeah. We went up there and it was a CPC sensor. And I'm like, what do you mean? It was a CPC. Yeah. It was the green wire from, from from Emerson or, or, or, and you know, like what controller was that? And that was I think it was a 72. No, it was an EKC That's what it was.

But you need a PT 1000 temperature probe, not an NTC probe. And he was like, they didn't know that. And that was the major issue, you know what I mean? So, and it can happen. I don't blame the technician because you just don't know because I just, I always grab that sensor and I use that for everything. Right, right, right.

What if that sensor goes bad? Well, the PAC controller allows you to put two sensors in there. And if one goes bad, it'll know how to switch to the other one and alarm out if that temperature difference is too large. But the last job, it was coming out of a gas cooler, probably in the right place, but it was insulated with black tape.

And they're like, hey, it's only 40 degrees outside. Why is it reading 75? I said, well, you can start the rack and it'll run, but it's not right. So we talked about how to how to insulate that correctly and reflect some of that sunlight off of there. So so yeah, those are, like you said, the basic things that you have to cover.

And they're like, hey, it's only 40 degrees outside. Why is it reading 75? I said, well, you can start the rack and it'll run, but it's not right. So we talked about how to how to insulate that correctly and reflect some of that sunlight off of there. So so yeah, those are, like you said, the basic things that you have to cover.

Or would you put it on where it's teed at, at the outlet there? What is your opinion? Cause everyone has their own. I put it here right by the gas cooler within six to 12 inches. You know, 150 milliliters, 30 centimeters, or I put it right at the, right at the level where the two of them come together.

Yeah. Chris Brown could probably give you an even better answer, but the, the, the widely accepted answer is at that common point. If you're only going to put one sensor in one sensor, just use the common point. Yeah. Yeah, if you're going to use two sensors, then I would say you would probably want to put one on the year round side and one on the common point, because really there should be very little difference there.

I'd love to see that trend graph and I'm sure you may even have it, Dave, but I want to see that because I have people in Australia say, no, it has to be at the common or, and the other people say, no, it has to be six inches from the gas cooler. So if anyone's listening, that has that data, please send it because I'd love to know, but I'd love to see, cause everyone has their own preference.

It works better here. No, it works better. Right. Right. Yeah. And what we do know, it needs to be really insulated. It can't be, you know what I mean? It has to be strapped properly at the right location, you know, four and six or eight and a 10, depending on the size of the pipe, but we don't want it at the bottom.

Right, right. Yeah. And guys are getting better at insulating them and then putting kind of a white plastic cover over those to keep that sun influence out of the picture. But. Yeah, I think this will be debated for a while until we come up with the correct wording for the science on why it needs to be as close as possible and and then prove it. Yeah,

that you get a better operation because some people are even wanting to put them down in the compressor room and we'll swear that it works better. So, yeah,

Well, yeah, this is why it's because you guys aren't new to CO2. This is the thing is like, you guys have been doing CO2 for 25 years, 20 years. Like it's not new. But the way we are evolving is new in these new ways of doing CO2 is, is evolving, which is cool. And what you must love, it's really coming back.

To the controller side, like I keep talking to the technicians in my programs, like we got to get you in more controller. So we're doing more controller training and we're teaching like even last night in my supermarket course, we were going through how to set up a Dan Foss drive to a compressor. You know what I mean?

Because that's still something new, even though we've been doing it for two, three decades on compressors. You know, but yeah, we're going through it. Now we went through the program was okay. What are those parameters that you need? How do you wire it up properly? Because a lot of them, as you know, are in bypass out there.

Not on CQ systems, but on most of the systems that have a drive on it, it's just in bypass. Oh, there's something wrong with, they put it in bypass and then nobody comes back. And there are like, even the guy that I had last night, he was like, I was afraid of it until we talked about it, Trevor. Now I want to learn more about it.

I'm going to try to embrace it. It's hard. Cause I'd never did it before, but I want to learn. And then when you want to learn, you want to grow. I'd love to hear about some of those stories on the drive set up, because I'm sure you've heard tons of these stories. What is the big precedent of a technician having a drive on a compressor, on a rack?

I'm going to try to embrace it. It's hard. Cause I'd never did it before, but I want to learn. And then when you want to learn, you want to grow. I'd love to hear about some of those stories on the drive set up, because I'm sure you've heard tons of these stories. What is the big precedent of a technician having a drive on a compressor, on a rack? What do you, what do you feel that it is?

So people went away from them for quite a while. Now with the emergence of CO2, people see the value in those. And fortunately, the Danfoss drive is so widely known and accepted that the OEMs are Really pretty familiar with those and they take ownership of it. They set it up, they program it. They know how to copy to the keypad, all those good things.

So yeah from what I've seen for the most part, if there's a drive issue, it has something to do with a loose connection in at the lugs somewhere. Maybe a control wiring problem that has to get sorted out, but. By and large, they don't seem to give us problems. And if there is a problem, then they call our drives division out in Chicago and get some support to figure out what's going on with it.

So yeah from what I've seen for the most part, if there's a drive issue, it has something to do with a loose connection in at the lugs somewhere. Maybe a control wiring problem that has to get sorted out, but. By and large, they don't seem to give us problems. And if there is a problem, then they call our drives division out in Chicago and get some support to figure out what's going on with it.

But yeah, the drive doesn't seem to be a, a huge issue at this point. From what I've seen it's just a matter of understanding the value.

You make sure you do not touch any of those wires, you know, drive, you shut them down and wait 10 minutes. It says right there in the first, you know what I mean? Five, 10, yeah. Yeah. Capacitor. So be safe on that. But, but we're going to see more and more of that on CO2 systems. And I think everyone that I've been to, there's a drive on it. You know what I mean? On, on the raft. That's very, very important.

You know what I mean? On, on the raft. That's very, very important. Dave: So let's, some of these if I, if I can, the some of the maintenance managers, construction managers, the guys that are saying, let's put a drive out there, they're getting wise to some of the tricks. So they're alarming out if the drive goes into bypass and if the drive goes offline, because depending on, you know, how you tie it in, the drive can talk to the system manager.

And that allows you to alarm if it goes offline. So if it goes offline for an hour or two, that's okay. Cause it's probably maintenance, but if it's been offline for a week, now there's some, some questions are going to be raised because that, that really defeats the purpose of having it. You can run the system with, with a dry and bypass because there's thousands of them probably out there right now.

But the thing is, is that. With the drive or with some capacity control that just makes the system run and per so much better. And it's so important in CO2 that the rack is stable. So your high pressure valve stable. So your flash gas bypass is stable and all your EEVs are stable. And when you have all those four things working in conjunction, you're going to have a good running transcritical CO2 system.

But the thing is, is that. With the drive or with some capacity control that just makes the system run and per so much better. And it's so important in CO2 that the rack is stable. So your high pressure valve stable. So your flash gas bypass is stable and all your EEVs are stable. And when you have all those four things working in conjunction, you're going to have a good running transcritical CO2 system.

And the rest is just maintenance on top of that. Just the standard maintenance, like you're supposed to do in your standard stores at this point, you know the, the big thing I've, I've seen that as well, like I work with a lot of my my, the technicians that I work with is that learning the fine tuning that case control or after, cause you do the startup, but you got to come back in like a few weeks later or so be someone monitoring and then do the final adjustments because that case controller, that case in the bakery with these set points.

Well, maybe all of a sudden they move that, that, that where that oven is, you know what I mean, or it's a lot hotter than was expected or anticipated, or where these Delhi open cases now have diffusers that are shooting down and you're getting a little more infiltration or broken air than you can, but you can't do anything about it. It's not like you all of a sudden you're going up and putting. Cut out the diffuser, you know, so you got to worry, it's not.

Right, right. Yep. I think you'd like anything else. You develop a punch list based on the, the biggest issue you see and kind of work from there and look at how you know, obviously graphing and trending is, is super important there. You get your baseline and then you say, okay, I'm going to adjust this this P setting or this I setting a little bit and see how my valve reacts. And then But yeah, one thing affects the other in a big way.

D. I need to know P and I. D. and how to adjust and how to train it. But you guys have been developing this stuff. For decades, like these controllers, you've been working on the P and IDs, all the big control manufacturers. So people don't have to go in and really adjust them. That baseline is usually, usually good.

You know what I mean? But there is some fine tuning. You want to talk about what that really means and when someone should look at adjusting the P or the I or the D, depending on the controller. And what those really mean.

You know what I mean? But there is some fine tuning. You want to talk about what that really means and when someone should look at adjusting the P or the I or the D, depending on the controller. And what those really mean. Dave: Yeah. Yeah. So a lot of times we will run into people that are used to Emerson because they do a lot of PID stuff.

Yeah. Dan Foss breaks it down and a lot of times they'll drop out the D part and they'll just do the P or the P and the I. Typically the P and the I is what you see the most. Yeah. But For us, if you see a setting called Kp, capital K, lowercase p, that's the p setting in our controller, and then Tn is the i setting, so capital T, lowercase n is the i setting, and the Kp setting will adjust the p parameter A little bit at a time.

And the golden rule always seems to be that you make a small adjustment and then you wait and you don't change both of them at the same time and then kind of stand back and see what happens. But you typically will adjust the the KP setting first, just a little bit. And then if you're not quite happy with the results, you can change the TN setting.

And the golden rule always seems to be that you make a small adjustment and then you wait and you don't change both of them at the same time and then kind of stand back and see what happens. But you typically will adjust the the KP setting first, just a little bit. And then if you're not quite happy with the results, you can change the TN setting.

And in general. It seems to be that you're trying to slow things down, which is counterintuitive because you, you look at it and see it kind of hunting around and say, if only I could get it to react quicker, I'd be fine. But talking to guys like Mark Sever, who over in Europe, it's a Dan Foss guy, really smart with CO2 and controls and, and he said, in general, you want to slow it down and that's generally where you start, but you got to have a baseline and remember those numbers you started with.

Because you might have to walk them back. And the, the biggest thing I think is that we don't give ourselves time to work on this stuff. Yeah. I like, I like, I like what you said first there. Sorry, Dave, that you don't change it. And then second later, you change the other one and you change two of them at the same time, it's like process of elimination, you move it up or down.

So for an example, if we change the KP, so that's the proportional, if I increase it, does it go from zero? I can't remember, honestly, zero to 100 or what's the range? So for an example, if we change the KP, so that's the proportional, if I increase it, does it go from zero? I can't remember, honestly, zero to 100 or what's the range?

0 to a 2. 5, you're telling it to respond a little quicker. based on how far you are from your target. So as you go up in number, you're going to tell it to react a little quicker. And then on the TN side, you're working with a window of time and how you want it to look at those samples. So a wider window might help you.

A wider window of time, meaning you're going up in the number of seconds that may help you rather than take a shorter time window for this controller to figure out what it needs to do. But, but it's it is really cool when you find one that's not behaving itself and you find the right combination.

A wider window of time, meaning you're going up in the number of seconds that may help you rather than take a shorter time window for this controller to figure out what it needs to do. But, but it's it is really cool when you find one that's not behaving itself and you find the right combination.

The PI setting is kind of magical. And, and once again, this is something that takes time, work with someone who knows how to use these. And it's not something you just keep changing it. Sometimes you got to let it go for a few days, you know, you just watch it. It's not like you change it in 10 minutes later.

And there's there's ones that you definitely want to capture in history because that's going to tell the tale when you come back the next day and say, okay, how am I doing on these changes I just made? So it's easy. It's an easy things to forget. Is to go into history and think about all these parameters that I want to have, start logging. And it'll help you sort it out after the fact.

Am I, is my valve even opening up properly? Like did someone put a maximum opening percentage of 50 in there and it's not fully opening or closing? Like there's all these other, you don't go change that until, you know, all the other parameters are where you want them. So there's a lot to it. Yeah.

Yeah. There is. Once guys do a couple of jobs, then they kind of start to get the hang of it and realize that, okay, there seems like there's a lot here, but it's manageable. It's just that the numbers scare them sometimes because like you said, you've got so much to do and they want to get the rack running and all this, but yeah, you have to back it up a little bit and then just go through there.

And sometimes we'll we'll get a group of. Three people, if we have to, to go through all the case settings and say, we think these are like 90%, but Let's kind of make sure, and if we see we need to adjust something, we agree on a new setting and we go with it. So and then we try to get better on the next one so that those settings are already there waiting for us.

Well, there are guys that are not the laptop is not part of their everyday. Yeah. So and that's okay. Because the laptop is, it should be something that they have now and you know, laptops have come a long way in the last 30 years, so they don't have to be expensive, but once you get the laptop, get the cable, get the software that lets you plug right into the PAC controller and you can log in and you can look around and familiarize yourself with the menus and you aren't going to break anything.

You're just creating some familiarity. And then what I show the guys is here's how you use the wifi to connect to the system manager. Here's how you back up the file on the PAC controller because it can get forgotten. But use the laptop to back up the file on the PAC controller because bad things can happen.

Not often, not often. But when the water's dripping out of the pack controller, you knew you're going to have to change it. So you're going to want that file to put it back in there because all those PI settings need to be put back just the way it was. And the backup file is your best friend at that point.

Not often, not often. But when the water's dripping out of the pack controller, you knew you're going to have to change it. So you're going to want that file to put it back in there because all those PI settings need to be put back just the way it was. And the backup file is your best friend at that point.

So we're not asking them to be. Laptop experts or anything like that. We just want them to be able to back up files, familiarize themselves with the menus before they are sweating because the rack's not running and it just helps them down the road.

Why would I use a cool selector? But when they start getting into it, that's where all the manuals are. You know what I mean? You might not use it every day. Well, I can do it on my phone. Well, for me, I do a lot of work on my phone. I do my whole business on my phone. But I need a computer to look at some small print.

Why would I use a cool selector? But when they start getting into it, that's where all the manuals are. You know what I mean? You might not use it every day. Well, I can do it on my phone. Well, for me, I do a lot of work on my phone. I do my whole business on my phone. But I need a computer to look at some small print. Sometimes look at wiring diagrams. It's a lot bigger. You can see it right here. And I did I did a CO2 experts with Damon Reed from pro refrigeration. They use a lot of Dan Foss and we were going through how you use the service tool, how he uses the service tool and the value as a technician where you can see the whole thing and make it just to make it easier, you know, we're not trying to make it more complicated.

You guys are trying to make it easier for the technician. Can it be frustrating learning something new 100 percent I'm used to gauges they're analog and I'm used to these old temperature bro. All digital stuff is came a long way to help us out. Yeah.

Yeah, that's totally true. But it's but it helps them in the long run and you know, these days. Guys have to email from the job site and all that sort of thing anyway, and something they didn't do 10 years ago. that's totally true. But it's but it helps them in the long run and you know, these days. Guys have to email from the job site and all that sort of thing anyway, and something they didn't do 10 years ago.

Tell me a little bit about controller talk where you and Chris are going with it. 'cause I've learned a lot about Danfoss from, from you and Chris on, on that. So okay. Let us know a little bit about it.

And like a couple of naive kids, we said, Oh, I guess so. And knew nothing about it. Marketing does all the heavy lifting, like the recording and the cleaning up and all that stuff. And we just take ideas from calls that we've had or the emails that we get over and over. But it's been a, a really good experience and we kind of decided that we were going to have our own little format and have fun with it.

And like a couple of naive kids, we said, Oh, I guess so. And knew nothing about it. Marketing does all the heavy lifting, like the recording and the cleaning up and all that stuff. And we just take ideas from calls that we've had or the emails that we get over and over. But it's been a, a really good experience and we kind of decided that we were going to have our own little format and have fun with it.

And and I'm always trying to come up with these ridiculous questions for Chris and and and most of these things I don't even know myself, but I'm willing to ask him and see if he can embarrass himself. But but it's been a good experience and we try to keep them down to like 20, 30 minutes so that it's manageable.

And maybe a guy can listen to one from job to job. And I talked to more of these guys that say, Hey, I can't be on my phone while I'm in the van, but I can listen to a podcast. And so that gives them an opportunity to maybe take some dead time or downtime and, and, and do something with it, but we try to make sure that we're educating people. Like I said, we have fun with it and keep it relatively short. And then what's happening now is that listeners are feeding me ideas.

Like I said, we have fun with it and keep it relatively short. And then what's happening now is that listeners are feeding me ideas. Yeah, so they're telling me these are the things that I would like you to talk about and it's been a good experience. So we usually try to release from essentially September to April every two weeks and then take the summer off because you know what summers are like

He wants to help. He wouldn't have been doing technical support for 30 years to help people because he didn't care. He does care. And he likes to see those successes when, when they happen. Dave, thank you so much for taking the time to talk with me at the Refrigeration Mentor Podcast. And I look forward to some more conversations with you because this has been really awesome.

He wants to help. He wouldn't have been doing technical support for 30 years to help people because he didn't care. He does care. And he likes to see those successes when, when they happen. Dave, thank you so much for taking the time to talk with me at the Refrigeration Mentor Podcast. And I look forward to some more conversations with you because this has been really awesome.

Like there wasn't much and mostly I started with an E2 and then micro thermal started to take, take over. But then I started to see more and more Dan Foss. And now I talk with lots of people about Dan Foss, because I deal with a lot of people in Europe and Dan Foss is a dominant player over there. And over time is the more technicians come in.

They asked me more Danfoss customer, which is great because I have to go look at it. I feel like I'm getting better and better and better at Danfoss. Thank you for the invite. I appreciate that. But thank you for coming and sharing some knowledge with with the listeners and go and check controller talk. Dave, thank you so much.