This video is brought to you by spore'ln quality, integrity and tradition. We have a walk-in freezer, that's not working properly. The complaint is that the box temp is high. I walked into the evaporator section, the fans are not running, doesn't make any sound at all.

I come up onto the roof nothing's running no sound at all, so we're gon na open this unit up start checking, voltages and figure out. What's going on. Ok, I wanted to stop for a second here and just give a brief reek or rundown of how this walk-in freezer works. For those of you that don't understand okay, so this is a walk-in freezer and it's here to maintain their their product at below.

Freezing. Okay, typically on most walk-in freezers in restaurants, we want to maintain about negative 10 degrees Boxton, because negative 10 degrees is kind of the perfect temperature to store ice cream at so. The sequence of operation is the condensing unit on the roof. Has electrical control over the evaporator section downstairs? This is an electric defrost system, okay, so each each system can be different, but electric defrost, the defrost clock which happens to be located on the roof, is essentially the brain of the walk-in freezer.

Okay, the defrost clock sends power down via the number 4 terminal, to make the evaporator fan motors run, and then it also gives power to the thermostat, which decides whether it's warm enough in the box to send power to the liquid line. Solenoid valve, which opens and opens the flow of refrigerant back up to the condensing unit. The low pressure control senses that pressure that the liquid line solenoid valve is opened and it turns on the condensing unit. So the condensing unit can cycle via the temperature controller, but the defrost clock at any given point can turn everything off and turn the defrost heaters on to try to melt any frost that might build up it's very natural for frost to build up on a walk-in Freezer, okay, so now that you kind of have an understanding of how this walk-in freezer works.

When I mentioned in the in the very intro right there I said you know: I walked into the box. There was no fan motors running, there's nothing running on Rufe, that's peculiar and the the defrost clock did not have the heaters energized. So that's why I was saying something quite wasn't: right. Okay, so we'll get into the video now and then I'll explain some more so I've got the unit opened up.

Nothing super scary, jumping out at me, so the first thing I'm gon na do this thing. Has an auto reaiiy mean a manual reset pressure control right here. I want to push this okay pressure. Control was tripped, condenser fan motors came on, so that means that it went off on high pressure for some strange odd reason.

So I'm going to put some gauges on this unit and check it out, so my pressures already are pretty high, just standing pressures. It tripped the high pressure controlled again by the time I went downstairs. So this is my standing pressures. I'm gon na go and reset it again.

She didn't even reset because it has an dropped, love enough, just like a probably as I'm looking at this there's an oil leak somewhere right here too, because there's oil everywhere and I put some soap bubbles on the threads and I'm not seeing anything. Yet. I owe ya: there's bubbles coming out of this cap right here with their straighter zat there you go right, that's right here, tiny tiny bubbles, but enough to be a nuisance leak, so we'll make sure we fix that today interesting. So I got it to reset, but then it pumped down so now.

I need to go downstairs and find out why it's pumped down something that's going on here that caused this unit. To stop working so originally was tripped the high pressure. Once I reset that and went downstairs, it came back up. It was tripped again.

I reset it. It started up and then it pumped down and also the low pressure control is sticky. It wasn't a shutting off. I had to whack it with a wrench to get it to shut off it pulled into a vacuum, so we got to go downstairs and figure out.

Why we are pumping down come into the box and excellent switches off now that isn't? That was because they were trying to self diagnose it, but the high pressure control was the problem. My unit is running now now that I turned that switch on in mind. You, like, I said that switch was because they were in there flipping things trying to fix it this morning, but the high pressure control of the problem so we're running a clear sight. Glass.

It's gon na be hard to see with the camera. My pressures are about where they should be. It's about a hundred five hundred six degrees, 130 degrees, saturation, temp, I'd expect to see about a twenty, five or thirty degree rise over ambient on the condensing ten. These pressure controls are known to go bad.

This is the little encapsulated and they're. No, not the pressure cut out should before ten on that one, and I bet you anything that cuts out sooner. So what I'm gon na do is block off this condenser and simulate slowly and see if I can get this pressure controlled a trip just put a panel on it. We're gon na watch see what a trip sir.

So we cut out about 380 psi. It would be expected that we might hit 380 psi, because if we had about 110 115, which is possible because we're out in the high desert of Southern California, we would trip the pressure control early. So the solution here is we're gon na clean up that condenser and we're gon na change that pressure control to a different style, because those are just very, very unreliable. Now that you kind of understand a little bit, like I explained in the beginning on how the sequence of operation works down at the evaporator okay and how the defrost clock kind of has control over that.

Let's talk about on the roof. Okay, we have three-phase power on this unit coming in three-phase, power goes and sits at the top of the compressor contactor. Okay, there's also a control circuit that comes off of that three-phase power usually take two legs, so it's going to be a 208 single-phase control circuit and the power is going to one leg of the power is going to run through the pressure controls. It's going to go through the high pressure control and the low pressure control, and then it's going to go to the compressor contactor.

So when the liquid line solenoid valve downstairs opens up and sends power or Cyn's refrigerant up to the roof. Okay or let's the refrigerant flow back up to the compressor, the pressure controls are what interprets that pressure signal. Okay, let's call it a signal or a pressure reading and says: hey, there's pressure here, it's time to turn the compressor on. That's what the low pressure control sees? Okay, but the high pressure control is also they're, usually wired in series, but not always, but in this case it is it's wired in series with the low pressure control and it says: hey: hey, wait a minute something's wrong.

It's time to shut off okay in our situation, what we found was that the high pressure control was not working correctly. The proper cutout pressure on that particular p-nut style, high pressure control was 410 psi and we were in, like the 380 range and kind of like. I mentioned in the video with the high ambient temperatures that we're having, on average, the condensing temperature. Okay, if we have a hundred and twenty degree day, which is you know, it's rare, but it does happen.

Okay, we hit 115 117 120, then you're, condensing temperatures, and you know that pressure control not cutting out at the right pressure causes an issue it caused it to prematurely trip. Essentially, okay back to the video now okay to get started. What we're gon na do. I've got the new pressure control, we're gon na pump the system down to a very low pressure, because we're going to change the low pressure control to we're going to put in a dual pressure control.

So we're going to front-seat the receiver valve yeah and then we're gon na watch the unit pump down once it gets low enough, I'm going to shut the system off because I don't want it to go into a vacuum. I just wanted to be about 10 psi. 5 to 10, because we're going to have to disconnect this under pressure, this low side port so showing off bout right there and let it sit if it rises too much I'll turn it back on, but 7 psi is pretty good when it gets this hot outside Kind of like throw a towel or something over your gauges or you'll ruin the screen on them. So all right next thing we're going to put in a dual pressure: control I'll show you guys how I'm going to do that, and because we we're going to stall high pressure in here.

So we're going to utilize this port right here. That's actually leaking and put a permanent cap on it and we'll put an access T on it. Actually leakin anyways, so we needed to do something with it. So I'll put the access key on it and then we'll be able to put the high pressure control on that.

I'm gon na go something like that perfect, so hot out here my phone's overheating. It doesn't even seem that hot, it's only a hundred and twelve, but whatever seems like it's been a lot hotter than that before, but okay. So because my phone was overheating, I wasn't able to get the whole process here, because I tried to film some of it. Put a new dual pressure: control routed, the capillary tubes.

I did it while it was under pressure notice. We still have six pounds of pressure on the low side and that's because I just pulled that off and pop that on real quick under pressure, I used an existing Schrader port on the high side and this has a Schrader depressor in there. So I screwed this on put the Schrader in here then screw that on hot, while it had pressure under it to put and tighten it up that way, I could do a live. I tried to route the capillary tube, so they wouldn't rub out on anything.

I have no choice. I tried unscrewing this and it seems like the Schrader's, not there or the Schrader's busted on the other side of it, because these normally come with a Schrader under it, but I keep unscrewing it. I got it to just about the last thread and the Schrader never closed, so it's just spray and refrigerant, so I'm just gon na leave that on for now, hopefully it doesn't leak. Our leak that I had found earlier was on that tap right here.

Remember so so that's it we're ready to turn this guy on and hope that I wired it right pressures kickin in let's see where we cut in at we're kind of holding out, Oh duh, silly still pumped down hot I'm a all right. This is good, though, because I can actually crack it and see where it actually turns on it. So I'm gon na give you guys that view you can see what it actually turns on that on at 26 psi, let's see where it turns off at so that's good, and then this is an auto reset. I know I'm gon na get all the people saying you should always have a manual reset.

Well, it gets so damn hot here. If we have a manual reset I'll be out here every day, so we set it for Auto reset about 450 psi and yeah we're going to get this guy going. Alright, we are pretty much going to wrap it up. I'm going to go downstairs, make sure we've got some noticeable drop in temperature, I'm not going to watch this thing come down to temp, I'm confident that we fixed the problem.

So I clean the condenser, so I still have a wet coil right now so, but head pressure dropped significantly. Psych loss is still clear. So that means the charge is good, because if we've got a wet coil and a clear sight, glass and this unit has a head master, that means that the winter charges is good. So we know we're good on charge.

So I'm going to button it up. Watch you come down a little bit more, get my tools off the roof and then go check on the box. Ten, all right, we are running it's gon na be a long time. It's currently about 20 degrees in the box there ice cream is all hammered liquid ice cream, but everything else is still somewhat frozen.

So it'll take some time. Okay, hopefully you guys got that and I didn't confuse the heck out of you. Okay, I tried to throw in some some audio. You know where I thought.

Maybe I should have explained things a little bit better, but overall we had a walk-in freezer service. Call when I arrived, I kind of jumped ahead of you know the the normal troubleshooting steps, because I knew some things you know, and I went right to that pressure control. Okay, so you didn't seem to get my meter out and start troubleshooting just because I was so familiar with the sequence of operation. The first thing I did was pushed on the pressure control.

When the system came on, I knew something was funky there. Okay and that's when I found that the pressure control wasn't cutting out at the correct pressure, okay and with our ambient temperatures, it would be expected that we would exceed that 380 PSI. Potentially, okay. So that's why I went ahead and changed that pressure control now very controversial.

You know I some people won't agree with it, but I put in Auto reset pressure controls, okay, because I really don't have time to go back. I just make sure I don't set them about 450 psi, but I will say you need to be careful because, especially when you get into the scroll compressors, they don't like those high pressures and they tend to have issues so. But I still even on the scroll compressors install auto reset pressure controls. I just make sure that I have them set correctly.

The peanut style control that I pulled off of this system. They're junk. Okay. I don't like to talk crap about people's products, but they do not last in the very beginning, they'll work and they'll function correctly, but after a few years, they're not accurate and they're not adjustable.

That's the problem, they're convenient and the fact that they fit into tight places, and I understand why the manufacturer used them, because it's easier, it's cheaper. They can throw one of those on and call it a day. I've used them before. I still install like air conditioners and stuff where I don't want to install a pressure control, so I mean they're unnecessary evil.

You know. Sometimes you just got to use them, but you know, if at all possible, I try not to use those style pressure, controls, okay, but went ahead and reset that replace the pressure control put in a dual pressure control system. Okay, I did have to rewire some stuff, because this particular condensing unit did have a low ambient control circuit. Basically, that would ignore the pressure control and let the system run in case the system was bypassing or the headmaster was starting to bypass when it had a really low ambient temperature.

That's a whole nother subject. Maybe I can go through that that one's kind of confusing and how that works. But I don't need that low ambient system here and I went ahead and pulled that out of the picture and just made it a basic system where the pressure controls control the compressor. Contactor and that's it other than that, guys that really wasn't much more going on with it.

I did not watch the Box come down fully in temperature, most of the time on walk-in freezers. I don't as long as I see a significant temperature drop and I don't find any other issues with it. You know in my head, I kind of have an idea what the pressure should be. It's very important that when you're working on this kind of equipment, you know you really shouldn't be putting your service gauges on there.

Unless you understand what the pressure should be on a typical walk-in freezer, I know, especially if it doesn't have a microchannel condenser, you're, typically going to be 25 to 30 degrees over ambient on your condensing temp and down at the evaporator. We're typically going to have a 10 degree, evaporator TD, so that means whatever the box temp is my such or my lick. My vapor saturation temperature or my evaporator temperature will typically be 10 degrees below the box temp for the most part, now evaporator, the TD. You know that's mainly when it's closer to being down to temp, okay and your expansion valve will change that.

So when your expansion valve opens and closes that evaporator temperature will fluctuate okay, so it's very important that you don't assume that your pressure should be this right on startup you've got to let it stabilize out it's important to make sure you have a clear sight glass On any refrigeration system that has an expansion valve, it's requiring a full column of liquid going to that expansion valve okay. So it's very important that we have a full call it a column of liquid going to the expansion valve. That's one of the first things I check, then I look for that condensing tempo ver ambient approximately 25 to 30 degrees. Above that look at my evaporator box temp, I shouldn't say: look at my box temp and then once I get close to being down to temp.

Look at my evaporator TD, which should be about 10 degrees below box, temp that that's the liquid or the vapor saturation temperature of the evaporator tempo K. So that kind of gives you an idea where your pressure should be. I don't really pay so much attention to pressures per se as much as I do, the the saturation temperatures - that's the really important thing to understand, if any of you guys are making the switch from air conditioning to refrigeration. If you can understand that that will get you a long way, you really should understand that in air conditioning too, because it really simplifies a lot of things.

You know, if someone says hey, what should your pressures be? On 410 - a I don't know, but I know that my evaporator temperature is supposed to be. You know whatever. I know you know. On 404, a I know my evaporator temperature should be, but do I know what the pressure should be and not so much, but I can remember the evaporator temperature.

So if you can look at temperatures, it'll actually make your job easier and you can get used to it and start understanding. You know on most air conditioners: you're gon na have a 35 degree TD on the evaporator, so that means whatever the space temp is your suction saturation temperature or your evaporator temperature will approximately be 35 degrees below that you know what it could change a little bit With every manufacturer, but as long as you kind of have a general idea, what your pressure should be, whether you're working on air conditioning or refrigeration, it's really gon na help, you okay or what your saturation temperature should be. I should say I'm rambling at this point, so I'm gon na go ahead and close this up. I really appreciate you guys watching these videos.

Any questions you guys have. Please please send them to me. Hvac. Our videos at gmail.com is my email address.

I go live Monday night's work permitting at 5:00 p.m. Pacific time on YouTube, and I usually answer as many questions as I can I'm on there for about an hour and a half. So I try to get to everybody's questions. Send me comments on Facebook on Instagram.

On the YouTube stuff, I try to get to it all as much as possible. Okay and then I'll usually address it. If I get repeat repetitive, questions like over and over from different people I'll definitely address those on the live stream. When I go live okay other than that guys, we will catch you on the next one.

Okay.