Latest / The Refrigeration Mentor Podcast / Episode 250. Service Call Stories and Troubleshooting Tips with Andrew Freeburg

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Episode 250. Service Call Stories and Troubleshooting Tips with Andrew Freeburg · The Refrigeration Mentor Podcast

• 0:00
  Trevor: Andrew, welcome back to the refrigeration mentor podcast. How you doing brother?
• 0:01
  Andrew: Great. Trevor, thanks for having me here today.
• 0:02
  Trevor: So Andrew's out there crushing it day in, day out servicing stores on call. He he's in it in the deep of it. And we, we messaged you each other all the time, talking about different things that are going on in the field, but there was a few of the over the last few weeks that he's, he's ran into.
• 0:03
  He thoughts really good to, to share with you because if you're out in the field working on some of these components, maybe you don't see control all the time. Maybe you don't see, you know, you're working on ECM fan motors or VFD motors all the time. So we're going to dive into a few topics today, but I know you've been working on a project with a replacement of an EPR.
• 0:04
  You want to tell a little bit of what was going on with the EPR?
• 0:05
  Andrew: Yeah. So just give you guys a little background. This EPR was, is on a rack and on the header it uses cool gas defrost which takes the gas off top of the receiver to defrost the case. Well, every three to four weeks, the, the lineup freezes up.
• 0:06
  So then we have to manually defrost it. So I started checking this unit out. I manually put the unit in defrost and it has a suction stop. EPR on it. Well, if it's partially open, then that gas flows right back into the suction header, thus not really defrosting what you need to defrost. So with it being partially open, I'm like, okay, I just need to get the internals of that EPR and then we should be good to go.
• 0:07
  So I go order the PR. Come back isolate the circuit. So you'll shut the liquid line off first. I also shut the hot, excuse me, cool gas line off, and then pump it down and then get down to whatever rack pressure is in this case, I think it's right around 12, 15 pounds, if I remember right then I take my recovery machine and I hook that up and then I just dump that right into the, the rack itself.
• 0:08
  So, and then I get down to where there's no refrigerant left in the circuit. And then I pull the EPR off. So I pull the EPR off, put the new sort piston in there, throw it back together. The unit works just fine. I tested it through back in a D. Oh, well, you got to vacuum in a course, pull your microns throw the system back in, throw it in defrost.
• 0:09
  Everything's working fine when I was standing there.
• 0:10
  Trevor: Yeah. Always when you're standing there, cause that's, that's the thing, right? I remember so many times sitting at a rack on a bucket, the compressor won't trip off, you know, it had an oil issue in the middle of the night, but it won't trip off. And you sit there for two hours and nothing happens.
• 0:11
  Yeah. Okay. I must've, must've been a nuisance trip, but that's not, that's not the case.
• 0:12
  Andrew: Oh yeah. Those are the, those are the, what makes this trade fun. It's trying to figure out those really, really hard ones. And then those are your lessons that you learn. And you're like, I'm never going to forget as soon as you figure it out.
• 0:13
  I'm never going to forget that one, you know?
• 0:14
  Trevor: Yeah. So you replace it. It was working. Defrost was working. It wasn't blown by back into the suction header.
• 0:15
  Andrew: Yeah. So everything was groovy. So I left. Two days or three days later, they called me back, say that it's not working anymore. My case is not holding temps.
• 0:16
  So that's weird. Look up my gauges and yo, yeah, it's way too high a pressure. So I'm like, okay it's middle of the night. I'm just going to force the stem open, pull that case down, come back in the morning. So. Here I am, back in the morning, checking things out, like, okay, obviously it's something that I did, maybe I put something in wrong or whatever, pull it all apart, well, isolate the circuit, pump down, do the whole procedure, pull it apart, look at it, I'm like, well, I didn't put anything wrong, so maybe, maybe it just got jammed up again, I don't know, shoved it back in there, threw it back on, wasn't working again, so I'm like, okay, So I go out and grab my old piston, and I look at it, and on the very end, there's a little nipple on that piston.
• 0:17
  If you look very closely, there's this little tiny pinhole that goes through the piston. And down, down into the other, I guess the other side of the piston. So, okay, maybe that's the difference. I don't know. I didn't notice it on the old one. So again, bump it all down, do the whole procedure, pull it off.
• 0:18
  And I look, and this time, this one did not have that little hole in the piston. So, I just swapped the old little tiny piston, I changed over all the gaskets so it has the new gasket, put it back in there, shoved it in, and now the system's running just fine. But that little tiny detail is, is a, just was a learning moment for me.
• 0:19
  I will never, moving forward, I will never forget to look and see if there's that little pin, pinhole, and that And that sort of piston,
• 0:20
  Trevor: that that's very good. Like I'm going to reach out. Like I already mentioned to you, I'm going to reach out to, to Sporlin with that and ask them, send them a couple of those pictures because that is a very small detail.
• 0:21
  Why with one has a hole in it and the newer one doesn't what's the difference? Cause I'm sure bodies are still the same. Like it's not, maybe the body has changed a bit, but I don't know.
• 0:22
  Andrew: Yeah, the, the, the body is slightly different than, than the old one. So maybe that is the difference that it needs, but yeah, it was definitely, like I said a learning experience.
• 0:23
  Yeah,
• 0:24
  Trevor: for sure. And that's good. It's something that you're not going to forget. And so, and the big thing is, is that, you know, you can replace components sometimes, but there are other times that maybe you had to replace the whole valve itself. You saved you save time on just replacing the body, but you got to look how old is the body?
• 0:25
  How old is the valve? If it's all rusted out and everything that's you want to change it, but I know for sure, as we talked about, it wasn't that case, you know, changing the inside should have been an easy, easy replacement. But so, so that's a, that's a really good learning moment, which is, I know I've had so many of those when I was in the field, like.
• 0:26
  Oh man, you look so close. You look at the fine details, everything looks right. But then all of a sudden is one little thing is different and it makes that difference.
• 0:27
  Andrew: Oh yeah. Just a simple tiny pinhole is what could cause a valve to stop feeding. The only thing that is weird about this whole scenario is that it.
• 0:28
  Like I said, it was working fine for me the first time. And then when I leave and come back, so it makes me curious if I just left too early. That's why I like to change. Anytime I change any part out, I always verify operations to make sure that that. System is working before I leave. I never just change a part out and leave and say, yep, it's good without testing at first.
• 0:29
  I think that's a, a huge important thing for us technicians is I know we're busy. Trust me, I'm out here, you know working away too, but take that extra five, 10 minutes and double check your work that could save a call back. Just like that.
• 0:30
  Trevor: Yeah, no, I know I've, I've had many scenarios. I remember when I was in the field where.
• 0:31
  I've done a replacement and save it was a compressor on a condensing unit. I remember this one time it was, I think it was a, a two cylinder Copeland. I replaced the compressor was failed. So I put the new compressor in, I did all the checks. Then I, I, you know, ran the system, check the soup, read everything, look good.
• 0:32
  Great. You know, I got signed off. I left, I had to come back into the day of driving by the store to just to go drop in, check in on that because it was one of my customers and then I just look up it cause it was on, it was inside and inside, you know, on top of the walk in box and a suction line, the compressor was white.
• 0:33
  I'm like, what is going on? And cause it was early morning before the store closed. So I didn't check when the. The curtains were pulled down, you know, they added curtains to it and the curtains were pulled down. So the load's even lower on an open case. And that's what was a learning moment. Like you got to check after the, for your Subaru, you got to set it close to temperature.
• 0:34
  So if you're trying to get a say a 32 or zero degree temperature, you're going to be within a couple of degrees set in the Subaru. You can start, but as you get closer and closer to really fine tune that TX valve, you got to set it closer to the end. And then after a defrost. After the curtains are pulled down, all these different things that you need, you need to do.
• 0:35
  Cause if you don't, it's, you'll get caught. Like I did there.
• 0:36
  Andrew: Yeah. And those are the, those learning moments that you just, you, you will always remember. And trust me, I got plenty of those, you know, and working out in the field as long as I have. And, and you're, you're actually, you look back and you're thankful for those learning moments.
• 0:37
  At least I am, you know, I know it's, it's a pain when you're doing it, And trying to figure it out. But then you look back and he's like, man, I ran into this before in the next service call that has that same thing or that same issue. He's like, Oh, I know what's up. You go and you check it and you're like, yep, this is it.
• 0:38
  And now you just, now you're just killing it after, you know, so it's those, it's those important things in this trade that makes, make you stand out is, is learn from your mistakes and then, you know. That's, that's what we're doing, you know,
• 0:39
  Trevor: and then can consistently just putting the work in because you got to see something I said this time and time again, seven to 11 times.
• 0:40
  So if you're working, you're replacing a compressor, you're going to have to replace many, many of them to get it down. You know, it's not like you do your first one and you do one with one another guy and do one by yourself. It's still, if you don't do it for six or seven months. You know, then you're starting, it's kind of like you're starting over again sometimes.
• 0:41
  So the more you do it, the more you put the work in, you know, and same with electrical, you gotta be using your meter every day, you know, you might go weeks, which is all mechanical stuff and, you know, washing out cases or cleaning drains or cleaning condensers, but you gotta get that meter out. The more you get it out, the quicker you're going to learn and be better with electrical and controls for sure.
• 0:42
  Andrew: Yeah, exactly. That and reading a a ladder diagram. You gotta know how the ladder diagram works. If you know how to read your meter and what to expect, know how to read a wire diagram, if you can get those two skills. Yeah, you're, you're going to go far in this trade.
• 0:43
  Trevor: Yeah,
• 0:44
  Andrew: you're definitely going to go far in this trade.
• 0:45
  Trevor: There for sure, because I think that's one of the things that we, I think, I think that should be the first couple of years in, in trade school, or if you get it, you know, just electrical, because that's most of our, our work. Especially when you get into issue systems, right? Because now systems are all controls and stuff.
• 0:46
  Which leads me to one of the things we talked about earlier. You ran into a control problem, one of your stores, and you had to replace a few sensors, I believe. So why don't you talk about that story?
• 0:47
  Andrew: Yeah. So I had a call that it was a proof alarm for rack, I think it's an old Hussman rack, if I remember right.
• 0:48
  But either way so why don't you explain what a
• 0:49
  Trevor: proof, a proof alarm is for, for everybody out there? What is a
• 0:50
  Andrew: proof alarm is a, an alarm where the compressor should be on, but it doesn't sense that it's on. So I could have tripped out on oil. I mean, there's, there's many different reasons why a compressor stops and that's where our job is to come in and figure out why do we have a proof alarm on this compressor when it should have been running?
• 0:51
  So then you go and you check all your things and make sure that it's running. And then of course, when you're there, it wants to work fine. So now you got a really fine tune, like what's going on with this compressor. So I start cycling it on and off, trying to get it to do. This proof alarm and I finally figured it out.
• 0:52
  Well, you get, of course I pull up the wire diagram, look at everything and how it's controlled and what turns it on, what turns it off, what safeties it has as a going through it. And so I start using my meter and verifying things that all of a sudden this thing stops working. And I'm like, okay, now I can figure it out.
• 0:53
  So I grabbed my meter, start going across it. And I actually found out that I have an old contoured. One of the board points has failed and it's either sticking close or sticking open. And that's, what's causing the proof fail or this random occurrence. So I finally figured it out. Now, if you're lucky, you could actually just change the board point to a different point on the board and let it rip.
• 0:54
  I wasn't so lucky. So I had to change out a whole control board and I thought I was a really good idea to do it live so I don't have to shut down the rack. That was not the right move there. I ended up shorting it out and that short ended up frying the the high pressure safety control. And I shorted out the compressor module for a Copeland compressor.
• 0:55
  Lesson learned, right? So I go in and change the board out. Now this time it has no power. So I just hurried up, flapped it on, turned the rack back on. And I go and verify that, that board points working. Well, it's not working. So I go and check the wire diagram and go across these points. And sure enough, I'm like, Oh, it's a high pressure.
• 0:56
  So I bypass the high pressure still not working, but I go and Ohm out the high pressure control. I'm like, man, it's now it's good. So then I grabbed my meter again and start going down the line. Up Scotch. And I think that's what they call it. And all of a sudden I found it that I'm missing it between my M1 and M2 on my compressor module.
• 0:57
  So I go and bypass. Was
• 0:58
  Trevor: it a Copeland? Was it a Syntronix?
• 0:59
  Andrew: Yeah, it's a, it's not a, it's not the oil pressure safety. It's the you know the sensor module that senses the
• 1:00
  Trevor: heat. Yeah. I forget. Yeah. It's a CRI 1 on the older ones. This is a CRI 1. Usually INT69 or something.
• 1:01
  Andrew: Yeah. I think so. But it just senses.
• 1:02
  Yes. Motor protector. It just senses the compressor, the temperature of it. Yeah. Needless to say, M1 and M2 was popped open. So I bypassed it. So then I got it up and running again, however, can't leave it that way. So you got to replace what, well, unfortunately what I fried. So I go in and replace it and then everything's working groovy now.
• 1:03
  But you know, those are the, those are the, what the, the important part is, is understanding the wire diagram that you have following it. And then using your meter to know, like, if this is, if you got a contacts, that's close, what voltage should you read? You know? And then if it's open, what voltage should you read?
• 1:04
  Those are the most important parts of diagnosing electrical failures or anything electrical is knowing what you have and what you're supposed to have. Cause if you don't know what you're supposed to have, that's kind of a hard scenario of like, is that good? Is that bad? I don't know. So it's important to know what you're supposed to have.
• 1:05
  Trevor: Yeah. So, so basically you went in, you checked it, the, the biggest thing is, is that it happened while you were there. Cause sometimes this doesn't happen while you're there. So you're able to catch it where that board point that wasn't that contactor wasn't making. And what, what was that actually connected to again, that board point,
• 1:06
  Andrew: the board point is connected to the control.
• 1:07
  So the control says, Hey, I need compressor two to start up. Or compressor three or whatever it is. So it says turn it, turn, turn on, you know, and that's just controlled by I think it's trying to maintain suction pressure. So as soon as pressure goes above set point, it turns the compressor on. It's set point pulls down a little further shuts compressor off or.
• 1:08
  Well, in this case, that's what they have. This one, this rack doesn't have an unloader or, or a BFD. So,
• 1:09
  Trevor: and so then, so you caught it while you're there, which is good. You recognize with your beater that, that, that point is sticking, not working. You switch over to an another point or another board altogether.
• 1:10
  Cause you had to get a whole nother board. Is that correct?
• 1:11
  Andrew: Yeah, I had to swap the whole entire board out because I didn't have an extra point on that board. But if I did, I would have just swapped the board points. But however, I just, like I said, I didn't have an extra point, so I'll had to switch the whole board.
• 1:12
  Trevor: Yeah. And so then you have to re reset up the, the new board, right. With the addressing. So that's super important. Those things, right. The easy thing is, is that you can just look at the old board and, you know, move all the dip switches that are, if there's dip switches on there to the correct positions, if you have them, but you want to really.
• 1:13
  If you want to be good at it, you got to understand all the dip switches. Don't just look at a change of this switches. You're going to do that for sure. Take a picture of the old one or have the new old one there, but you really want to know when you're switching a dish, which, what does that actually do?
• 1:14
  That's the key thing, right? Yes. And so then I said, then you switch it over, then you ran into a few more issues. Once again, sort of those out with your meter going along the wiring diagram and not going to ground, right. Going across, like, that's the big thing, right? Like kind of, like you said, the hopscotching, that's, that's the way to do it.
• 1:15
  Cause when you're, if you're using two 30 volts, two or eight, two 30 volts, and you go to ground, you're going to, you're not going to be able to troubleshoot it at all. You know, that's a safety.
• 1:16
  Andrew: Yeah, absolutely. Yeah you, when you're trying to troubleshoot electrically, you always go across. Whatever you're trying to do, if it's a contact or if it's a motor winding going to ground, the only thing that does as voltage wise, going to ground that only is going to protect you.
• 1:17
  If you get shocked, that's it. There's nothing else there. I, especially like you said, Trevor, if you're using two eight or two 40 volt, you got two sides of power. You got one side power going one way. You got another side of power going the other way. You're always going to get one 20 to ground. In most circumstances, I mean, there is some really crazy scenarios where you can get zero, but for the most part, you're going to have one 20, the ground at all times.
• 1:18
  Trevor: Yeah. And so this is the thing is you got to do this more and more. Like it's not the first time you use your meter on controls. You know, the thing is, is though, when you get in that situation and I know how you feel, you got there and you're like, okay, we found this board point on it. And then there's no more board points.
• 1:19
  Oh, yes. Now I need to go get another board to do this. So, and, but that's a part of our job, right? Finding that stuff and solving the problem for the customer. And I know you sent me a video maybe two weeks ago now about a condenser fan. I thought that was pretty cool. Yeah. Into the condenser fan.
• 1:20
  Yeah,
• 1:21
  Andrew: this, this one's crazy. I've, I've came across this probably twice in my career. One, when I was just starting out to just, like I said, or like you said, two weeks ago, but I had this unit that popped a breaker or excuse me, popped a fuse. So you go and own everything out. There is some power issues and we're starting to get some crazy weather over here, so I'm like, maybe it just.
• 1:22
  Right. It's so I always double check, check things, make sure that we're, we have homes across L one L two, you know, L three, make sure we are just not shorted, nothing to ground. I check all those things. Everything's good. I'm like, okay, it's probably just, you know, the weather related slap, some fuses in there, pops it right away.
• 1:23
  So I'm like, well, there's obviously something going on. Well, not right away, shortly, real quick. After I turned the disconnect on it, it just pops. Okay. Something's going on. So I start checking things still. I'm not reading anything. So then I start isolating the major components. So like a compressor, condenser fans, evaporator fans, electric defrost.
• 1:24
  So I start isolating which one's what, so I could figure out what's going on. So needless to say I isolate the compressor and turn everything on. Few moments later, pops again, I'm like, man, there's something really weird going on. So I hook up the compressor again, and then I take out the one of the condenser fans.
• 1:25
  And what I ended up doing was ohming out the condenser fan. I had three ohms on it across the legs. Okay. That's good. And then I checked the other condenser fan. Now I got 36 Ohms or something real crazy, just different. And they're the exact same fan model. Okay. Something's weird. Something's going on. So what I ended up doing was I ended up spinning.
• 1:26
  The condenser fan motor ever so slowly. You can't just spin it as fast as you can just barely have it spin. And then I have my meter hooked up still to those two wires. And all of a sudden it'll just go down to zero Ohms and then it'll go back to 36 and then the zero Ohms and then 36. And then, you know, full on full cycle.
• 1:27
  So what I did was I isolate that condenser fan. Put the other fan back on, fire it up and everything started working just fine. Other than that, could answer fan, but that, that is a crazy scenario. And I, like I said, I've only came across that twice in my whole career. But yeah, it's out there and. Doing what I did was the, with the meter, you got to know what you're supposed to have.
• 1:28
  And as soon as it said zero, zero from one to one, two, I know that's, that's where my fault is knowing that that's how I knew that I had a bad motor, but as that rotor would spin, it would finally touch that certain point in that wire and that causes it to short out, but yeah.
• 1:29
  Trevor: And that's an interesting one because that takes time.
• 1:30
  Cause sometimes you don't. You know, you go through a lot of fuses and some people have like a little breakers there to trip the fuse fuse breaks. I can't remember what they were called, but they would, I seen lots of people use those, I just use fuses myself too, but you go through quite a few sometimes.
• 1:31
  I remember going through quite a few fuses to figure out a problem because it only happened at one time in one exact scenario, kind of similar to that. Right.
• 1:32
  Andrew: Yeah, yeah. It's just, it's one of those crazy calls that you just, like I said, you don't forget because it's not, it's not black and white, but it's black and white.
• 1:33
  You know, you go across the motor at zero ohms. Oh yeah, that's, that's my problem. It's real simple. It's real easy. It's those ones that you are shaking your head and pulling your hair out if you have it, you know, you're just trying to figure out what in the world is going on. And those are those, like we talked about those learning moments that you just never forget.
• 1:34
  And it's, it's cool to come across that again, because now I, I mean, I couldn't tell you it's been too long that first time, but I know I was blowing fuses left and right until I finally figured that sucker out. But I learned the process of elimination, so on and so forth. And then of course, spinning that motor, that's because my old, cause I ran across it once before and boom, there it is.
• 1:35
  Trevor: And that's it. And once again, it's, you got to do all this stuff safe, just like Andrew's doing it, systems off, lockout, tag out, you know, things like that. Just make sure that you're being safe out there while you're using it. Cause we are in an industry where we're doing with high voltage and low voltage and chemicals and refrigerants and oil.
• 1:36
  So once again, it's super. Super important to be safe out there. Andrew, I want to thank you for taking the time just to have a quick chat on some of these service calls you took, because I think it's important for other technicians here, because I know there's a lot of other technicians that, you know, we struggle with similar things.
• 1:37
  And it's important to, to talk about it and learn from each other to, to really gain that knowledge because you'll continue to come across things that you may have not seen before. But this is good because this means you're learning. You're getting out there more. You're putting the work in there.
• 1:38
  You're not just going changing filters or changing belts. You're going in and learning each time, taking more service calls, taking on call to get better. And I think that's how you you get better. The fastest is taking more calls.
• 1:39
  Andrew: Absolutely. And don't be afraid, you know, if it's, if you're getting called out on a service call and it's not working, what's the worst you can do?
• 1:40
  Make it not work anymore. You know what I mean? So just, just don't be afraid and just get your hands dirty, get in there and figure it out safely. Of course, like you said but I, I definitely feel, feel like if you go out there and you take these calls, you're just going to get that much better, that much quicker.
• 1:41
  And. And don't be afraid. I know it's sometimes it is, it's tricky like that, but whatever you do, just do it safely. And if you break it more, it could be replaced, you know, it's just, and it's part of the trade. It's just, I don't know. That's, I guess that's what I tell all my apprentices is that don't be afraid to break it.
• 1:42
  Because it's already broke anyway. So what's the worst can happen. And I, I rather you see you try out there and get it. And then, you know, within an hour. Let's say you're still out there. You still don't know what's going on. Give your lead a call. Give you whoever a call, you know, your mentor or whoever it is.
• 1:43
  And then that they'll help you through it, you know, and that's, that's what I tell my guys here is I've always preaching. I'm like, take any call you're going to learn and we'll, we'll make it through it.
• 1:44
  Trevor: Yeah. Oh, I love that. Andrew, I want to thank you so much. And we'll do this again.
• 1:45
  Andrew: Perfect. Sounds great, Trevor. Thank you.