Hey thanks for watching this video. This is one class from the 2022 hvacr symposium in claremont florida. We have the symposium every year and so to find out more information, kind of upcoming go to hvacrschool.com symposium big thanks to our sponsors. For this event, which was accutools and truetech tools, they're the two title sponsors that made the event possible.

This class is with trevor matthews from refrigerationmentor.com, where he does a compressor, teardown and troubleshooting class, always valuable hope you enjoy. Okay, welcome! Welcome to this amazing event. This is the hvac sierra training symposium. The first thing i want to do is thank the host brian, the team here at kalos.

Anybody that you see that has an adventure or not you've got to say thank you they're doing a great job here, and i really appreciate all the things they've done um for these events. This is the third time here on speaking first two times i worked at a company called copeland, so a lot of you know that, and now i'm with a company called refrigeration mentor, my own company to help educate and train technicians in the field, and my talk Today is going to be on compressors, it's called a compressor story and because i really believe that every system has a story and as a technician, we need to understand that story. When you start understanding the story of the system, you can troubleshoot it quicker. You can troubleshoot it faster and be more effective and confident at your job.

So a little bit about me, i'm not going to go through it too much. I'm a first generation refrigeration mechanic so started out in 2004. Didn't know what refrigeration was didn't know. What hvac was didn't have air conditioner in my house? I went to the grocery store and things were just i picked up.

It was already cold and in 2004 i met a guy when i was going back to school, because i did go to college. I did go to university, try to get a job there and i just didn't work out and because i had to go to employment agency to try to find work after going to all the schools spending. All this money so went back to the school and i met a guy and he said: i'm gon na do a refrigeration, you can travel and you can make money ding ding ding. I was really focused on that so 2004.

I took my first hvacr program and i started to like refrigeration in hvac from there i spent 10 years in the field working in supermarket refrigeration, commercial refrigeration. I got a license for australia. I worked all over australia doing refrigeration great experience what's great about this trade. What's great about refrigeration? Is that there's so much opportunity you put the effort in you can go anywhere in the world.

You can make a pile of money. If you want it, you can live the life that you want, and it's really important to understand that, because the more work you put in the better off it's going to be back in 2014 after i've done a lot of the field work. I started to have kids and i'm like an opportunity, came up at a company called copeland. I knew who copeland was, but actually it was for emerson and this opportunity came up and i was very scared, i'm like what do i do you know.

Should i take this massive pay cut and go work at a manufacturer and do something different or stay in the field, because i love the tools i love working on the tools i love fixing equipment. I loved helping those customers out when i fixed their equipment and how happy they were and say man. I had three technicians here before you and you're the first technician that understood my problem and fixed the problem. So i took this chance and i spent i went to copeland and i worked at this company for seven years as business development as a lead, uh field support as the national trainer.

So it's called hvac training and development specialist and my role was to go around and train manufacturers train technician, contractors, wholesalers on systems, refrigeration on compressors, so i have a little bit of experience behind me. Am i an expert, i don't believe i'm an expert. I'm still learning every day, just like all of you and today i want to talk about the story of a system, the story of a compressor, a few of the things that we're going to go through we're going to we're going to break down stories. The stories that you do day in and day out, when you're in the field, because every time you're on a call, there's a story behind that call.

And we want you when you start breaking down that you start to get to understand the equipment a bit more and when you understand equipment a bit more, it makes your job easier, because i know when i was in the field. I wasn't that confident. All the time i would walk into a room, a rack or parallel rack system. There is thousands of valves, there's dozens of compressors, there's pipes going everywhere and i wasn't very confident it took many many years.

I'm not scared to admit it like seven. Eight years before i started feeling confident going on call and even even at the 10-year mark, i still had some jitters depending on. If i never been on that type of system, when i was told about it, so we're going to talk about the story, we're going to get into how to prevent that story from happening again how to prevent these compressors from failing a second or a third time. I'm very passionate about refrigeration and i really enjoy talking to other technicians about this.

So let's try to make this an interactive session, we're going to do a teardown. We don't have much space here. So what we'll do we'll do our best, we'll i'll grab a couple? Volunteers, we'll put it out here, we'll put we'll uh. We've got some bolts loosened already, but i want to talk through the process and i want to ask the questions and what would you do if this compressor wasn't working and let's work through it together? As a team, because our industry, you need to be working as a team, when you work in a team environment, you get more stuff done, you feel more confident and when you go to a call, you can complete that job a bit quicker, maybe you're a phone Call away to your tech to your journeyman to that buddy, and maybe you just need to shoot.

You know just ask them some questions. I've seen this a lot. I've seen doing support many technicians where they call me up and they tell me. The answer is like: oh, that's the answer.

They just need to say it out loud. So maybe you have to do that. Sometimes so we'll do the teardown we'll talk about it, we're going to do a picture rapid fire. So i'm going to put up some pictures and i'm going to ask you what caused that failure? What caused that story? What caused that issue and then we're going to get into some resources that i use that you should be using if you're not using, invest in yourself and do a little bit more learning.

I'm not standing here today, because i didn't do any learning. I spent years enforcing myself. Sometimes i didn't want to learn some of the stuff and it was hard and i didn't want to do it, but i did it because i knew i want to help others. I want to train and educate others, and hopefully i can teach you at least one thing today.

My goal here today is you take one thing away, even if it's just oh that guy's good looking you know if you take that away, that could be it right. Okay and then continuing the learning journey, we'll talk about at the end, okay types of mechanical issues we're going to get into mechanical issues, because this is one of the things when compressors have issues and you have a failed compressor. I was there. I was in the field and i've done it for many years.

I'd go up to the compressor. It's electrically failed. It's burned out that compressor is not working anymore, so you you cut it. Take it out.

You bring it back to the supply house the whole center and say i got ta burn out. I got ta, i got electrical failure, i need a new compressor, but what caused that failure - and this is what you need to do. What is the story behind that? Electrical issue, because the electrical issue or electrical failure, is second or third cause of failure. Not the first cause there are.

There is when we talk about turn to turn short phase to phase short, grounded compressor, there's a lot of electrical types of failures, but usually it's a system related issue. So what is that story? Because eighty percent of the time, we think it's electrical failure, but eighty percent of time is that mechanical failure that cause the electrical failure - and this is what you need to understand: what is the story behind that compressor? So what is this? It might be hard to see what what what's wrong with this picture. What issues do you see with this compressor? This is a scroll compressor. Does anybody tell go ahead? Okay? Well! No! That's! Actually! Okay! I heard it over here.

That's copper plating! Okay, what causes copper plating, acid heat can but acid? How does acid so now we're getting into the story? We've got copper plating, it's caused by. How do you get acid in a system moisture? How does the moisture get in a system? Bad vacuum: bad evacuation that that's the the high level of it you could have. You know you know a broken braised plate, heat exchanger or something in there on a chiller. But it is really that installation right so now we're starting to get to the story.

Copper plating is something that i didn't really know about. Until i did that i worked at copeland. I work with the experts and i still have good connections with them there. They send me pictures all the time say trevor.

You need to get this information out to the technicians because it's just costing them time and money and stress, but this is copper plating, so we we figured out a bit of a story, but do you think this technician knew there was copper plating in that compressor? There's no sight glass on this compressor. You know so this compressor was electrically failed compressor. So here's the story that you need to understand. So now, if they didn't look inside this compressor, they didn't know there was acid in the system.

What do they need to do? Now, on a system like that, if they didn't look into it and or say they do, did look into, how do i fix that system now? What do i need to do flush it? Okay, flush? What else do you need to do the acid dryer, if you need to what else do you need to do? Do an acid test, maybe afterwards, depending on the size of the system? Now, if you're on a little tiny system, that's this big and the acid test costs more than the system. Then it's a different story, but when you talk on larger residential units, commercial systems, this is part of your job and as a technician, you need to think about these things that i didn't think about in the field you need to write down. We do need to do a follow-up call on here, because if i don't check, if there's acid in there after a few days a few weeks a few months, how long's that other one gon na last and then you got ta, go back and replace it anyway. And this is why you need to educate your customers, there's some customers that you know you're not gon na get through to them, but you as a technician, need to protect yourself and be very straight with the customer.

This is what you do need because they don't know they don't know. They just see the price a lot of the time. So this story here is that now, if the technician would open that up looked inside and said, okay, i know i need to do a flush in that system, because maybe it didn't really smell. We know that there's copper plating that was due to acid due to improper installation.

So there's a bit of a story there right - and this here once again is an electrical failure right. So now, if you don't have a sight glass and you don't investigate, are you going to do this every time you're going to cut open a scroll every time? No, no, definitely not, but when you do not know why that compressor failed, you may have to. Are you going to do it on the job site? No, but you bring it back and you learn afterwards. You cut it open, maybe on your own time, if you have to because that's going to help you and bring value to your customer to your boss.

I hear this all the time and i do a lot of training with technicians. Well, i want to get a raise. I want to get a raise. Why do you get a raise over the next guy? What are you doing more and above your role? Are you doing things like this writing out great detailed reports? Here's the follow-up, here's the extra work that you could do or have when it's slow.

You know it's very important understand that, so this electrical failure was really caused by a mechanical failure. What was really caused by the installation of that first install next one. I know it's real hard to see what is this? What's this liquid sludge, black oil? So it's a it's a valve plate. What's the valve is a valve plate supposed to look like that? No, so what what do you think all that darkness is from excessive heat? Okay, this is important to know now.

What's the story, what's the story, besides the uh, about this excessive heat in this compressor? If i didn't pull off the head, you still may be visual, because if you look your your greatest tools as a technician is looking feeling touching listening my buddies that have been in the field for 20 25 years, they can go and walk into a chiller plant. Walk into an industrial plant walk into a supermarket, they can listen. They'd be like. I know that compressor, there's something going on with that.

I can hear it, it doesn't sound right, leaking, it could be, could be leaking. So what causes overheat? What's the story behind this, because when you go to a compressor manufacturer, all the big ones, copeland bits or dan foss, all of them, caroline, you talk about all these compressor manufacturers. They have specialists that do not know the system know the refrigerant know the power. That's using it, but they know the story behind that compressor, and this is what we need to know as technicians.

You know, and i and i seen it firsthand - i inspected hundreds and hundreds of compressors when i worked at copeland and i work with these gurus and they're like trevor. I've been doing this for 20 years 25 years 30 years, and you know what the amount of compressors being open like a semi-hermetic like this is less and less, and i hear it from technicians saying well, i don't have time to do it, isn't that what you're Paid for well, i well, my customer doesn't want to pay me to do it. What do you mean your customer doesn't want you to pay? Are they following you around, seeing watching you maybe, but you have time to at least pull a head off properly. Once again, you guys all have to be safe, safe out there, because if you're not safe, you get hurt, you can't work, you can't get paid.

You can't take care of your family, so you need to understand that safely pump it down electrically, isolate it. Take the head off - and you see something like this: there's a story to be told. So what causes overheat now high superheat discharge valve what else dirty coils, so there's a lot of things. So this is part of the story, so you need to understand the story and walk through it as a technician and we're going to dive in anything.

That's bold. It's hard to see i'm going to dive into three mechanical failures today, so i don't have time to talk about all of them. What is this and i'm pointing at the sight? Glass? A bit more. I know it's hard to see low oil, fantastic low oil, on a compressor that has a side glass, that's kind of easy to tell what happens when there's no sight glass right, but why is there no oil in there? What's the story behind that pardon low airflow? Okay, what would low airflow cause build the oil up in there? What's that poor refrigerant philosophy? So all these different things are part of this story right.

What else causes loss of oil or low oil leak leak? So you go into there, you what's part of the story. Well, i'm looking for a leak. This is part of the story that you need to figure out. You need a checklist.

You need to take a systematic approach when you're troubleshooting systems, you can't be going in and shooting by the hip every time you need to take an approach, this step, this step, this step, this step, this step this step, and over time you have at the beginning, You have this massive list, but over time this list gets smaller, because you know what to do you can think about when i get into a site. This is what i need to look for, and this is why i need to look for it and it tells you the story because we're detectives and we need to build a case to figure out that problem, and so loss of oil is a big one. That was one of the things that was the hardest thing for me to understand: where's the oil, it's not in the compressor where's it at what else could cause loss of oil flooded starts wash out what else? Ah viscosity yeah so below zero poe oil is like molasses, so think of it gets super thick and it doesn't want to move so now, if all of a sudden, you have an issue with your defrost, maybe defrost termination, something when you're defrosting. You haven't gone into.

Defrost for a couple weeks, maybe all that oil stuck in there or freezes up it all depends right, but you need to understand the story. Pipe sizing is a huge one. That technicians do not understand. It took me many years, and only because i did go and work at emerson and copeland and did field support manufacturers and stuff to really understand it, but the value of understanding how the system's pipe as a technician.

You want to be the best technician out there. You understand how to size a system: how to install a system, how to commission a system how to start a system up how to maintenance a system - and it's not easy you're not going to learn this overnight, because i tried to do it and i'm doing it. For 17 18 years now - and i feel like i'm at day - one okay, but take the time to understand all those different things and pipe sizing - is a huge one. If you have a 12 psi pressure drop in your suction line, there's something wrong.

Is there a restriction? Is there the velocity issue? You need to understand this stuff. What else is wrong with this picture? Besides no oil in there a true craig case heater. So now, if we think about this well, why did i put another crankcase? Why do you think this person put a crankcase heater there? Probably because maybe because they're having oil return issues now what would happen now, if that heater? For some reason, the auxiliary that pulls that in and off turns it on and off fails? Is that going to keep that compressor cool, or is it going to heat it up yeah? So you look at any compressor manufacturers they're going to tell you where they want to see that that crankcase heater and it goes in a specific spot. It goes in a specific i didn't know.

I didn't know you need to put it over the seam. The weld seam and it'll tell you from the base, depending on the manufacturer, tell you how high they should have it, because if you have it too high, it's going to overheat the compressor potentially next one anybody ever open a scroll bush 4 show hands. Chris has built a couple: people if you haven't opened a scroll you need to. You need to take the time, even if it's not on a job.

Where did okay? How about this? Where does the scroll go? It's unwarranted, no warranty on the scroll compressor. Where does it go? It goes in the scrap bin, so your job is now. I challenge all of you here and everybody that's online watching. I challenge you when you have a failed compressor, it's out of warranty and it's going to go in the bin.

Keep it cut it open safely, safety, glasses, gloves, a good sawzall or a zip cutter. Some people use plasma cutter, but i challenge you to look inside to figure out why that compressor failed. Is that a warranty anyway? It's going away! You need to understand this stuff, because if you don't know that story, how long until the next one fails - and it's very important as a technician to understand the story. When you understand the story of that system, you know how to troubleshoot it.

Your confidence is going to go up because you're going to figure this out the story. Okay, this one here flooded, starts these special inspection people that work at these large manufacturers like bitser and copeland and carlisle. They look at these pictures and they can tell you what caused that failure, but - and they can tell what the technician thought the failure was. Okay, so like this one here, electrical failed compressor.

You see this is called something called scroll galling, so it's actually metal on metal there's supposed to be a nice foam of oil in between there, but you get what's a flooded start. How does a flood is start even happen and we're going to dive into it? How does the flood is start? What causes the flood to start liquid migration? Okay, because refrigerant wants to go to the coldest part of the system? Well, why? Why would it want to go to the compressor? Oh it's outside, and it's cold? Okay? Well, so what are you gon na do to prevent that then crank case heater on it, maybe a second or third one. If you need to hey bill, no, what else pump down solenoid we're going to talk about this a little bit more, but it's important to understand it. But if you didn't look inside this compressor and you put another one back in i've, done it tons of times, i put a new compressor in i.

I tried to find out that issue. What caused me to be here to fix this compressor has electrically failed and i there was times uh must been the relay it was loose, the wire was loose. I did it, but you know what i didn't know the story of that compressor because i didn't cut it open. I didn't look inside you work on semi-hermetic compressor.

You need to look inside them. What do you need if you take a head off of a compressor? What do you need? What is the one thing you need? What is this safety glasses? Okay, you got the safety glasses, you bump it down properly. You got electrically isolated. You take that head off.

What do you need if you're going to look at it? You need gaskets, okay, and if you don't have gasket there, you put the head on. You call the the whole the wholesaler upper supply and say: do you got these guys to order me some i'm going to put it back on for now and i'm going to have to come back and do a follow-up, because it's like your car engine, you're working On your car, you pull your head off your car engine. Are you going to leave that old, gasket on your head, yeah, yeah, so and then here's a picture of a semi-hermetic? So if you take the pump off we're going to talk about this in the tear down, when you take a compressor apart, send me a hermetic. You don't have to pull the whole thing apart.

You don't have to do what they're doing at the manufacture level to inspect it. You need to take a few things off. You need to pull off the head safely. Take a look inside, you need to pull off the pump and look inside there and that's really all you need to do.

If you want to dive deeper and pull the stator cover off and look you can you can totally do that, but it's not necessary to find the different tips and tricks that we'll talk about today. Next one, what do you think cause these failures are issues? It's logging, yes, okay, let's start of the story of a slug. How does a slug happen? How do you have a compressor slug? That's a txv! I stuck over only on one type of compressor, not regular, not a refrigerant cool compressor, an air cooled compressor. Yes say what was that again: improper superheat? No, not for slugging good good, try what caused a refrigerant cool compressor, which are scrolls, which are semi-hermetics, filtered right out.

Well, that'll, be restriction, no close start, stop. Okay, start stop we're getting closer, but most start stop. Is oil issues, oil issue? What causes the slug? This is very important as a technician. You need to understand this proper charging.

Okay, what would okay? How would something break inside a compressor is what what's supposed to be in a compressor? How about? Let's start there? What's vapor, okay, what would cause that would vapor cause that? No, so what could cause that? What are two things that could cause that liquid? I love that liquid because i used to say liquid too, and i was really corrected by manufacturers when i worked for them, because what do you mean by liquid now, liquid refrigerant or liquid oil right could be two different things, but you need to understand so now. Liquid now i get liquid in there. How do i get liquid in a compressor, it's not boiling off, but when it doesn't boil off in the evap? What does that consider that that's flood back right? So how do i get refrigerant in a compressor to do something? Like liquid refrigerant, what is the the one that we just talked about? Just before flooded starts. How many people know a slug was caught, is caused by a flood start show of hands and refrigeration cool cover.

To be honest, okay, this is important. This is key information. You need to understand that flooded start because we talked about it. Chris said that refrigerant migrates back to the compressor, it condenses it stratifies in the oil it stratifies, the neuron, that compressor starts up and it bang it causes things like this causes things like this, and things like that.

So now, when you think about the story, okay, so the system is off, the auxiliary. Contactor failed. The crankcase heater was not working at that time or it failed. The refrigerant migrated back to the compressor.

The compressor was off for a long period of time. So it's stratified in the oil, the refrigerant and when that compressor started up bam, you had a flooded. You had a flooded start, a massive flood of star which caused a slug. So now here's the story, you know they could.

You could go, and you put your gauges on this compressor now and the compressor's still electrically running or it could be electrically failed because you put your gauges on this compressor right here. What are your gauges going to say, it could say equal yeah because there's nothing running nothing pumping, maybe a few psi off, but you need to understand it. But if you don't look inside how do i know it's a slug that did that? How do i know it was a flood of start that was caused by the slug, so this is what you really need to understand when you're doing any type of system it doesn't even matter if you're working on smaller equipment, you want to understand what caused that Failure because, when you understand that what caused that failure you're going to change your troubleshooting game, okay - and i missed it a little bit on loss of oil because i'm not going to dive into that a little bit deeper. A lot of you work with compressors, with no sight glasses.

Is that correct? Okay, you have a compressor fail with no sight glass. What is the one thing you have to do the compressor's failed, and you need to do this every time to make sure you understand that system that story. What do you need to do? Pour it out and measure it compared to what that manufacturer says, because what, if you take it out and you dump it out - and it says it should have 20 ounces of oil or yeah or milliliters wherever you're listening from, and it's only had two ounces. What does that mean now that soil, oil, somewhere okay, it could be leaked out? Like you mentioned, it, could have had a leak, but you walk around and there's no leak.

There now where's the oil it could be in the evaporator. So now that compressor, how would it fail if i had no oil in that compressor, say the the one would go back to the one with no sight glass you're working on it and it failed. What would it happen that failure, because all the oils in the evaporator will say what was that failure shavings locked rotor, who said it great job, seize compressor because you got no oil, it's just like a current and you drop. The oil in your car energy go drive 100 miles, see what happens.

Okay, so you're going to have a seize compressor so that first compressor is going to fail by a seize compressor. So you take a new compressor. You put it there from your service replacement from your wholesaler and you stick it and you install it. Okay and the compressor it starts to run, and then two weeks later or a week later, you get another failed compressor.

Do you think it's probably a seized compressor again could be a seized compressor, but it could be too much oil right now. You got a slug because you got too much oil, so these are the things that you need to think about when you're making building your case when you're troubleshooting - and you know over time - it'll get quicker and faster and easier, but you got to start somewhere building That story building that case. Okay, here's one more last one, there's a little bit: there's the crank, scored crank. Yes, why is it scored like that, because it can score that way, different ways spawn a bit yeah, it's one bearing how do you spin a bearing in a refrigerant cooled, semi-hermetic compressor, just like this? No oil, but how come there's? No oil wash out okay and what causes a washout liquid flood back.

So here's the story. Do you see how we're coming up with pattern of how this is happening and there's a ways to test this stuff to understand what caused that compressor to fail? This one here is something called shake hands with the crankshaft and we'll talk about that. A few simple tests things to look for is going to make your job super easy: okay, compression ratio. What is compression ratio? Okay? Yes, so your absolute discharge over your absolute suction? How do you get absolute now? Yeah, it's absolute pressure.

14.7. Absolute sorry, 14.5 would be bar, so 14.5 is bar account. Another unit of measurement 14.7 uh atmospheric pressure, so you depending on where you're at or if you're up at a higher altitude, is going to be different. But here here is 14.7, i say: 15., don't even use that number.

So i use 15.. So you have for an example: you have 275 psig, you add 15. You get 290 psia! Okay! Then you get your suction 55 plus 15. Psi is 270 psi.

A sorry. 270 psia, you divide them and you get 4.1 compression ratio. Why you tell me this trevor? Why does this even matter? Well, compression ratio is very important, because what does compression ratio do to the system an operation envelope of a compressor? Why would i even tell you this everything's designed around that everything? Is it? Do you think, a high temp application, what about a ultra low temp that runs into a vacuum? Your suction? You know, i'm just you know, but different application will have different compression ratio. Compressors are designed differently.

You cannot take an air conditioning compressor and go through in a low low uh temperature application. Copeland does have a few that will do a wide range, but the standard compressor you're not just going to do that. They're designed differently they're built differently because of different compression ratios, okay, and why this is important, because when you have high compression ratio, what does that do to the system to the compressor into the story of it? What is it heat? Someone a lot of heat, a lot of work, it's doing a lot of work that does not really necessarily need to be done. So what would cause high compression ratio now overcharge dirty coil? There's a list and list of these things: low, suction pressure? What's worse, high discharge or low suction now, so how about this? How about high discharge you're going to have a higher uh higher compression ratio, show hands how about you're going to have higher compression ratio with a low d, a suction? We got four, it is low suction.

So you got ta understand when you have that pressure drop in your suction line. That's way worse and you got ta understand what caused that you got. Ta figure out that story so for people that do metric 19 bar plus one bar. Now you see, i do one, but it's really 14.7, but then you do the calculation again 20 bar over five bar.

You get four to one compression ratio way easier, matt, hey the thing about it: it doesn't matter what units you use high low temp application, you're gon na be like 10 to one we'll, say medium temp, five to one uh air conditioning two to three to one. Besides co2 refrigeration, i'm not going to get into that, but sub critical applications are really low compression ratio. But if you don't understand compression ratio - and you don't understand that it's building and causing a lot of heat, you're missing a part of the story, it doesn't take long to start learning this a little bit more. I got a picture always check the discharge temperature from where how far six inches excellent okay and then you want to keep it below what, when you check it 225, who said 250 there you go you're, not wrong because bitzer says 250, copelan and carlisle say 225..

So it depends the manufacturer who you're working with this is stuff. You want to understand. I would say 225 anyway, because you're on the safe side, because inside the head of the compressor right at that discharge, point right where it squishes that last piece of gas, that's the hottest point same with the scroll right when the scroll or a screw compressor. Doesn't matter right at that last compression? That is the hottest point so from six inches inside the compressor, it could be 50 to 75 degrees hotter.

What happens to poe oil when you get it over 300 320 starts to lose. Lubrication 350 400 starts to break down. So you need to understand this. Okay, and this is right here.

Every one degree increase in your suction is one degree in your discharge. Doesn't matter what units you're using you need to understand that, because, if your return, gas temperature, your suction gas temperature, whatever you want to call, because there's so many terms in hvac and refrigeration, whatever you want to call, you need to check that. What is my return? Gas temperature: what is my suction line temperature? What's my suction gas temperature, because you need to understand this is a refrigerant cool compressor. Why am i coming with 75 degrees back to this compressor and i'm trying to get a 35 degree? Evaporator high return gas temperature, no insulation on the suction line, so you have a chris had a great video.

I watched one time where he's showing that the line says running across the roof, the suction on the roof and the the insulation is failing. So as a technician he commented on it, look at this insulation. It's bad! You need to do this, you're a detective as a technician in the field. Maybe that customer's not going to want to change it, but you got to know maybe i'm picking up 10 degrees.

More because of this line is not insulated properly. This is why the compressor is overheating a bit and it's going to fail and lead to a failure. Earlier. You need to understand that you need to build a case on every system.

You're working on you need to build that story. When you understand the story: you're going to troubleshoot faster and quicker okay operation envelopes, you really need to understand these. Okay, i got one here, courtesy of emerson, here's a a picture of their zf k5. This is an operation envelope, how many seen an operation envelope of a compressor before show of hands, not enough of you and that's okay.

But this is where you're going to start to learn and understand, because if the compressor, if the system's running here here here here here here or here here, depending on the motor and the bits, are compressor you're going to lead to a failed compressor and each one Of those things will say, it will tell you a sign. Well, i'm running at a super high suction when i'm up here. Why am i running at such a high suction? You need to think about that as a technique or you're running out here. Why is my low pressure control not cutting out before the operation envelope, because now i'm running outside the envelope doing work on that compressor, potentially causing damage? That's going to lead to an early failure and i've seen compressors are built.

These manufacturers, like copeland, bitter dan foss, caroli bach i'll name, a bunch of them. They don't build compressors to last a year or two, they last 10, 15 20 years. That's what they're built for, but us as technicians or the customer themselves. Not doing maintenance is what causing the failures earlier failures.

Do things happen? Yes, there are compressors that are you know at the factory that are not assembled properly, that make it out to the field by manufacturing. It does happen, but these large compressor manufacturers are they're pumping out good quality equipment. A lot of what i've seen and i've tore down. Hundreds of compressors is that it's system related issues and usually the story's not told they don't know the stories the people that are in the labs pulling them apart are telling the stories of the compressor additional cooling methods.

So if you work in low temp application - and i'm even seeing it in, i believe in heat pump application where you have something called liquid injection, you need to cool that compressor down, because the compression ratio is so high. Remember we talked about high compression ratio. High heat, so now you need some sort of additional cooling, it could be a tread valve, it could be a ddc, it could be a captive whatever it is, could be a fan, but you need to understand the story of the compressor, because if i'm running in This area, with this compressor on these refrigerants, specifically those refrigerant i need to have liquid injection, i need to - or the compressor is going to fail, so you need to understand the story. You need to understand that compressor that you're working on as well.

You need to understand the manufacture of it, because not every compressor is built. The same i used to think scroll's a scroll. It's easy. I know it's ac scroll over.

It's all the same. It's not google makes over 25 different scrolls. They work differently. They're different sizes, different components, different internals.

You need to understand that stuff. Does it take time? Yes, are you going to learn it overnight? No, but have you know, have the confidence in yourself to learn that and want to learn that chris point out that you need to be concerned with that, if you're converting the refrigerants too, because you could be using an r22 compressor and converting it to 448a, you Really really need to focus 100, so chris chris brings up a great point retrofits. How many of you done refrigerant retrofits, then? How about that anybody? Okay, you need to read some guides and learn about it. You go to sportlin a guide and they'll.

Tell you you need a size, that's a solenoid valve. You need a size, a tx valve, depending on what refrigerant you're, replacing it with and from r22404 and they're, going to say, you're going to have to change the valve, because the gaskets are not going to work or you've got a high percentage chance of leakage and I've seen this time and time again, uh contractors go in i'm just going to do a retrofit, we're just going to pull out the gas put the new gasket in it's a drop-in replacement, we're all good there's, no such thing as drop-in replacement to me. Anyway. Maybe you guys might think of it, but you do have to check superheat.

You do have to make sure it's the right oil. You do need to do all these checks. So for me, that's not a drop in replacement. If i have to do all these check, drop in replaces pull something out put it in and i'm gone, but that's what the technicians are doing and they're leading the failures, quick question: when you have high compression ratio, this will cause the compressor to what do less Work, flood back overheat run normal or slug.

Okay, we got that point across quite well: okay, flood. It starts. We talked about this. Why? What causes flooded starts liquid migration? Okay, so we got vapor coming back to the compressor it stratifies in the oil.

The compressor fills up with refrigerant and then bam. You got a good looking scroll set inside there. Scrolls are tough, though they can take a few of those, but they can't always hit them. I watch in the field many compressors by manufacturers get taken out and when you start hearing marbles in a scroll compressor, shut, shut it off i'll.

Tell you right now. The damage is really already done. To be honest with you. Maybe you don't want to shut it off, but when you hear marbles you're in trouble that compressor's in trouble, maybe you're not there's also another thing that you need to look for.

Maybe the refrigerant is coming from the discharge side, so you might need a check valve and maybe the manufacturer of the equipment didn't even know that this is why it's our job as technicians to dive in a little bit deeper, learn the story of the equipment. Learn the story of that compressor or that system do i need a check valve. But if you didn't open up this compressor, how do you know that it was a slug or a flooded start to cause a slug to cause a failure? Because when you go there as a technician, what are you gon na? Do you're gon na change it, but what's your first check the compressor's not running you're gon na check, if there's any gas and then what are? What are you going to do so? There's gas in it you've got gas in it. So you're going to take your meter out and you're going to check it and you're going to have a dead short or an electrical failure or turn to turn chart or phase a face short or winding short, whatever it is, or ground a compressor.

But if i don't know that took a slug, how do i know how to fix the problem? You're going to put a new compressor in you're, going to watch it you're going to turn it on, and it's going to work for four hours straight and you're going to watch it you're going to be like there's nothing wrong with this and what you know and Then i'll sign it off, i watched it. I got the right superheat, i wait till it came down and that was it. You walk away, but that night well you're not there and it goes into defrost and all of a sudden. The compressor washes out again or you get flood back at a certain time or at night that those end users they'll open the doors, they'll turn off the fans or whatever it is.

But if you don't look inside that compressor and you don't understand the story of the compressor you're just going to be replacing another one afterwards, okay, this is kind of what it looks like inside. You open it up and you see what we call what i call scroll going or they, the manufacturer, called scroll calling, and this is a flooded start. This is a slug caused by a flooded start, and this is three causes of failure. So remember as a technician you'll go up and now i got electrical failure, but this electrical failure was caused by a slug and that slug was caused by a flood assert you getting the story now, starting to understand that there's causes and effects, and this is as A there's three mechano, two mechanical issues that led to this electrical failure, and this is a technician.

What we need to know need to understand to be better to get better, so you feel confident when you say this compressor is a failed compressor. You know 100 is a failed compressor, because when i did work at copen, i've seen dozens and dozens and dozens of compressors come back. I put them on the bench and they run totally fine. There is nothing wrong with it and i'm talking about four thousand.

Eight thousand ten thousand dollar compressors and i'm running them on the bench and when i send it to the contractor, because i have some friends out there, they ask me trevor: can you inspect this when i work there and that's what i do and i send them A video of this 10 000 compressor running they're really upset their pride is hurt because they're a good technician, but they made mistakes and they missed something right and, as and they're like. Well, i didn't check that because i didn't know - or i forgot - okay flooded, star prevention, we talked about a crank key here. Pumped down cycle bump start cycle, put the compressor in a warp location. Okay, once again, if you have a compressor that is flooded starting, you can see it.

What do you look for? If you, your compressor, has a is off and it has a flooded start and has a cycle? What are you gon na? What are you looking for foam you're gon na go, look in the sight glass when it starts up. You look inside there and if there's explosion of foam in there that's liquid refrigerant inside there is there like a little. You know. Is there bubbles? Sometimes an oil want to start yes, but when you get a full thing of foam, you can tell that's a flooded start, and if that is happening, you got to figure out what is causing that and you need to stop it.

The damage is done. You're going to lose a bit of efficiency, i'm sure, but you can protect that compressor last a few more years and it's very important as a technician to protect that equipment for your customer because they don't know the difference. They're, paying you good money to do a good job, and when you understand what's going on in that system, it's going to make your life a lot easier. Okay, flood back! We talked about this already.

What causes flood back again? No liquid migration's flooded syrup. It's expansion valve, but what causes it like? What is it? What is actually what's the story? No, it's no superheat any time the compressor is running and liquid makes its way back to the compressor. That's what flood back is any time the compressor's running and liquid refrigerant's, making its way back. Okay, and so we heard okay, you can have an issue with your metering device that causes floodback.

What else causes floodback low airflow? What else causes there uh? Why? Okay? Now we can break down low airflow. How does low airflow have? How do you have an issue with low airflow? What causes low airflow fan is not fun. Coil's, dirty plug coil. Look the coat! Yes, all the couch look good in return.

So, look at all these different things that we're talking about to build that story. You know it could be one of those things, but that's part of the story. What one was it you need to understand this? Maybe it's a plug drain and the water filled up into the coil and it froze the coil up and then it stopped the airflow. And then now you can't boil off that refrigerant.

So now it starts to make it way back to the compressor, which leads to a flood back situation which causes that compressor an issue. Does it fail right off the bat? No, unless it's really really bad? It's like copper plating. I talked to my friend steve wagner. He works at the copeland plant and which one is it again: the sami hermetic plant anyway, he said trevor.

He sent me some pictures he's like look at this picture. I might have it coming up. I shouldn't talk about it, but anyway, i'm going to tell any he's like what's wrong with this compressor, i'm like it's copper plating. How long? How long do you think it's been running in the field two weeks because of copper plating? Okay, also, he sent me another picture see it looked exactly the same, exactly the same he's like trevor, how long? How long did that compressor run for was like two weeks? No, that was two years.

So you need to understand that copper plating for getting off topic here could be two weeks two months two years. So do a good installation there, tx valves metering, device, low airflow, anything that you cannot boil when you cannot boil off that liquid refrigerant in the evaporator, because you're supposed to absorb the heat there and it makes its way back to the compressor - is flood back. But you need to understand that story. What caused the flood back? Where did it start? How do i fix it? How do i make this not happen again? Okay, no superheat! So if you check and has no superheat it's bad, if you have a regular synthetic refrigerant and you're below 10 degrees superheat, you know at the at the lowest point that it could be well.

You might get away with it without causing a little bit of damage. 20 degrees, that's what copeland is looking for. Superheat back at the compressor 15 degrees is what bitser is looking for. So you need to look these different compressor manufacturers up.

But now, if i talk about new refrigerants, there's a refrigerant called r3513 - i don't know if you ever heard of that refrigerant. Yet, but now the minimum is 20 degrees. Super not 15, not 10. 20.

co2 could be 20 degrees or 36 depending on this transcritical operation or sub-critical operation. So you need to understand the equipment you're working on, and so you understand the story when you have an issue with the system. Okay, so if you see a compressor looking like this, you need to check the super heat to make sure. Well, this one here, i know for sure is, is flooded back, but if you don't take your gauges out, you don't take your temperature probe out.

You can't prove that it's flood back or not, because you could be doing a low, temp application, it's really cold you're below zero and there's lots of humidity that's gon na wan na that could be normal, okay and then inside a scroll. If you pull up part of the scroll apart and how to to open up a scroll, you safely pump it down to remove it you're out of it's out of the system. Now at this point, you want to put it on a pallet screw it down. Put it at c-clamps hold it down safety, glasses, gloves a good sausage and right below the line here.

Look at here. I got one done right here so right below this well mark you just go right around smaller compressor super easy to go open. Chris has done lots of time before the big compressor you're working on 40 ton. Compressors, it's a lot harder.

It takes a lot longer. You might need a few blades, but i say start with the small ones to look inside find out from your supplier. If there's, if it's warranty or not, you know just double check if it's out of warranty, it's fair game right so, but learn learn from that. Okay, flood back prevention, checking that subaru that we talked about.

Okay, if you're in a critically charged system, overcharging could be an issue, so you want to make sure that you do this and here's a bulletin from emerson ae221182. I recommend reading that book at that manual. I've read it dozens of times and i still learn stuff from it. So i want some volunteers.

Anybody want to volunteer to inspect the compressor with me. Okay, great! So what's your name! Stefan stefan trevor. What's your name alex alex nice to meet you alex? Okay, so compressor is out even if it's in first thing, what do you want to do check it electrically yeah, so isolate the power lock it out right, make sure that's done first, so you want to check it electrically. Okay, we got.

We did all the safety parts you want to check electrically. There's a there's, a meter right there do you want to check, check it and if you haven't used the meter before we'll figure it out together. Okay, all right, we've got resistance right. I haven't used this one yeah, that's okay, csr, so there's three leads on this one, and the first thing you want to check is make sure what type of compressor in it is it.

So we got it's a 208 230 volt, three-phase compressor, okay, step. One is checking the resistance: it's uh, l1. L2. L3.

It's three phase yeah between l1 and l2, 0.21 between l1. Okay. So do you see how stefan did it see how this is shaking right, like that? This is not the way you need to be able to do this. Okay, i've done it before, because now this is loose it doesn't you don't get a good connection, so the best way to do it is right from the tips and every compressor doesn't matter.

If it's a scroll you want to go right from these are the lugs that go right to the windings of the compressor, it's all over the place. Okay, so one thing you need to do and it doesn't matter if it's a scroll, it doesn't matter. If it's a semi-hermetic right here is something called an insulator plate, this little insulator plate right here and i've seen many many compressors come back when i was inspecting them for copeland come back and all it was. Was this insulator plate no different on scrolls they'll? Have a little like the little black insulator plate, that's on the scrolls you'll go right up to it and you'll check it and it's a it's a short it's a dead short, but the problem is: there's a carbon tracking on that insulator.

So you need to pull that off and do it straight from the compressor. So now he's going right from the compressor. Now we got .4, we had point 2 before and then we had something all over the place. Now we've got 0.4.3.

0.4. Okay. So that's good, but we're not done there because now, as you can see, there is another terminal plate a terminal plate right here. This could be the issue.

So this is where you need to dive in a little bit deeper. Okay, so i don't think those ones aren't loose, but this is very important to do because you don't want this is not a cheap uh compressor to replace, and let me see if we can. I don't know if this will do it. If yeah there we go.

Okay - and the thing is, if this is on the middle of a roof of a building, you got to get a crane. You got to get a team of guys, you got to get plywood and maybe put the plywood down and roll it across the roof.