This video is brought to you by sportlin quality, integrity and tradition, so we have a call on a walk-in cooler that has a fan motor, not working, but it's more than that, because the evaporative coil is completely iced up, and so is this one right here. This is newer equipment um. I bet you. Any customers are leaving the doors open and the reason why i say that is when you come over here, i just walked in they just opened.

This door is propped open like that walk-in freezer. Well, that's probably gon na be iced up too all right. So what we're gon na do is we're. Gon na go shut the condensing unit off um.

We obviously got to get to the bottom of that motor, but then we got to figure out why it's iced up. I doubt that the motor would cause both the coils to ice up like that, but we'll see, i bet you they're leaving doors open would be my thought, but i'm going to turn off the condensing unit, let just the fans run while i'm doing that and then Get all my hoses and everything to get this thing fully defrosted, all right, my condensing! It's right here not going to tell you much. The sight glass is flashing, but the coils are iced up. So you can't trust what the sight glass says when you have iced up evaporator coils, you have to defrost it first and then attack the problem after so kill that guy and then uh, we'll figure out what's up condenser coil is not too bad.

This is the one uh yeah again i did this one back in april of 21 was the install on this equipment. So all right, i got this. Coil turned off we're gon na disassemble it we have two evaporator coils. We have this one, which is the primary, and we have that one which is the secondary okay.

This one has the temperature controller and this one right here controls a solenoid valve in this coil and in that coil, and then we have wiring running from this temperature controller over to that one that energizes the solenoid coil and turns the fans onto high speed and Low speed these fans cycle on high and low, depending on when it's calling for cooling uh, it's an energy saving feature, but it can also be problematic when it comes to defrosting, because every time it goes into defaults, it only runs them on low speed. Alright. So i'm leaving that one running while we're working on this one, it's a separate breaker that way that one can kind of air defrost. While i'm defrosting this one with water.

You always want to judge the ice by the frost pattern. Okay um to me this looks like it's been defrosting, but it hasn't been defrosting long enough because of a serious freeze up now um. I have a feeling this has to do with the temperature controller, which has the defrost built in, and it's probably um, not defrosting enough. Now, that's not saying anything bad about the control, because these things are never meant to be iced up this much.

This is caused by either it continually running and running and running and running, or the evaporator being completely plugged up and dirty um. I have a feeling again that they're leaving doors open, which is a common problem here, so we're going to get this defrost. But the point i wanted to make is you always want to pay attention to how it's frozen up and if you're, calling to get tech, support and things like that, always let the person you're calling know you know it's looks like it's three quarters of the way Down the coil or something like that, okay, my thought is, is that this unit goes into defrost. It starts defrosting, but then it doesn't run long enough, so it continues to turn on and then just keep freezing so we'll see i'm using hot water.

I was lucky to have it. I personally find that heat guns and torches can potentially damage the system by melting wires and things like that, and i find that hot water is the fastest thing to melt ice. You just got to watch to make sure it doesn't overflow the drain pan, you don't just keep going and making a mess inside the box unless that's what the customer wants. So i start at the top and just slowly defrost from the top and not worried about the bottom.

Yet because the hot water from the top is going to roll down right, so we're going to try to be as efficient as possible. But then the drain pan is getting full, so we're gon na stop and let it catch up and drain and then we'll start again. So it's a process. It takes time, but you just got ta, give it that time and be thorough with it.

A lot of people say that when they use water they make the biggest messes in the world. There's ways you can mitigate those messes. Okay, one of the biggest ways is, i typically do not apply water to the back of the coil. I'm gon na do everything to the front of the coil.

If it's just ice, the steam will actually make the ice off the back of the coil fall off, so you just keep applying towards the top. That's where the majority of the ice is until and i'm watching that drain pan as soon as the drain pan fills up because i'm putting more water, then the drain can drain out. You know faster um, then we stop okay, but i'm gon na show you guys, like i'm, not gon na get to the back of this coil with water, but i'll show you the back of it. You can see that it is frozen up.

Okay, so we're just gon na keep applying it and what, in a little while all of a sudden, a big chunk will fall off the back, and this is what i'm talking about. It'll just fall off as a chunk, then i'll. Take that ice, throw it in the drain pan and then just melt it and let it go down the drain. Sometimes you can grab a bucket or something you know.

It's usually not a big deal, but so this side is completely defrosted. Now we're going to start on this side all right. This one just fell off and i just started on this one and then literally everything fell off as one giant chunk because it was just sitting there thawing out. You know, as i was doing this so just you don't need to make a big mess in here.

I mean yes, there's a little bit of ice, you know here and there we're going to try to pick up most of it. Then you always have to get into the expansion valve section and the electrical section, and you need to make sure there's no ice buildup in there too. All the ice has to be gone or you're defeating the purpose of what you're doing and it'll be coming back. Tomorrow, understanding how your customers use the equipment is so important, so i'm standing in here and these guys just brought in piping hot food that just came out of the oven and they're using the box to cool it.

When i sized this equipment, i oversized it for that reason. Okay, now you can get super engineer, techie and figure out the exact amount, but we just basically oversized accordingly, you know uh. I think i don't remember what my number was. I think i went 10 over what the actual load was and it's to compensate for them bringing hot food into this box.

So we got the coil all completely done. The other side put together, i'm just finishing up the expansion valve section now. So that's very interesting. The problem is actually with the low speed on the motor and it's causing it not to work, there's something going on there, because i wired it up without hooking up the low speed and it's running at full blast, we'll let it run for a bit and see If it dies out, i may not have to change the motors temporarily, all right so um, that's my two speed relay right there, that black relay and the red wire is the low speed.

So the thermostat the way it's wired, the thermostat gives a call and energizes the relay. That's actually a normally closed relay, but when uh the thermostat calls it opens and then sends it to low speed, and you can actually see it right here. So there's your contacts and there's your relay and the relay is powered by the thermostat so when it gets a call for cool the relay energizes and it opens the contacts, it breaks the red wire. So if you want to disable two speed on these, all you have to do is remove the red wire and isolate it and or not hook up the red wire uh to the motor and you can temporarily bypass it.

So we're still going to order the oem motor, but for now we're going to leave it into full speed and just disconnect the red wire on both coils, because the other motor seems to be working for now. So the entire time i was defrosting, the other coil. I had this one running with no refrigeration, so it was partially defrosting it. Now this one was iced up the same way as the other one.

It had a big block. You know where it looked like it had been defrosting itself, so um we're going to go ahead and get this guy taken care of real, quick and uh also isolated, like i said earlier, the high speed for the fans right here so that way these will run On high speed too so all right and get this guy defrosted now this was all underneath here and remember. I said that when i defrosted the ice falls off, i don't want it to start knocking over wine bottles, so carefully moved all that stuff and then now we're going to finish defrosting this guy something else the customer informed me is that see originally when i called They said they just noticed the fan motor being bad well. On the other coil, i think it's been bad for a very long time.

Look at the thickness of this ice and you can tell that it had been thawing and then re-freezing and thawing and re-freezing, but it could be that other fan motor that was not working, that that was the problem i was assuming because it had just happened. I was like nah that you know i doubt that would cause it to ice up, but in further talking to them it's been like that for a while, so the fan motor could be the cause, but we're not just gon na stop there we're going to keep Going trying to figure out the root cause of this problem, i have a feeling it's going to be the the door too, but we'll see all right. We are all done, defrosting it. So what i'm going to do is i'm going to turn the condensing unit on.

I still got to clean up messes and everything, but i want the system coming down in temperature, while i'm doing things we're trying to multitask and trying to make the best of our time so back up and running and then i'll get downstairs clean up the hoses Clean up the box and then hopefully, it'll start dropping in temp and then we'll evaluate the system all right, so the system's been running for a little bit: 42 degrees, uh return, air temperature and the temperature controller says 42 degrees. Also, the next thing we want to do we're trying to wait for it to come down to temp to make sure that it satisfies and stuff. We may or may not see that, but we want to see we're going to hold down the enter button. We want to see what it's set at t5 is the set point 35 degrees in a perfect world.

You want to maintain 35 well. Let me explain this hold on so 35 degrees. We're actually going to change that. Okay, so we're going to change it to 37..

Hold down the enter and i'll explain everything right now. Differential is three so 35 degrees. It's going to come down to 35 and it's not going to turn on until 38, the end of 38. Then it's going to come down to 35 turn back on at 38..

All right so um, i adjusted the temperature from 35 up to 37. So now it's going to come up to 38, 39, 40 and then turn on now um. I don't like raising it that high, but with the customer that i feel is leaving the door open consistently. I feel like this is something we're gon na have to do.

Compressor starts per hour, none defrost per day, six we're gon na change that to eight, because i feel like they're, really being problematic with this and then defrost time 15 minutes we're actually going to change it to 20 minutes oops wrong button. Defrost time we're going to change it to 20 minutes hold that down. Everything else is alarmed, so we don't need to worry about that stuff. Okay, so we're gon na.

Let the box satisfy make sure it actually turns off where it's supposed to at least that's the plan. But the product in here is pretty warm, so it might take a while so we're gon na. Let it run for a little bit longer and see what happens. All right, we are running, i'm going to show you guys all the numbers here in a second we're running a clear sight: glass, which is an absolute must bottom line period, no ifs, ands or buts.

The system has a receiver and it has expansion valves that sight glass has to be clear period. I can't stress that enough. Okay, now, a really important thing to understand, though, is that sight glass is just a window into the system at the point that it's installed in a perfect world. You'll have a sight glass installed literally before the expansion valve okay on the liquid line, because that's going to tell you that you literally have a clear, solid column of liquid going to the expansion valve okay.

But for practicality. A lot of times sight glasses are installed on the roof. Okay, there's always potential that there could be a restriction. After that sight, glass, there could be a pinch in the liquid line.

There could be. Who knows? Okay, so just understand that sight. Glasses are extremely important in refrigeration and, if someone's telling you that you don't need a sight glass in refrigeration, when you have expansion, valves and receivers, you need to do some research, because you, you need to have a clear, solid column of liquid. You do not charge a refrigeration system with an expansion valve to super heat or sub cooling.

Okay, oftentimes on legacy systems, older systems, sub cooling was a good metric to tell you if you have a gross overcharge, but other than that with the receiver. It was complicated to use sub cooling now on newer systems like this is a new uh department of energy, awef compliant refrigeration unit. It has a sub cooler added to the system, so, as the refrigerant comes out of the condenser, it goes into. The receiver comes out of the receiver, goes back into the condenser.

Okay, then comes out of the condenser goes through the liquid line, filter drive than downstairs, and they do that to get extra sub cooling normally on a refrigeration system. You can't really measure sub cooling very well and i'll. Take you over here and show you guys, okay, that on these newer systems, you can measure sub cooling. Look at.

We have 11 degrees sub coin. That's that's crazy to see that on systems previous to these new doe compliant awef, condensing units all right - and i am checking on the inlet of the uh, the the liquid line, filter dryer. So it's the line going down okay before, if you just saw any sub coin or you saw an extremely high sub coin, that would mean something, but with that being said, still need to have a clear sight: glass, okay, so my box temperature. Let's get to that! Okay, this is 448a um.

I'm not really worried about targets right now: okay, uh! I guess i should get an outside air temperature, but we have a 20 degree evaporator td right now. My box temperature is 45 degrees. Now, a few minutes ago i was 42. So i bet you they got the door propped open right now.

Now we're going to go, do a test right now: okay and we're going to check the evaporator superheat, but we have multiple evaporators. So what i have lined up here, evaporator 1, has 11.6 degrees. Evaporator 2 has 11.6 and the compressor has 27 degrees super heat. Okay, sometimes you need to sacrifice evaporator superheat to satisfy compressor superheat, but i'm not too worried about this.

This looks pretty darn good to me, um with measure quick, you're able to do a multiple superheat test. So i have one uh suction pressure port downstairs and then i have three temperature clamps two downstairs one upstairs so we're able to get multi super heats on that. Okay, now, the other thing i do want to do is uh check my outdoor ambient temperature just to see um where we're at, but i'm happy with these numbers. This system is doing everything that i believe it can do.

Of course, you know we could always adjust the superheat a little bit lower, but i'm not too worried about it, as the valves are opening and closing it's kind of fluctuating and as it actually gets closer to set point we're going to be a little bit better. I've seen the superheat as low as 9.8 degrees, while i've been watching it today, so i'm not going to try adjusting it. If we had an electronic expansion valve, we could probably try to bring that superheat down a little bit more. But when you have thermostatic expansion valves you you try to go a little conservative, because uh thermostatic expansion valves can have high swings, open, closed open closed and you could flood out the compressor.

I mean again, that's that's it's not as critical but still okay. So we're going to leave it where it is for the evaporator superheat measurement and that should be - i might have even made some labels right here - uh! No, i didn't write it down, but that that sounds about what it was when i started this system up, because i remember starting this up so you can see. I started it up on 428 21, so we definitely are going to be getting a new evaporator fan motor and it should be under warranty through the oem manufacturer, but my labor is not because we passed our 90 days, labor warranty so uh yeah. So there we go we're hitting 10 degrees on the super heat, so we're going to let the system stabilize run a little bit longer.

You typically don't want to make superheat adjustments till you're really close to box temperature. It's marginal. I i honestly would like to see it at 40 degrees before you start adjusting the valve um, but i'm pretty confident we're looking pretty good. So far it's frustrating i went downstairs and they had the door propped open, like i thought so.

I just got on one of the cooks because they prop it open because oh i'm going in and out, i don't care, you shut the door every time you go in and out and you know that's an inconvenience to them like you know, to be fair they're. So short staffed right now, these guys are just stressed to the max, but it's still frustrating on my part, because it's saturday october 9th it's currently 203 pm in the afternoon. You know i'm i'm here on a saturday and again that's the life of a refrigeration guy, but i'd rather be home right now. Instead, i'm babysitting a walking cooler trying to figure out why i stop and at this point to be honest with you with the way they're leaving the door open, i'm about ready to just leave and tell them that i'll come back later, because i really want to Be done with this and i don't want to have to come back, but i guess i'm going to come back to change the fan motor anyways.

But it's just frustrating. You know when people leave a dang door open and they're, just so ignorant to the fact of what that can do to the system um. I did put my uh outdoor air probe on there. So what is it we're right about? At our target super i mean our target outdoor air temp road.

You know roughly uh, see our condenser tv is 24 degrees, where's that i must have passed the outdoor air temp. I wasn't paying attention on the next screen there. You go so it's 80 degrees outside right now, so just gon na let it run for a little bit longer, so the unit actually went into a defrost. So i think you can pop it out by holding down the two buttons i think yeah there we go.

So i popped it out of defrost. It's still! That's not 45 in here it's like 42, but it'll come down here in just a second but yeah i'm gon na get out of here because they just keep opening this door we'll come back and we'll follow up when we change this evaporator fan motor all right. I'm back today uh, it's just been a day. Luckily, my local supply house had the oem motor in stock, so we're gon na slap it in on this one right here and then we also got ta turn it back to uh the two speed function because remember i disconnected that so we're gon na do that Real quick shouldn't take long at all and uh good sign, nothing's iced up, so all right, so we're wired back in we run on low speed because the temperature controller's not calling yet i set them both back up to have the two speed fans and then, as Soon, as this temperature controller calls, we should ramp up to high speed, so it just uses that relay and whenever it gets a call for cooling.

It uh breaks the leg to that red wire breaks, the power to the red wire and it runs up to high speed. So, let's give it a sec while we're waiting, you can see all that hot food they just brought in here. That's something we have to be worried about when it comes to these walk-ins and you have to make sure stuff is sized accordingly, all right, high speed boom boom boom boom everything's on high speed now so everything's operating properly. They are running higher in temperature.

Now because i adjusted the temperature settings from 35 to 37, so it's going to maintain right around 40 degrees in the box now instead of 37, 36 degree or 30 well actually, 35 through 60.. So i was maintaining 38 before, but now we're gon na maintain 40. um, but we have to do that if they're constantly leaving the door open, uh, that's gon na, be it on this one we're gon na wrap it up. They should be good to go.

You know again it's okay to be frustrated right. I bring this up and i know i get pushback from it. People saying that i shouldn't be frustrated that i'm going out on an overtime service call i'm still frustrated. Okay, i'm human, i'm thankful right, but at the same time it's okay, i mean maybe it's just me, but i'm still i'm okay with this, like you know, i still get frustrated now.

I don't vent it to the customer, i'm polite to the customer and nice to the customer, but it's still frustrating i do let them know, though, like hey, like you know, immediately when i see walking doors left, open, walk in freezer doors and stuff, i go grab The management and grab cooks and whoever, like guys, you can't do this, you know, and then i expressed to them. This is my time. You know i'm here for emergencies, but when it can be things that that could have been prevented, it makes me frustrated. You know and - and i had a very long discussion with the general manager of this location because he wasn't there on the saturday, but he was there when i went back on monday or whatever, and i had a discussion with him like look, i get it.

I know things are crazy right now. These restaurants are just it's crazy, you know, and they have to pick their battles with the employees, because they they're just thankful that they have any because most of them don't - and if you guys don't already know this. This is how this is going right now, there's a lot of restaurants that don't get to open at all and they constantly have to stay, shut or shut down or only serve. You know, take out and things like that, because they just don't have staff.

So it's nuts right now so they're picking their battles when it comes to this stuff, okay, but um. I i went through everything that i could. I found the unit to be frozen up, but, as i was waiting for it to come down to temperature, i said in the video hey look, the temp went up like four degrees. I bet you, the door's open, i went downstairs and that door was wide open.

I had a conversation with the cook because he's like, oh i'm, going in and out with these trays, and i was like then shut the door every time you go in and out like stop it. You know it's annoying and - and this is what's causing these problems and the customer changing protocols right when they built this building, they were not bringing hot food into this box. This is something new okay. This is a new trend that they started to do now.

Luckily, from the beginning, this equipment was oversized, but still okay. You have to be careful because you don't want to oversize equipment too much, because that messes with the operation of the box, but at the same time, if you know they're, going to be doing things like having a lot of people in there. You know you have to account for that stuff and you can get nitty gritty with the engineering calculations. You know if you do a load calculation most of the advanced load calculation programs out there will ask you how many lights are in the box.

What's the infiltration rate, how many times is the door being open? How many people are in there on average? Do they drive forklifts in there? Do they drive cars in there i mean that stuff happens in the industrial side and you have to account for it. Okay, so um, but when i do size, what i typically will do is i'll take the load and then i'll, add 10 or i'll set it up for a heavy duty load calculation and just kind of i don't ever just throw 10 on it. I look at it and i see okay, how is this going to change? You know if i go up 10? Is that going to change a coil size? What's it you know, so i play with the numbers that way and just kind of, but you don't want to oversize equipment like dramatically, because then it's not going to get proper compressor cooling. If you have massively oversized equipment, then it's going to have short cycles.

It's not going to run very long. It you know, depending on what the product is in the box. It might you know not dehumidify. You know there could be all kinds of different problems that are associated with it.

Um. You know mismatched equipment. If you have a really big condensing unit and a really small evaporator, you might not get proper compressor cooling different things like that, so sizing your equipment is very, very important. Okay, i just recently discovered that uh heatcraft refrigeration actually has an app that has a load calculation software - i didn't know they had an app.

I knew you can go online and look it up, but it's called the hub. I think if you download the hub by heatcraft, you can actually, i think you have to sign in or something, but you can actually do a load calculation. So that's really cool. It makes it easier for us technicians, you know, because if we find a problematic box boom do a load calculation, real, quick, just solve the problem.

Is it? Is it oversized undersized? Oh wow, this is severely undersized, i'm not going to waste my time today. You know so that's really neat to have that stuff at our fingertips every day. There's something new coming out in our trade. That's making our jobs easier and easier.

Sometimes it's making it harder, but for the most part the new technologies that's coming out is making things easier. So that's really cool guys um, but it's important that you know we, even though i'm frustrated, even though we're going through this equipment on a saturday. I still take the time to not make a giant mess in the box. You know.

Sometimes it calls for a mess. Sometimes, if it's a ceiling mounted coil, you got to do what you got to do, but i still communicate with management. I don't just make it and leave i let them know hey. This is going to make a mess.

Do you want to cover anything up? Do you want me and i'll usually offer too? Do you want me to clean it up, i'm totally willing to clean up my messes most of the time i'll say hey. Would you like me to clean up this mess that i made, or do you want one of your cooks to do it? Most of the time they want the cooks to do it because they cost a lot less than me, but if they ever told me no, i want you to clean okay, no problem i'll squeegee that stuff up i'll get a mop out i'll dry i'll, do whatever They want i'm getting paid, you know, so i'm still courteous. I still am aware and observant of what's going on um, you know i'm paying attention to their habits as they're, going in and out of the box. All of that stuff makes you a better technician.

It makes you more aware of the situation and and gives you a better idea what might be going on okay, because every manager out there when you talk to them, i think they're leaving the door open. Oh, we don't leave the doors open. Oh you! Don't! Okay! Cool walk with me, real quick. Let me show you something: you know: walk of their boom doors wide open.

Oh, you know like sometimes they're oblivious to what's going on, because these managers again sometimes they're under staffed restaurants, and they don't even know what's going on in the back of the kitchen. You know and i'll bring this up to them. Oh yeah, you know they usually go quiet when they see the door wide open, and i always make a point too to grab my pocketknife cut off the bungee cords cut off whatever's tying the doors open, cut it off right in front of them and say these Are not allowed you make sure they don't do these. You know and they're, usually like okay, yeah, good idea all right, so we are as thorough as possible when we're going through this equipment.

Now i went back in put in the new evaporator fan motor set. It back up for the two speed option. Now i did make a comment that the two-speed option can somebody sometimes be problematic? Okay, because the way that these coils are set up is whenever the thermostat gives a call for cooling. It puts the unit into full speed right and whenever the thermostat satisfies it, takes the unit and slows down the evaporative fan motors.

Now this particular situation. The thermostat is the defrost clock. So, whenever it's in defrost it's on low speed, which doesn't really make sense, it should be on high speed. So i have run into some problems with this, but i don't like to jump to conclusions so i usually give it one to two shots.

So i had a freeze up situation. I went ahead and put the system back to oem specs, it's back to operation. I adjusted the temperature a little bit warmer. If i have consistent freezing up problems, then i'll probably explore the option of eliminating that two-speed evaporator fan motor.

They are going to lose a little bit of energy conservation efficiency, whatever you want to say when i do that, but that savings and energy is probably going to be outweighed by my repair costs of constantly having to come out on overtime and charge. The crap ton of money to defrost the coil. Now, if that's what caused it see, i don't think that's the cause of this situation. I think it was because they left the door open.

I think the fan wasn't helping, but i don't think the fan was the deliberate cause. I mean the the ultimate cause of it icing up. So try to do our best, that's the best. That's the best that i can do is just try to be as good as possible.

Try to be observant, try to pay attention to the equipment and get it back and operational okay. I really appreciate you making it to the end of the video. Thank you. So very much if you haven't already please consider subscribing to the channel leave me a comment down in the bottom.

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Okay.