This video is brought to you by spore'ln quality, integrity and tradition. Today's service call is on a walk-in cooler, that's not working properly. The complaint is, is that the temps are high. This system is actually a like a hybrid, medium low temp and they run like 20 degree box temp inside of here, so jump up onto the roof.

We've obviously got nothing going on here and see what's going on so walked up to my unit. I went ahead and pulled the cover off nothing's running at the moment. First things I want to check is you know if condenser families are locked up, they don't seem like they are depressors, not hot. It's just worrisome.

We're gon na have to put some service gauges on this guy defrost clock without gon na meet her out is in refrigeration mode, so we're going to get some gauges on this guy and then troubleshoot further, so my pressures are equalized out on the system. So at this point we need to check the compressor contact or just knowing the sequence of operation to see if we've got coil voltage going to it on this particular system, the power should go through the low pressure control. The high pressure control, which I ran in series and then go directly to my compressor contactor. This is a basic pump down system.

First, we're going to measure three-phase power coming in make sure we got three should be a 208 volt circuit. So to 3 we have three-phase power coming in, let's measure across our coil and we've got 208 bolts going through our coil, and it's indicating that we have an open coil on the contactor. So it looks like we have a bad compressor, contactor we're going to get that contact to replace and then troubleshoot further from there, but power down the unit. Okay, let's double check power to make sure we're powered down before I stick my hands and yeah dad.

You always want to check the ground yeah, so the system's completely de-energized go ahead and replace this contactor. The new contactor comes with the coil on the bottom, so I got to rotate this around. I've shown this a million times, I'm driving that's of the writings upside down kind of make a mental note or take a picture of the wiring and try to do it wire for wire. This one looks pretty tight, so I'm probably gon na have to disconnect some stuff.

So it looks like our it's. The phase rotation actually doesn't matter on this guy because it's a pressors so everything's back and installed and we're gon na turn it on and see what happens short cycling. That's not good! Why are we short cycle notice that on off on off on off something's funky? In there probably a pressure control issue, so what we need to do is look at our service gauges or parabola. We need to see what happens while it's short cycling like that, our pressures.

Look fine so something's wrong there, it's more than likely going to be an issue and a pressure control, because I've got the right contactor and what we can do test across the coil voltage and see what we get see, how we're getting that funky on/off on/off reading. That's indicating to me that we've got a pressure, control failure somewhere. I'm gon na take a hunch because of where we're at it's really really hot, that it's the high-pressure control that has failed in order to test that we can just bypass the pressure control and let the system right powers off. We cut this guy right here.

Why are not these two wires together and see if we still have the same issue? It could also be the I see, there's a high temperature limit switch to right here. So it could be that too, okay high pressure controls taken out of the picture. Let's turn it on and see what happens, but that compressor sounds really healthy. Sounds like an internal bypass on the compressor right now, so the compressor has the proper voltage, but it's making a god-awful sound hot dish.

Actually warm discharge line, lukewarm suction line. Now the Box temp is really high, but we shouldn't be that's a that's a bypass. This is a bad compressor. The compressor is so hot, it's ridiculous and it's not even the hot outside right now, it's probably ninety degrees and our liquid saturation temperature is way too low for 90-degree ambient.

You should have about 120 degree, liquid saturation temperature, so what's happening is the discharge valve in the compressor? Is bad or the read is bad or something so this looks like it's going to turn out to be a cluster F, but we're gon na have to change a compressor. I'm gon na have to get a hold of the the higher-ups of this particular restaurant. Make sure they want me to do this right now, which I'm sure they do, we kind of have it all clear to go ahead with any major repairs like this, but still the other thing is we don't know what caused that content or that a compressor to Fail so it's gon na be hot and sunny today, even though it's cloudy and overcast right now, so I put up my easy off. The problem is: there's not enough room with this exhaust fan so anything's better than nothing.

It's not blowing the top off of it. So it would give me some shade at this point: we're gon na go and recover. I went ahead and hooked up to the receiver for the high side, my suction Schrader, for whatever reason I can't get it to come out, so we're gon na have to pull it through the Schrader on the suction side. But we got an open port on the receiver and I'll go ahead and disconnect the coil voltage to the compressor, contactor and turn the system on, because I think this is an electric defrost system.

I do need to confirm that and if that's the case the when the unit's powered down it turns off the cylindre valve. So by disconnecting the coil to the compressor contactor, I can open the cylinder valve. The system would be calling and will get better with Bridger and flow through the system, so I've got a tank here. That already has some.

We got a watch too total charge of the system, because this tank can only take 18,000 same time. I know the system doesn't take on a smaller system like this. I don't mind phone, it's not going to take that long to recover it really really hot. I might hook up the abdominal got some abundantly.

His tank is leaking. Look at this when I open it up, it's leaking out the Dow, like that the cats and I push on this - that sucks. Well, I got another empty in my truck I'll have to go, get it sometimes these recovery tanks are so cheap man that pisses me off all right. So let's try this again now my supply house.

If the tank comes with classes that we've been about you, so I've explained this a million times I like to hook up to the vague report and my scale and I'll see, grow it out. Okay, so it's zeroed out that way. It counts right here on the recovery machine, the inlet open up my side on my lower side of my agents. The trial is only see without my scale again let it countdown they go, get a thing for my hand like salt oil, all over myself.

Don't let it push into the recovery cylinder? I haven't even turned on the recovery machine, yet we're waiting okay. So it's pushed all the gas in it pushed in about a pound. Now, I'm gon na turn the recovery machine on let a pump. I also got a disconnect my coil voltage and in order to disconnect the court, the voltage I'm just going to pull this jumper off right here, make sure it's safely out of the way turn it on and now my coil should be energized, while it's recovering I'm Gon na go ahead and start sanding up the compressor and getting it ready to be replaced, stand-up the fittings and everything I expected this system to have more than four pounds: four and a half five pounds of gas.

I expected it to have about nine pounds, so we're gon na make sure that this unit doesn't have leaks. We're pulled into a negative 4, but we're gon na shut it off at that, because I don't want to pull any more air into the system if it does have leaks, so we're gon na leave it at that and then go ahead and put all the recovery Equipment away and then get started on changing the compressor. I got the new compressor right here and we'll get started on getting that replaced. So when I need to bring my whole van on the roof, it's kind of nice to have this cook.

This hook is made by Cline and it's got a swivel on the top and it's really easy because you can, you know I got brought my vacuum pump up and then I also keep a carabiner a large carabiner. On the other end of my rope - and I have about a 75 foot rope so that we can get about some big roofs and this way, if I'm bringing up a lot of stuff, I can shackle something and then hook something and then sometimes I can like Right now I swung that hook down and hooked it on to that come up here. So that way I can keep doing that. So it's nice to have a rope.

That's prepared for you, a nice big, thick rope, this guy, it's really humid and bugs I'm worried about moisture contamination, we're gon na start by doing things. I still have the system energized, I'm gon na. Do it until the last minute, I'm a little lazy and don't work? What we're gon na go ahead and replace both of these pressure controls and put on a dual pressure, so I'm gon na power down for a man there's connection across the beads disconnect the crank case here, which is energized like dump chambers. Let's go disconnect.

Remember I already checked the disconnect that it works, even though I have the coil voltage for the contactor disconnect I'm gon na tape up these leads there's no chance of them shorting out or something happening. That way, I can still always good to be sure. We've done without pressure control, some cutting and crap out it's hard for me, but I'm trying to put my tools away as I go. I usually have a giant mess up here, want to make sure we first like the oil all in the unbraced suction, because there's not a lot of room.

If I get a flame out there, so we got a budge like that. So now there's a buying on it might even pop out on its own. No but holders fly out mind you were still pushing to nitrogen, get this guy pulled out. Anyone set in and won't open the plugs until we pipe it or get it ready.

You're lifting these style of compressors stick a screwdriver through the lip port right there I'll help you to do everything. We're gon na have to check the oil on that compressed. It's not severely low discharge valve. You go bad ugly.

We're gon na fix all this. This is NASA we're also going to change both of those condenser fan motors to go in cut know we want more yeah won't cut very back up, like I said we're gon na do everything we can before we open up the compressor to that moist outside air. That way, it's open to atmospheric with the least amount of time because, like I said really all right, so we're going to try to prep everything. Get it ready, got some copper here.

We're going to use to redo stop with straight as possible, bender just kind of guesstimating where to bend it, making a little long, we'll clean it up once I need it. Stop right. There use the marker when you're doing to be bending kind of mark where you want to cut it. I say we're gon na bend it about right there.

That's my mark for my vendor all right here on my band. There it's a little mark and that's where my hand is going to be line that up to that mark band and then it's bent where I need it to be and proceed with what we're doing here then it's about right. There need to getting this tape. Often here run amok in this, where I think it's going to plenty of room here again using my to be bender, bend it down and walk.

Things looks like going to work perfect stretch a little off, but I can fix it and mock up the liquid dryer and all open russer embrace it in best friend be careful with the cyclases there copper coated steel is given a scuff. That's all remember what I said learned: how not to react. There's oil in there and it's hot if I tipped it over, I'm going to pour it out and possibly ignite it on the roof, so I'll be ready for that stuff. Dryer will go like that.

Cyclops, to make about a 45 degree fitting here not like that, my ball games, okay or again, wherever in cicadas, outside worried about the site class. So I need to get it cooled off, quick and then I'll finish. The braising and I'm gon na definitely inspect every one of my. I forgot one like what they're taking all this stuff off, be careful with it really so we're at about 12 minutes.

We've changed one psi, I'm not too worried about it. I'm gon na do a leak check on it on my welds and then we'll we'll continue with everything. So I sprayed some big blue on all of my song and my braised joints. I don't see anything everything's, looking good, no clusters of bubbles or anything yeah everything's.

Looking cool so we're gon na go ahead and proceed with finishing this up and get the vacuum pump running and then we'll worry about electrical and I'm gon na change fan motors and stuff. The vacuum is doing good still going strong 700 microns, I'm starting to run the electrical pressure. Control right here, crank a a cedar going down through there all wire everything in I just got to pulled out for now. Now I'm gon na go out and do the fan motors too, and they will wire those in and keep on going.

I don't use these very often, but when you need them, they really come in handy for getting into these things, especially when some, when these blades some manufacturers put them on backwards, where the hub's going towards the motor - and it's like almost impossible to get your normal Allen wrench: I carry a tiny allen, wrench for a condenser fan loaders and I got bigger ones in the truck. I just finished cleaning up the electrical. I still got a zip-tie some stuff and clean it up. It's de-energized right now.

What we're doing is this is the line voltage on the top of the contactor, we're coming off a line to going directly to the compressor, contactor coil to one side, so one side of that compressor, contactor is always energized. The other side is coming off of line. Three and it's running through our pressure control all the way over here to that dual pressure control. It runs through the dual pressure control as long as the low side isn't open.

As long as the the low side is closed and the high side is not open, then power will come back and energize the the other side of the contactor coil. What happens is, is this unit does have electric defrost, so the time clock gets power and sends it downstairs on the number four terminal runs through the temperature controller and then comes back up or runs through the temp control turns on the solenoid valve, and then the System turns on and off via the pressure control. So that's what turns this contactor on and off, and then we have a crankcase heater up here and then condenser fan motor wiring on the bottom. So that's alright, I'm still cleaning stuff up.

I still got to remove this and then set the time on the defrost clock, so I still have the compressor disconnected, but I bump started the condenser fan motors to check the rotation they're going in the right rotation we're just about where we need to be on Our microns and we'll do a decay test, but everything's looking good so far, we'll go ahead and get ready to hook this compressor up and then yeah, I'm just still cleaning up, but pretty much the unit's all ready to go and ready to start up. While I'm waiting for the vacuum to finish, we're going to go ahead and pour out the oil out of this compressor and see if we're low on oil charge. Just because when I was cutting some of the lines I had some oil blowing out so we'll just do a quick test. You didn't have a bearing failure, so I would expect the bank failure.

So the first thing we're gon na do is weigh our pan. Just so, we know how much it weighs 2 pounds 3.5 ounces, I'm going to mark that down and then we'll continue on never gon na get all the oil out, but this thing looks like it has plenty of oil, so this compressor is supposed to have 45 Ounces of oil in it I pulled out 35 ounces. I'm gon na call that good, I'm not worried about the few ounces of oil that are missing. There's still oil in that compressor and then also there's a little bit traveling through the system.

But that should be fine, nothing to worry me, so we held a good vacuum. I'm currently charging the unit. The unit currently has about four pounds of gas in it. That's what I pulled out so we're gon na start it up with that and then feel charged from there.

This unit does have a head pressure control valve, so we got to make sure we put the right amount of refrigerant in there for that. With this particular system, we can just weigh in the total charge, but I want to see where the sightglass clear is that and then we'll add whatever else we need to now's the moment. What happened to run for a few minutes, this unit should have a fan delay on the evaporator cyclases flashy. We want to give it a minute before we add gas, we don't want to overload this compressor.

It's under a really heavy load right now. The r-la on the compressor is about nine amps and then right on the top. It says operating max ten amps, so we're just going to watch it. It's running right now we're at 7 amps we're, definitely still low uncharged.

We're slowly going to charge it, but we just don't want to overload this guy with with the refrigerant and they get go off on overload. Basically, so we're just going to slowly charge it. I'm telling you this box is 90 degrees, so it's gon na take a long time, so we're gon na slowly do this. Another way you could do it is.

You can also fill otolith suction valve kind of like a CPR valve, so we're just gon na slowly charge this thing and watch it come down in town. It's currently about a hundred and eleven out here. So I'd expect my saturation temperature to be about 20 over ambient being that it's a microchannel condenser and that's just a rule of thumb so with us having but again we're we're still flashing, so we don't have a whole charge in our system. Yet so one hundred and twelve we're about on with our saturation ten but with but again we got to clear the sight glass though so I'm just doing it slowly.

So it's been a while. The box is coming down intent, but it is taken a long time. We're at about fifty five degrees right now, I'm a little worried about how slow it's coming down the expansion valve is not frosting up. It looks like it's feeding properly, but I will say that the distribution tubes coming out of the expansion valve are frosting out, but the coil is not frost, you know currently 55 degrees in the box or superheat is high.

I may go down there and try to adjust on that valve a little bit, but we'll see 52 psi. We do have a pretty low suction. The saturation tempest is kind of low for the Box down. But again it's it's going crazy right now trying to come down my head pressures still pretty good on point yeah, so we're just watching it.

This is my bow and the distribution tubes are frosting up. I did confirm, though, that is a pressure within any expansion valve. So that could be part of the problem. I am going to go ahead and try to it pull that strainer and check, and also yeah something's up with this valve someone's been wrenching on it.

It is basically brought out as much as max the dog should be sitting in the mid position, so I can't open it someone's been drinking. I don't know if I have a pressure limiting power. This is a quarter that kind of required pressure limiting, but I definitely want reinstall. This coil many years ago needs to get kicked in the head because they didn't give you anywhere Mountain sensing, woman, there's really nothing I could do.

I got to put it back in the same place, but I ended up changing the power and stranor it's clean. So now we're gon na do is we're gon na reset the superheat spring. So it's maxed all the way out. So we're going to do is count.

How many turns it is to go all the way in and come back out halfway and that'll be what the valve would come, what a difference? We've got suction pressure now so yeah power head was the issue and there was a pressure limiting one in there. I didn't have that, so I just put a normal low temp and what I'm gon na do is adjust the defrost. So the defrost doesn't happen is his long evaporation, so the Box temp doesn't get so high. The fear is, is that coming out of defrost, because that's kind of like a hybrid freezer, they only get it down to 20 degrees so and it still does Electric defrost.

So the fear is, is that with the electric defrost, the Box temp is going to get too high. Unlike the beer walkin that I did a while back where they maintain 35, this one they actually maintain 20 degrees. So there's a legit reason to have a freezer boil, but yeah we're looking good we're not over amping on our compressor, we're still flashing on the site glass. So I'm gon na.

Let it run for a few more minutes and we might top off the charge a little bit more and we're just. It looks like our box. Temp is 48 degrees right now and drop in they're, gon na say huge and super meets 24 degrees down at the evaporator. So it's gon na be a little bit, but you should see a huge difference now.

It's amazing: what happens when your expansion belts working right, so we've got 17 degrees, evaporator superheat, i'm not going to adjust on it. Yet I brought my box temp down to 35 degrees, so we've dropped like 15 degrees. In like five minutes, it's kicking ass. Now our suction pressure, you know anytime you're working on a system.

You need to understand what your suction pressure should be and what your head pressure should be. You can use your rules of thumb and that will get you in the ballpark. Okay, the evaporator TD, approximately on this particular system, should be about 10 degrees, so my evaporator saturated temp is 25 degrees and my box temp is 35 degrees. I have a 10 degree TD, that's about so you can predict if you have a 35 degree box temp.

Your saturation temperature be about 10 degrees below that on a walk, and now you know things can change. If the system was designed, funky or something that's just a rule of thumb and then as far as your head pressure, this is a microchannel condenser. They usually run about 20 degrees over ambient, so condensing temp of arabia' CTO a approximately 20 degrees over ambient. If this was a tube and fin condenser, I would expect it to be about 25 to 30 degrees over ambient.

So that means that my ambient temp of 112 degrees - I should add about 20 degrees of that so 120 to 130. To look at that. We have a hundred and thirty five degree liquid saturation temperature - that's pretty accurate, so it's about 23 degrees. You know something like that somewhere in there 23 degrees over ambient.

That's about accurate okay. Now, again, those are rules of thumb. You can't just do that and move on you've got to look at everything so the entire time, while I'm working, I had an amp clamp on my compressor windings. When I fixed that expansion valve and started it up, I'm watching my sight glass.

It makes a little more sense to because the factory charge on this set. It was 9 pounds and originally I had put about 5 pounds and I cleared the sight glass, but when I fixed that expansion valves power head all of a sudden, I was flashing. So I put 2 more pounds in it now. My sight glass is clear.

I still have to account for my head pressure control valve, but again I'm being leery of adding extra refrigerant at this time, just because it's so hot outside - and I don't want to overcharge this unit at the moment, so we're just watching it come down in temp Monitoring the box temp it's kind of going in and out right now, because I'm quite a ways away from the walk-in, but still the field piece probes are connected, so we're 34 degree box temp we're set for about 20 degrees. So that's really good superheat. We really don't want to start wrenching on the expansion valve until we're within about 5 degrees of set temp. So once we get to about 25 degrees box temp, then I would expect my superheat to fall in line.

I must expect that superheat to be about 8 to 10 degrees, superheat very important that when you're done with a system like this, where you're worried about it being overcharged that you pump it make sure that it comes down effortlessly. So this one was running around 390 head pressure and I pumped it down. It went up to about 403 and then it stopped so that to me tells me that we're fine and we're not overcharged. So this box kind of hit a brick wall, which I expect it to it's sitting right around 35 30 degrees.

It's gon na take a little while my super heat kind of calm down my super heat. Basically, I can't remember where was running last 14 degrees or something like that, so we're just gon na let the Box stabilize out tell them to keep an eye on it. We'll probably come back because they have a nice thing that has a bad condenser fan motor. So we're gon na be back by tomorrow.

Get that going follow up on this guy make sure it's down to temp and everything. It's got a take, walk cuz! You remember that box has been. Oh, I didn't tell you guys where the box has been down for three days, so you know it was. It was probably over a hundred, I said nine here it was probably over a hundred in there.

So it's expected that it's taking a long time put this back together. So I came back down here to do a follow-up superheats a little bit low box. Temp is a little bit low. They want to maintain about 30 degrees in here, so we're gon na adjust the box temp and we're gon na increase that superheat a little bit because it's running a little bit low at one degree the coiled looking good, no frosting problems, everything straight with that.

There is a fan motor going bad, I'm probably going to change that, because I just want this to be done. Oh yeah, so we're going to increase the superheat shouldn't be hard at all. There you go just about a half a turn to raise the super heat on this guy and we'll see what happened. That's a little bit better.

It didn't take much. It really doesn't take much for a superheated justment on one of these valves, and you really got to give it time to accept that adjustment and stabilize out so I'm not going to twist on this valve anymore, even though I'd like to see a little bit closer To six to eight we're gon na leave Abby at nine and mind you, that's not always going to stay at nine. It's gon na! It's gon na you know range a little bit as the court has the dollar within closes, so we're good to go. I'm gon na go ahead and look into change in that voter see what we got ta do to do that much better now that it's not making that very noise, so yeah we're good to go.

We're gon na just double check on the defrost and then wrap this one up all right, so this was another call that led to one thing that led to another. Okay, looking at the big picture, we tend to run into these things like this all the time it seems like. So we had a service call on a walking cooler. It's it's kind of hard to call it a walk-in cooler because, like I said it's a hybrid walking core, they run it at about 28 degrees.

Fahrenheit is the temperature they maintain inside this box. So it's not necessarily a walk-in freezer per se, because, most of the time walk-in freezers are at zero or negative 10 somewhere in there. But anyways we had a service call on a walk-in cooler that wasn't working properly. I found that the you know had a bad compressor contactor the coil was open.

Okay, once I replaced the compressor contact where I noticed that it was immediately short, cycling, on/off on/off. I had a hunch because of how hot it was that there was a problem with the high-pressure control, so I bypassed the high-pressure control and the problem went away. The short cycling issue, so we confirmed that the high pressure control was the issue once I went ahead and started the system up without the high pressure control, I noticed that the compressor was making a horrible sound coming from the valves inside the compressor. It was bypassing internally as what was happening, so the compressor has an internal pressure relief and that pressure relief was bad.

More than likely what caused this all was high temperatures, and I made an assumption to think that maybe a condenser fan motor was failing or something because the condenser wasn't dirty. I know I didn't show that in the video, but something caused the the discharge valve or the pressure relief within the the compressor itself to fail, and that was probably a high-pressure issue. So that's why I changed the condenser fan motors. At the same time, so we went ahead and replaced the compressor contactor, both condenser fan motors, the compressor, and then we put a new dual pressure control after I started the system back up.

I noticed that we were running a very low suction pressure and found that the expansion valve was not working prop. So I went ahead and changed the powerhead on the expansion valve and then I also found that someone had been wrenching on the superheat adjustment screw on the expansion valve and it was basically backed all the way out to to drop the superheat as low as possible. That's not good either, because expansion valve shouldn't be maxed one way or the other. They typically sit in the mid seated position, so went ahead and set that back into the mid seated position.

Let the unit run for the rest of the night came back out. The next day found that the superheat was a little bit low, so adjusted it a little bit higher got it to about nine degrees, which you know. I'd have been a little bit happier with. You know six to eight degrees somewhere in there, but I wasn't gon na fuss too much with it and then I also changed that evaporator fan motor that had two screaming bearings in it.

So this definitely was a multiple. You know issues on this service call, but it's just. This is how it goes. Okay, like I said when we're looking at the big picture, we tend to find problems like this.

Okay customer was happy that call it's been about. It was earlier this week, so it's been about four days. Customer everything's been going great yeah and that's pretty much. It really appreciate you guys taking the time to watch these videos.

I really really appreciate the feedback you guys leave. If you don't already know, please leave me some feedback down in the YouTube comments. Send me an email to HVAC our videos at gmail.com with any questions and that's pretty much it. I really appreciate it and we will catch you guys on the next one.

Okay.