August 4, 2025 • 36 mins
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In this episode, we go deep into detail about understanding the ins and outs of compressors. We cover everything from components, to common mistakes refrigeration technicians make when it comes to compressors, to practical tips for troubleshooting and finding the root cause of compressor issues. Understanding compressors is critical to helping technicians with efficiency and time management on service calls.
In this episode, we discuss:
-Compressor components
-Advanced compressor troubleshooting
-Avoiding parts changing mentality
-Finding the root cause of compressor issues
-Understanding compressor proof failures
-Taking notes on jobs
-Efficient compressor replacement strategies
-Checking compressor specifications before installation
-Learning from manufacturer manuals
Helpful Links & Resources:
Episode 115: Understanding Compressors: What You Need To Know
Episode 188. Compressor Secrets (I Wish I Knew When I Started My Refrigeration Career)
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker (00:00):
What's up everyone? Welcome to the Refrigeration Mentor Podcast. I'm really pumped up once again that you're here hanging out with me. Listen to me just for a little bit. Hopefully you're taking things away. This is what it's about. Learning a few things and going, applying it in the field. That is the biggest thing that if anything you take away is actually what we talk about here, is trying to go and apply it in the.
(00:01):
It is a hot summer. The biggest thing is, is that people are starting to realize that we need training consistently, yearly. There's companies I'm working with and technicians that I'm working with, like Trevor, I know it's busy, but I gotta schedule some time for training. You know, there are times when they're working 60, 70 hours a week and they're still showing up for the training.
And this was really good. Refrigeration technicians, good ones will admit that they make mistakes and often we make mistakes. And it could be from a little mistake to a big mistake. And the biggest thing is that one of the hardest things is, is owning up to your mistakes. And it doesn't matter if you're refrigeration or not, but a lot of the people that come to the training program talk about it and how they overcome some of their mistakes.
I don't know if I went and did something or not, but I came back and the pump was burning hot and it wouldn't pump. It wasn't pumping. I filled it up with oil, turned it back on, dead. It would not pump. So what happened? I just burnt out the pump because there was no oil in it. And that there, even that there, that's that's an expensive component.
One example, I, I do, when I talk to a lot of. Managers and business owners, or even just lead technicians is a mistake that younger techs may is calling multiple technicians on for the same problem. It's okay to call different technicians about different problems, but call 'em four or five technicians in one hour on the same problem.
It doesn't mean that you're not gonna get to the same result, one may take longer than the other. So that was one of the things that you know, really is key to understanding is talk with one. Technician, and this here is another learning step for me. That was a learning step. 'cause I did call a few different technicians.
So I talk about compressors a lot. I was talking to my good friend Ernie today. He is now the Lee, a technical manager of. For, for Bach. Now he's a, he is a control expert. Danfoss. He was a trainer for a ton, a ton of years. He knows controls, Danfoss controls inside and out. And he moved into this new position.
And this is what I. I talk about in the CO2 or the supermarket program, or even a compressor masterclass one, the advanced service one is that, like, for example, a Delta pi, A Delta P, they have multiple ones. They look the same, but they're different timings different alarms. Sometimes this is so key.
And just even on compressor, that's one component to the main component of a system. It's moving the heat around. The system and in learning about the compressors, he was talking about an application with me that he's never worked on before. ? A really ultra low temp applications to see if that, that, that could fit where I've done lots of that application specking before, and looking at different specs for different applications for when you're doing really low temperature, medium temperature.
Centrifugal compressors move heat, you know, slinger compressors move heat, semi hermetic, move heat. Well, like all these different compressors, they move heat, but they move it in different ways. And what do I mean by that? Well, there's different components. Even in semi hermetics, if you look inside a Carlisle, inside a Bitzer, inside a Copeland, inside of Bach.
And then delta reads. So which changes stuff up that the head, the valve plates a little bit different than the flow rate through it. But when they went from discus two to a discus three, they tried to make the. The body's more efficient, the way the flow through, the way to cool the motor. And then this is the difference between the different manufacturers.
The way it works, it comes back through the suction. It will usually go down through the oil check valve, and then it would be picked up through the oil pickup too. And screen. So it'll be picked up and then the pump would start to move it through and wash away all the oil on, on, on those ones. But you have certain compressors like the bitzer disc style.
It's like scroll compressors. Copeland has dozens and dozens and dozens of different scrolls, but some of 'em have the TOD temperature operating disc. Some will have the internal line protector. Some will have the high pressure, inter inter relief pressure, IPR inter pressure relief valve inside them.
That's a low temp. Copeland, there's more numbers to it. The capacity, the voltage and all that stuff. You need all that stuff. Take a picture of it, but just dove into that compressor. And I know it's been using Copeland Mobile lately in some of the trainings where you write in the model number, then all of a sudden you go to their publication application in bulletins, they don't match up.
So you need to get in there and understand how they work. I had someone. Recently that I talked to is like, I think there's an issue with the IQ module. Something's not working, that's not changing over, and then we dove into the manual and then it, it's like a, a setting that's not correct or it's a dip switch that's off, or that it's not been set up properly.
So there's lots of different. Ones, depending on the, the manufacturer. Then you get the old, old school oil pot ones out there. So there's lots of different oil pots. How do they all work? Well, they work in a similar way. The whole thing they're trying to do is maintain the correct oil level for that compressor, so we don't run outta oil.
So it's usually PTC that I've seen inside there. So as that temperature starts to rise, all of a sudden that resistor starts to increase in resistance. As that resistance increases, it sends a signal back to the controller. This controller could be the INT say 69 or the bitzer se B two or B three, I believe SEB two or B three.
There could be many things. Could be start and stop issues, right? We're not getting any cool BA gas back to cool that, but we know that resistance is too high and we gotta trip and we trip it off. And don't get me wrong, sometimes it is the modulate the themselves, so like the COR sense protection. Tro these, the CRE one INT modules, whoever, whoever modules you're using.
They are machine products. They bounce around, they travel around the world. But. One of the things is it's a lot of the times before you replace any component, you got to really check everything. 'cause if that, those re, that resistance is going up and it's tripping off, something is causing it. Or it's the resistant resistors in the compressors themselves.
You know, so what we need to do, I know there's lots of time where you get so many calls. I talked to someone in a training today, 85 hours. They worked last week. Just a crazy, insane amount of hours. And that's so many. That's too much. The thing is though, is that you gotta find time to find that root cause of an issue.
'cause that oil level control, the oil proof could be or the compressor proof could be tripped, but it could be because of the oil, or it could because of the condenser, or it could be 'cause of the level of the refrigerant in the system. There are so many different things. You don't want to just be replacing parts to replace parts.
You know, it's a system related issue. You just can't figure it out. So you clean it and you fix it, but you gotta go back there and solve the problem. Well, is it a wiring issue? Is it a defrost issue? Is it a time clock issue? Is it the termination issue? Is it the gasket issue? Whatever. ?
(00:22):
They were a technician. They were the technician before they owned the, the company, or they owned their own business and they're like. Trevor, I'm trying. I was always trying to be the most efficient as possible, and it's different than the way it is. A lot of it is today. Hopefully you are that efficient technician.
The thing is, is that like he would set up for the next day already, he would prep if he knew he was gonna do that compressor replacement the next day. It was urgent. He can't get the compressor until the morning he was. Unhooking the compressor that was failed, that's not pumping. He was unco unhooking the w wiring, isolating it properly, unhooking the wire, disconnecting the compressor, having everything else isolated even everything ready to go, all unbolted and all he needs that day.
And I know some of you think, well, it's, it's an eight hour job. Two guys, well, what am I gonna do? You wanna be efficient for your company? Okay. You wanna be efficient for a gun? Yes. Jobs can go sideways a hundred percent. I know you're thinking, and some of you're thinking, well, what happens if this happens?
But get back to my point is that a lot of the times that you get a job that you have to go and replace a compressor, but you didn't deem it fail. You need to do a quick check before you even start to install. The other one quick check could be the voltage on the old compressor before you even pull that compressor outta your truck.
Inside to move more refrigerant, right? It can move more. It could. It, it can. And this is, this is why it's important when you get there. So look at the old one, look at the mall number. Take a picture of it. Where are you at at that point? Now you go look at the new one. Is this the right one? So instead, spend on a, like six or seven hours, you know, getting the, the compressor up there, putting in a place, wiring up, and then just before you turn it on, 'cause I've done this before, and you realize it's the wrong compressor.
That's why you wanna come to the Refrigeration Mentor Training Program to learn to troubleshoot better, to save yourself time and stress. 'cause you're saving yourself when you start to save yourself stress. You're saving yourself time. It all all equals out. Back to saving time. How can I be more efficient and effective?
So there's so many different scenarios. I'm not gonna go through them all, but I want you just to recognize this is not one size fit all, but I'm just kind of giving you advice where I didn't have that advice. You know, and then I got it after I did make the mistakes and then I talked about it more. But I'm talking to all these different owners and managers and lead technicians and expert technicians who, who are really wants to help the industry, and this is why we do this stuff.
All the customer already purchased it and we're already quoted. Job. Do you know what I know? Great. Contractors and the top contractors own up and say, I made a mistake. I don't need to actually do this full compressor replacement. It is actually this. It's the valve plate or it's the contactor or, or whatever it is.
So we're only gonna have to, to pay the first, first charge or a certain charge versus the full charge. And you work with this, with your distributors and your customers. As well as your, your client. And I know this is hard to do, but this is as you build more relationships because you want to check that compressor because maybe you can find out what the actual problem is on that last compressor.
And that is not actually a problem. Actually, the problem is the compressor. The compressor needs to replace. But we're gonna have six more guys going over the next three months to look at these problems 'cause an oil issue. But it. The first one if I would've did a blow by check. We know that compressors cylinders are war.
Okay. Even within the same brand, a manufacturer. Two cylinder compressors, three cylinder compressors, four cylinder compressors, six cylinder compressors, eight cylinder compressors. They are going to work differently, even six cylinder versus six cylinder with inside. The same manufacturer like Bitzer will have splasher Flinger dynamic disc disc.
And this is where I've been just really leveling up on my compressor knowledge heavily over the last couple years because I've been just reading so many different manuals and, and just learning the different uniqueness of each brand. Man, it's, it's, it's been great. And I just, just try to, to spend a little bit of time just even finding a manual, if that's all you can do over the next week.
I know there's a lot of new people, there's lots of turnovers at the different manufacturers. And experienced guys that have been doing it 30 years are, they're, they're, they're starting to give retire industry. So don't give up. You know, find those manuals, read them a little bit off and on. Just get into them.
They work ice machines, they work differently. I love this. I love these sessions. Hope once again, hopefully you're taking a few things. Head to refrigeration mentor.com/hub if you want to get into the refrigeration mentor communities. This is the free community where you come in. There's challenges where we can chat, get to know on each other.
And sharing it with them because we are all learning different ways. And maybe this is one way somebody learns and they didn't know, know about the podcast, or maybe somebody finds out about it and it really helps change their career. And that that is the HVAC Mac, that's who it was on, on Facebook.
What's up everyone? Welcome to the Refrigeration Mentor Podcast. I'm really pumped up once again that you're here hanging out with me. Listen to me just for a little bit. Hopefully you're taking things away. This is what it's about. Learning a few things and going, applying it in the field. That is the biggest thing that if anything you take away is actually what we talk about here, is trying to go and apply it in the.
(00:01):
It is a hot summer. The biggest thing is, is that people are starting to realize that we need training consistently, yearly. There's companies I'm working with and technicians that I'm working with, like Trevor, I know it's busy, but I gotta schedule some time for training. You know, there are times when they're working 60, 70 hours a week and they're still showing up for the training.
And this was really good. Refrigeration technicians, good ones will admit that they make mistakes and often we make mistakes. And it could be from a little mistake to a big mistake. And the biggest thing is that one of the hardest things is, is owning up to your mistakes. And it doesn't matter if you're refrigeration or not, but a lot of the people that come to the training program talk about it and how they overcome some of their mistakes.
I don't know if I went and did something or not, but I came back and the pump was burning hot and it wouldn't pump. It wasn't pumping. I filled it up with oil, turned it back on, dead. It would not pump. So what happened? I just burnt out the pump because there was no oil in it. And that there, even that there, that's that's an expensive component.
One example, I, I do, when I talk to a lot of. Managers and business owners, or even just lead technicians is a mistake that younger techs may is calling multiple technicians on for the same problem. It's okay to call different technicians about different problems, but call 'em four or five technicians in one hour on the same problem.
It doesn't mean that you're not gonna get to the same result, one may take longer than the other. So that was one of the things that you know, really is key to understanding is talk with one. Technician, and this here is another learning step for me. That was a learning step. 'cause I did call a few different technicians.
So I talk about compressors a lot. I was talking to my good friend Ernie today. He is now the Lee, a technical manager of. For, for Bach. Now he's a, he is a control expert. Danfoss. He was a trainer for a ton, a ton of years. He knows controls, Danfoss controls inside and out. And he moved into this new position.
And this is what I. I talk about in the CO2 or the supermarket program, or even a compressor masterclass one, the advanced service one is that, like, for example, a Delta pi, A Delta P, they have multiple ones. They look the same, but they're different timings different alarms. Sometimes this is so key.
And just even on compressor, that's one component to the main component of a system. It's moving the heat around. The system and in learning about the compressors, he was talking about an application with me that he's never worked on before. ? A really ultra low temp applications to see if that, that, that could fit where I've done lots of that application specking before, and looking at different specs for different applications for when you're doing really low temperature, medium temperature.
Centrifugal compressors move heat, you know, slinger compressors move heat, semi hermetic, move heat. Well, like all these different compressors, they move heat, but they move it in different ways. And what do I mean by that? Well, there's different components. Even in semi hermetics, if you look inside a Carlisle, inside a Bitzer, inside a Copeland, inside of Bach.
And then delta reads. So which changes stuff up that the head, the valve plates a little bit different than the flow rate through it. But when they went from discus two to a discus three, they tried to make the. The body's more efficient, the way the flow through, the way to cool the motor. And then this is the difference between the different manufacturers.
The way it works, it comes back through the suction. It will usually go down through the oil check valve, and then it would be picked up through the oil pickup too. And screen. So it'll be picked up and then the pump would start to move it through and wash away all the oil on, on, on those ones. But you have certain compressors like the bitzer disc style.
It's like scroll compressors. Copeland has dozens and dozens and dozens of different scrolls, but some of 'em have the TOD temperature operating disc. Some will have the internal line protector. Some will have the high pressure, inter inter relief pressure, IPR inter pressure relief valve inside them.
That's a low temp. Copeland, there's more numbers to it. The capacity, the voltage and all that stuff. You need all that stuff. Take a picture of it, but just dove into that compressor. And I know it's been using Copeland Mobile lately in some of the trainings where you write in the model number, then all of a sudden you go to their publication application in bulletins, they don't match up.
So you need to get in there and understand how they work. I had someone. Recently that I talked to is like, I think there's an issue with the IQ module. Something's not working, that's not changing over, and then we dove into the manual and then it, it's like a, a setting that's not correct or it's a dip switch that's off, or that it's not been set up properly.
So there's lots of different. Ones, depending on the, the manufacturer. Then you get the old, old school oil pot ones out there. So there's lots of different oil pots. How do they all work? Well, they work in a similar way. The whole thing they're trying to do is maintain the correct oil level for that compressor, so we don't run outta oil.
So it's usually PTC that I've seen inside there. So as that temperature starts to rise, all of a sudden that resistor starts to increase in resistance. As that resistance increases, it sends a signal back to the controller. This controller could be the INT say 69 or the bitzer se B two or B three, I believe SEB two or B three.
There could be many things. Could be start and stop issues, right? We're not getting any cool BA gas back to cool that, but we know that resistance is too high and we gotta trip and we trip it off. And don't get me wrong, sometimes it is the modulate the themselves, so like the COR sense protection. Tro these, the CRE one INT modules, whoever, whoever modules you're using.
They are machine products. They bounce around, they travel around the world. But. One of the things is it's a lot of the times before you replace any component, you got to really check everything. 'cause if that, those re, that resistance is going up and it's tripping off, something is causing it. Or it's the resistant resistors in the compressors themselves.
You know, so what we need to do, I know there's lots of time where you get so many calls. I talked to someone in a training today, 85 hours. They worked last week. Just a crazy, insane amount of hours. And that's so many. That's too much. The thing is though, is that you gotta find time to find that root cause of an issue.
'cause that oil level control, the oil proof could be or the compressor proof could be tripped, but it could be because of the oil, or it could because of the condenser, or it could be 'cause of the level of the refrigerant in the system. There are so many different things. You don't want to just be replacing parts to replace parts.
You know, it's a system related issue. You just can't figure it out. So you clean it and you fix it, but you gotta go back there and solve the problem. Well, is it a wiring issue? Is it a defrost issue? Is it a time clock issue? Is it the termination issue? Is it the gasket issue? Whatever. ?
(00:22):
They were a technician. They were the technician before they owned the, the company, or they owned their own business and they're like. Trevor, I'm trying. I was always trying to be the most efficient as possible, and it's different than the way it is. A lot of it is today. Hopefully you are that efficient technician.
The thing is, is that like he would set up for the next day already, he would prep if he knew he was gonna do that compressor replacement the next day. It was urgent. He can't get the compressor until the morning he was. Unhooking the compressor that was failed, that's not pumping. He was unco unhooking the w wiring, isolating it properly, unhooking the wire, disconnecting the compressor, having everything else isolated even everything ready to go, all unbolted and all he needs that day.
And I know some of you think, well, it's, it's an eight hour job. Two guys, well, what am I gonna do? You wanna be efficient for your company? Okay. You wanna be efficient for a gun? Yes. Jobs can go sideways a hundred percent. I know you're thinking, and some of you're thinking, well, what happens if this happens?
But get back to my point is that a lot of the times that you get a job that you have to go and replace a compressor, but you didn't deem it fail. You need to do a quick check before you even start to install. The other one quick check could be the voltage on the old compressor before you even pull that compressor outta your truck.
Inside to move more refrigerant, right? It can move more. It could. It, it can. And this is, this is why it's important when you get there. So look at the old one, look at the mall number. Take a picture of it. Where are you at at that point? Now you go look at the new one. Is this the right one? So instead, spend on a, like six or seven hours, you know, getting the, the compressor up there, putting in a place, wiring up, and then just before you turn it on, 'cause I've done this before, and you realize it's the wrong compressor.
That's why you wanna come to the Refrigeration Mentor Training Program to learn to troubleshoot better, to save yourself time and stress. 'cause you're saving yourself when you start to save yourself stress. You're saving yourself time. It all all equals out. Back to saving time. How can I be more efficient and effective?
So there's so many different scenarios. I'm not gonna go through them all, but I want you just to recognize this is not one size fit all, but I'm just kind of giving you advice where I didn't have that advice. You know, and then I got it after I did make the mistakes and then I talked about it more. But I'm talking to all these different owners and managers and lead technicians and expert technicians who, who are really wants to help the industry, and this is why we do this stuff.
All the customer already purchased it and we're already quoted. Job. Do you know what I know? Great. Contractors and the top contractors own up and say, I made a mistake. I don't need to actually do this full compressor replacement. It is actually this. It's the valve plate or it's the contactor or, or whatever it is.
So we're only gonna have to, to pay the first, first charge or a certain charge versus the full charge. And you work with this, with your distributors and your customers. As well as your, your client. And I know this is hard to do, but this is as you build more relationships because you want to check that compressor because maybe you can find out what the actual problem is on that last compressor.
And that is not actually a problem. Actually, the problem is the compressor. The compressor needs to replace. But we're gonna have six more guys going over the next three months to look at these problems 'cause an oil issue. But it. The first one if I would've did a blow by check. We know that compressors cylinders are war.
Okay. Even within the same brand, a manufacturer. Two cylinder compressors, three cylinder compressors, four cylinder compressors, six cylinder compressors, eight cylinder compressors. They are going to work differently, even six cylinder versus six cylinder with inside. The same manufacturer like Bitzer will have splasher Flinger dynamic disc disc.
And this is where I've been just really leveling up on my compressor knowledge heavily over the last couple years because I've been just reading so many different manuals and, and just learning the different uniqueness of each brand. Man, it's, it's, it's been great. And I just, just try to, to spend a little bit of time just even finding a manual, if that's all you can do over the next week.
I know there's a lot of new people, there's lots of turnovers at the different manufacturers. And experienced guys that have been doing it 30 years are, they're, they're, they're starting to give retire industry. So don't give up. You know, find those manuals, read them a little bit off and on. Just get into them.
They work ice machines, they work differently. I love this. I love these sessions. Hope once again, hopefully you're taking a few things. Head to refrigeration mentor.com/hub if you want to get into the refrigeration mentor communities. This is the free community where you come in. There's challenges where we can chat, get to know on each other.
And sharing it with them because we are all learning different ways. And maybe this is one way somebody learns and they didn't know, know about the podcast, or maybe somebody finds out about it and it really helps change their career. And that that is the HVAC Mac, that's who it was on, on Facebook.
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