Episode Transcript
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Welcome to the Refrigeration Mentor Podcast. I'm your host, Trevor Matthews. And once again, thank you so much for taking the time to listen to us. I know you're driving around. Heading to another site, we're gonna be diving into compressors today.
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So I get better. And this is how I'm bringing all of these experts from around the world to learn and grow, to help you as a technician out there in the field. So you get better, a little bit better tomorrow than we are today. And this is what it's all about, uplifting the industry. Horace Andy, welcome to the Refrigeration Minter podcast.
oh, I grew up in downtown Atlanta and my father had a relatively large refrigeration service company. So when I graduated from high school I went to DeKalb Tech, graduated there doing refrigeration, air conditioning. Worked in, well, my father's company for about 12 years from, from 73 all the way up to 1985 and had a little brother that's coming behind me six years behind me that's also doing refrigeration service, company service, and he's got my father's company to this day.
move the company. So we called David and I, which was my business partner, and sold us the company. So we bought a one in 1998 and grew that company up to be a very large
When you remanufacture, when we do total disassembly and every compressor that you get off the shelf when we finish it up, because the total remanufacturing there every one of 'em is exactly the same. It doesn't matter whether you get this compressor off the off the shelf or this compressor off the shelf, they're all gonna be with the same.
total disassembly where one of, where one of 'em would not be co disassembled.
And so uh, we continue a lot of that today at our factories across the, the, the country here in the us and our distribution ca locations around the world. And so it has become a, a, a nice, fun endeavor to ensure that we've got semi hermetics on the shelf. We've got screws on the shelf, a number of products that are out there.
Yeah. Yeah. I had a, a community meetup with the refrigeration in their community. And I had a guy, I think it was Belize or Trinidad, one of my buddies, I can't remember which one it was, but they were like, yeah. It's hard to get components.
Well, usually it's the compressor's doing something that, that's a little out of the ordinary. You know, maybe it's pulling too many amps or maybe you have a hot head.
Sooner or later they were going to gonna get into doing some refrigeration work and they would always put the wrong size expansion valve on. And whereas one horsepower per ton, you know, when you're doing a a a walk-in cooler it, you know, if it's, for instance, if you have a three horsepower compress compressor, it'd be a three ton air condition compressor.
Absolutely. Okay, well, so let's dive into what's the, let's just jump to the next slide. So if you're listening to this onto the podcast jump into the YouTube channel and you can wa go through the slides. But we'll dive into the first one would be super eat. What does it really mean
Yeah. And, and I talk with a lot of technicians in our training programs. Like I got a compressor course and I talk with them. I'm like, it doesn't, if you think about visually, it doesn't always, it's not always a actual, a liquid that's going in there. It could look be like wet gas and this, I learned this from people.
It's not only that evaporator soup read and, and you know, setting up the, you gotta set up the TXV to that evaporator. So if it's a four degrees soup readed or, or six or 10 degrees soup readed Fahrenheit or 5K you need to set the evaporator super heat, but you have to check that compressor super heat or that system super heat like we're talking about here.
Go back then, and then you can check your amp draw and make sure you're run running. Correct amp draw on it, make sure your oil's at the right level. And then sometimes you can actually put the thing on a freezer and defrost.
'cause we had loads changing all the time. So you, your soup eat could go up to 10 degrees Fahrenheit and then it goes all the way down to say four degrees Fahrenheit. Just remember, you don't average that out. Your lowest would be that four degrees or that 2K. Because that'll catch you. 'cause it happened to me.
With the low tap applications, you may see that. Yeah. Two also we've had, I've had where they change the compressor out and the system has a small leak in it and they'll change the compressor out and then it'll leak down and about a week or two or a month later, you know, it'll flood back, ice the compressor back, flood back, tear the compressor up again.
And this industrial system, four inch, five inch pipes going through massive. So if they can do it on your commercial system, you can definitely pull the proper evacuation. Let's talk about that. What are the things that you would see if you don't have a properly evacuated system in a compressor?
Pulling the deep back is so, so important because if you don't, if you get moisture in the system and your liquid line filter dryer doesn't pull it all out, what can happen?
They got loss of lubrication, liquid slugging, and electrical failures. And I like what you bring up before when you're checking your superheat or you're starting up your system. You gotta check what your amps are and you gotta make sure that amps are in range. What are some of the tips you give technicians when they're looking at that?
You know, when I do seminars, sometimes I feel like I, the people are gonna say, oh lord, it's don't talk about super heat. But, you know, 90% of all the compressors fail because something in the system causes that compressor to fail.
Zero supr, whether it be on a startup or whether it be just where the coal ice is up. It plugs back in there and thins the oil out where it can't lubricate there and you don't have an oil safety switch on it, or one that's working, but, but 60% of them fail because 60 or 70% because liquid enters the compressor.
Like we know over 80% is mechanical failures, you know, and that's due to liquid coming back or overheat. And really all of it comes down to the end of the day is lubrication, right? Mo, all of those mechanical issues is all come back to lubrication. 'cause you go overheat. You're breaking down the oil, you got liquid coming back, it's washing out the oil.
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But when it's off and it's off cycle, then that's when your liquid's gonna come back all at once. You know, and if, if, if the power shuts off and you have 10 or 15 pounds of refrigerant hanging out in the evaporator. And it starts, you know, moving toward the the compressor there. It's gonna get it on startup.
'cause I've opened up so many compressors and just taking off the head will tell you probably 80% to 90% of the story. Sometimes you gotta dive in deeper and it's really hard to figure out problems on those tricky ones. But for a slug, a lot of times you can pull that head off and you can tell it took a slug.
Valve reads mainly of long gaskets and all, but if it, if it's got lack of lubrication to it, we can always tell by the scuffing of the pistons and the the guarding on the rods and in the bearings, we can always tell there this lack, lack of lubrication there, where that would be, again, a slow leak a flood back instead of a slug there on it.
If one is way hotter, just like aura said there, that is a problem. I, I think in the Bitzer manual they say 30 degrees differential. You definitely want to check that. And with the tools today, they have, compared to adoption, I had, you got thermal imaging guns, you can just put 'em on your phone.
But if you think about it, it throws the balance off of the compressor because the gas is seesawing back and forth in that valve where it's supposed to be. And that's what causes your heat on there. But yeah, it'll cause vibration. And if you're changing the compressor out on a rack, and I'm sure Trevor, you've probably touched on this, but it'll have a little plate in there with a, in your discharge line, it's got a bunch of little holes in it, and that's for vibration purposes also.
There's a reason why it's in there.
Do it in a star, star rotation, just like a tire. I tell people. And that makes a sense. Are you seeing lots of compressors coming back and it, could it be just the valve plate replacement?
Let's talk a little bit about electrical issues and electrical failures, because I think this is where a lot of technicians would like to feel a bit more confident. 'cause if you take off a head and you see a broken piston, you know, or, or if you pull it off and it's all burnt, you know, and the compressor's just a, a full winding burn you kind of get a good idea.
Well contactors have a lifespan. And if you don't know when that contact's been changed especially if you're changing the compressor, go ahead and, you know, the compressor's the most expensive part of the system and, and the contact's one of the cheapest parts of the system expense wise.
You want like a nut on the bottom, and then you want your wire, and then you want a nut on top to make sure it's all metal to metal on your electrical connections. Part I tell you also though when you come up on a compressor and it's all burnt. It really doesn't mean that you have an electrical problem.
You'll be, you'll be where part line start, you can run up on something that has two contactors that brings the compressor on. And if you're changing out that compressor, you need to mark your terminals or and your contacts if you change them, mark every wire. Exactly. And put every wire back on. Exactly.
As well as dual dual voltage motors 2, 2 30 or, yes. Like you gotta, you gotta check what you're, how you're wiring that up, because that's so important. If you wire it up for a two 30 volt motor, and then you put it in a four, or sorry, four 60 motor, you wire up to two 30 and you hit it with four 60, that compressor's in trouble.
And I did it on my church, you know, three months ago. But if you miss, if you run a, a compressor a scroll compressor backwards, it's gonna sound like it's gonna, if you get one thing, if you run it backwards, it's just gonna sound like it's going to blow up. you know, and, and there's nothing wrong with a compressor.
Yeah. I think a big thing is I've seen a lot of for electrical one where people will go and they'll go across the winding and then it'll be like, oh, it's a, it's a a dead, it's a shorted compressor.
'cause they, like I said, they will, they'll short out and run a lightning trail almost when you turn it on, it'll sound like explosions. So we want that to happen.
So, but yeah, O overheating is, is, is a, is a, is a big problem, but maintenance. Everything that we talk about, a good preventive maintenance system will help you, you know and make your own. There's two things you need to make maybe make up your own startup sheet. When you have a compressor failure, it'll make you check things that you normally would forget or you wouldn't check.
And if your compressor is not burnt on a semi-hermetic compressor, you know, close your suction and discharge valves, front seat, both of those.
Oh, check your contact or change the contactor. Again, like we talk about contactors, change the dryer. You know, it, it is very inexpensive there, although we change the dryer on it. And Trevor, I don't know how you feel about it, but sometimes they get in trouble putting a, a suction on filter wrong, you know, and that's good after a burn.
Yeah. Yeah. I don't re myself, I don't, I never use acid away. I always put a suction line, filter dryer and then removed it. If the pressure differential gets over what the manufacturers recommend because they say it right in there. You go into sporin, you'll go into the COBAL ones and they'll say like, depending if it's a permanent installation or just a temporary installation, they'll tell you the times on when to pull it out after 24, 48, 72 hours.
Yeah. Pressure drop, like you talked about though, it'll also make the compressor run hot too because you're running a, a lower suction, like, like not getting enough gas across it to, to help cool your winds or cool your compressor. And so,
Have you ever done that? Recommended that for your customers and checked actual dual lab analysis? And what are you looking for in that oil?
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Correct. You know what I mean? This is the all the different gases that non-con condensable that potentially is in that system. So this is why super important, especially on larger systems. To send it out to a lab. Awesome, awesome. So what are a few more things that you could put on that checklist for them when they're building the checklist?
Also, that defrost termination switch does not allow it to go on. Defrost with the box is a certain temperature. So I have seen it where they would jump that out and it would absolutely melt the door gaskets right off the, the glass doors because it goes into defrost when the box is 80 or 90 degrees.
That's something going on with your defrost or your fan termination. You gotta have a drip time after the defrost. So you go into the E two or the Danfoss or Microthermal and you set up your drip time. Follow manufacturer's instruction, it's all in there. It could be five minutes, it could be 10. It all depends.
It's visual. You're touching stuff, you're listening to this stuff. You're getting your volts, your amps. It's all about facts. When you have a, that, all those numbers, even if you're not really that great at figuring out what's going on, if you give it to an expert and they see these numbers and they're the right numbers, they can usually tell you what is going on with that system.
yeah. While, while I'm talking about valve plate two I always hit in my seminars is that if you buy a Copeland valve plate kit a Copeland compressor valve plate kit, whether it comes from CNP or whatever, you're gonna get several what we call bowel plate gaskets.
Yeah, exactly. That's a good one. And one of their guides is good. It's the 40 60 parallel rack one, and it explains all that, like the, the boar size, why they put that in there, the thickness.
Four 10 a. A semi herbal compressor. Most of 'em are not built. There's only just a few that's ever been built that would run four ten eight, but never put four 10 a in any, any of our compressors that we remanufactured here at at at CMP. I've never heard of any, anyone put four 10 a in it so people, well, they got it in my truck now, you know what I'm saying is okay, I'm a little short of refrigerant and all I got in my truck's four 10 a, it takes, you know, 4 0 4 or whatever else.
But if you touch it and it burns your fingers right off, it's probably running too hot. You know, it's probably run too high.
Good. That's one of my five, that's one of the five ways I I, I talk about charging the system up. You know, the other one would be the gut feeling. In other words, when you're charging the system up and you close your suction your valve on your, on your gauges, on your suction valve, and your suction pressure is either maybe 10 pounds lower than you wanted it to be or thought it would be, or maybe 10 pounds higher than it should be, then that's your gut telling you there's something wrong with the system.
Oh my God, this is loud. They walk in. It's like that compressor three is knocking. There's a, there's something wrong with compressor three or compressor four. And most people are like, I don't know, I don't hear anything. It just sounds like a loud motor. So you'll get that over time as, as you work more on these systems.
And we send out technical tips and tricks and things like that all year long for folks to be able to learn and grow with us. And that's what we, we really encourage and we really appreciate the the, the customers that do. Read our warranty reports and actually call us and try to get more additional education and, and information on how to improve and how to get better.
And, and you guys out there let your helpers be hand on. The reason I say that is because I, like I said, I had a little brother six years coming behind me that in, in there, and I would have 'em. Fixed and done before he and never let him do anything. You know, of course he did go to school to take it, but you know, when my, my thing was put 'em in and get gone.
Piping, compressor, release service. Just try to be the best at whatever you're doing and you'll see yourself start to advance a lot faster than everybody else because everybody else is just doing what they're told to do or just going as status quo. But those of you that put that hard work in now, it always pays off later.
Tell us how we did, how do we make this better for you as a technician if you want to grow and learn more. Once again, I wanna thank you guys so much for taking the time, and as always, let's get a conversation going. Thank you. Thank you, Trevor.