This video is brought to you by sportlin quality integrity and tradition. Well, we got a walk-in cooler today, it's kind of a breath of fresh air to walk into new equipment. I forgot that i replaced this equipment recently, so uh 57 degrees. That's not good.

Come back here, there's no ice buildup! That's a good sign. Temperature controller says high alarm and it should be calling. So we know that our problems are going to be onto the roof. So we're going to go.

Get my sun hat and we'll jump up there and see if we can figure out what's going on with this guy all right, i come up onto the roof, my condensate, i took the cover off, but my condensing units here, it's not running so what i'm going To do is, go ahead and apply service gauges to this guy, and then we can diagnose what is going on. Does it have refrigerant? Is it a power related problem, we'll find out here in a minute all right? We are probed up the unit's still not running, and we have pressures so we're good on that aspect. Um. But i got ta say that that head pressure being that high, when it's not running kind of, indicates to me that we might be off on a high head pressure lockout.

Maybe let's see this is my low pressure control. One of these is a fan cycle. One of them is a head pressure control and looks like we got a lockout relay or it's a time delay, so it reduces the time at which it restarts. So if i turn that and maybe turn the power off and turn it back on, let's see if it tries to restart, i should be trying.

I'm just gon na do like a three minute time delay or something we're gon na give it a minute to see. If it restarts oh there, we go all right. So oh yeah, look at the head: pressure's, climbing 381 yeah! That's not good and uh! Let's go over here and see if we can figure out why this guy has high head pressure. Oh okay! That makes sense right.

Yeah all right turned it off um, so we got to clean these condensers. Look at this guy, that's horrible! All their condensers are like that that one's bad, that one's bad ac is bad. It's a mess. I gave it a quick brush, but it's really dirty inside too, but let's see what happens when i turn it on.

Look at that there's my tool: bag right! Oh yeah! It's just tripping high head pressure instantly. Now i had turned that relay. We need to have it on there for a couple minutes that way. It's an anti-short cycle really, basically so yeah we got ta clean these guys, not even brush and i'm just gon na.

Do it all right. Why is it that we would go off on high head pressure? Okay, a couple factors here: number one: your box temperature, the temperature inside the walk-in is 50-something degrees. Okay. That means that the evaporator the fan coil unit inside is going to move air across it's going to take the heat from in the space and it's going to absorb the heat and bring it back up to the compressor on the suction line.

So you've got a warm box. The suction line is bringing the gas back up because it's absorbing the heat into the refrigerant. It's coming back up on the suction line. It's going into the compressor, so you have a higher than normal temperature refrigerant.

Okay, then, on top of that, you have the heat of compression okay. This compressor uh is going to compress the refrigerant okay, so you're going to have a low temperature vapor refrigerant. Coming back all right and it's going to take that refrigerant and it's going to build up the pressure uh. It's going to uh, come out as a high temperature, high pressure, superheated vapor, coming out of the compressor okay and with the space temperature being high.

And then this guy creating heat by compressing the refrigerant. Then it's going to run through the condenser and it tries to reject the heat because you bring the outside air across the condenser and it should absorb the heat from the refrigerant just like it does, but the opposite on the evaporator downstairs, and it should blow that Heat out here, okay, so my condenser td is directly related to how clean this condenser is. Okay, the condenser td is the uh uh, the the saturation temperature of the refrigerant right compared to the outside air. Okay.

So my condenser td, on a system like this will probably be about 20 to 25 degrees on a normal day. Okay, but when the condenser is dirty, it can't reject that heat and we can have a catastrophic failure in the compressor, because that thing is just going to keep pumping and pumping until it destroys itself on the inside. So we have safety devices. We have a high temperature safety device right here and we have a high pressure safety device which again, i don't remember which one's the high pressure.

One of these is a fan cycle, one of them's high pressure, but you have a high pressure safety. That's protecting the compressor from basically imploding on itself; okay, so that is saving this system from ruining that compressor, because if we didn't - and now, though, those are auto reset pressure controls, if we didn't have that time, delay relay right there yeah, i guarantee we'd, have a Bad compressor, if the customer waited too long to call me, you know on off on off on off on up now. What's interesting, is these ones haven't tripped yet or maybe they have auto reset controls? I don't know, but we're going to clean all of these and get them up into tip top shape. Give this guy a rinse.

I don't think it's going to need cleaner. I just think it needs a good rinse as well. It doesn't look too too bad yeah. It's not bad, just a real big surface one and we'll we'll put a little more pressure, make sure we get it from the other side too.

There we go that one's going all the way through yeah it's coming through nice and clean. You guys went for a ride yeah. I can see right through the condenser now, so that's good. Putting these other ones off real, quick.

These condensers are hammered man really bad. This is also hot water, so i got to be careful. Hot water does a good job of cleaning, but we're gon na want it to make it trip the head pressure, control uh, all right. We got these guys rinsed we're going to do a quick rinse on the acs, but we're not going to spend hours doing it and i'm going to turn this guy on.

So all right now this guy's still pretty darn close it's at 353 for the head pressure. That's just the static pressure, so we're going to have to push this contactor in and because the refrigerant is going to have to do its work to cool this off. You know it's going to take a long time now. It also didn't help that we used hot water, but give it a minute of me just pushing in the contactor and it'll cool it down just going to take a minute.

Oh, it looks like we're not calling what the heck. Oh, i think it locked itself out. Yeah, we don't have suction pressure, interesting. Okay, i need to go, maybe reset the thermostat.

It actually went into a defrost. That's why it's not running! That makes sense, because i was tripping out thinking. Thermostat doesn't lock itself out, but, okay, that's why we're going to terminate defrost real, quick, all right, i'm holding in the contactor, because it's still not off on time delay but yeah. Now we're looking good so we're going to let the system run until the time delay opens or closes yeah close this and then uh we're gon na.

Let it come down and temp and monitor the operation, but i think we're gon na be okay. Sight. Glass is already clear, so we are running um pressure's, where i'd expect it to be see what our ambient temperature is right. Now it's about 100 degrees outside, so we got about a 30 degree, condensing temperature, something like that.

Um i mean it's doing everything it can box temperature is going to take a long time. We've got 21 degrees, compressor superheat. So that's good! That's cooling, the compressor off yeah, it's nice and cold. So that's going to help, there's not really much more.

We can do except for just wait for it to come down to temp all right. I am not going to wait for this to come down to temperature. We have some really good vitals. The box is dropping in temp.

We've got a cold suction line coming back, but it's not flooding. We've got a clear sight, glass pressures. Look good td looks good, i'm comfortable, walking away from this and telling the customer it's going to be about three four hours before it comes down to temp, because if you think about it honestly that food is probably all at 55 degrees, 56 degrees whatever it is. So it's gon na take some time, so i'm gon na put all the covers back on we're just uh doing a quick rinse on all the condensers real, quick, nothing crazy and we're gon na wrap it up.

This call was, i don't know about two months ago, a month and a half ago, something like that right at the end of the summer and uh. You know they sometimes can be easy, but you have to remember to not get in over your head and start getting lost in things right, because it's really easy for someone to jump in there and be like oh yeah, uh voltage and you know and get lost In in it's something as simple as a dirty condenser, okay, so it's so important! You know, i know a lot of people they like to think these calls out before they go. Okay. What could it be? You know getting a list of things, but sometimes you can overthink things and you can get in way over your head and it's something as simple as a dirty condenser going off on head pressure, for instance.

But you can't always just look at it right because you saw that after i brushed that condenser. It still was going off on high head pressure, so the customer could have gone up there and said: oh, it's dirty and brushed it off, and then you know if a tech wasn't really paying attention to what's going on, they might be thinking. Oh my gosh. It's overcharged all this stuff and it's like no stop and think about it.

You know: can you see through the condenser right, especially on something like this? This is a small little unit. You should be able to see through that condenser no problem right, so you just want to remember to slow down and take a step back at the you know, look at the big picture, kind of a thing right. You know it it's it's really easy. Sometimes, to get lost in your own mind and like psych yourself out and just you know, go in and go crazy, stop with or start with the basics.

Look at everything. So in that situation it wasn't running, i knew it was calling downstairs more than likely. I put my service gauges on it and right away. When i put my service gauges on it, the head pressure was higher than i thought it should be when it was off.

Okay, all right. This is a dead giveaway something's going on. You know, and i kind of already had a hunch - it was going to be a dirty condenser and that's what it ended up being. Okay, now it's always possible that someone could have overcharged it and it was off on high head pressure because of that.

But this is my store. Nobody else is really working here. You know, i have another tech, another couple texts that work, but you know i kind of have an idea that it's not going to be overcharged. It's probably just going to be a dirty condenser.

You know and uh i'm there i'm going to go ahead and hose everything else off too. Even if i'm busy you know, i'm slammed, i got a million things going on. The last thing i need is for another emergency service call later that night for another. One of those walk-in units - i got the hose up there, you might as well just rinse everything off now.

I didn't necessarily go through and do a full acid cleaning on every single condenser. No, no, and actually none of them even required condenser coil cleaner. It was just water that i needed now. Luckily, we had hot water.

Hot water can be very beneficial, but you also want to be careful because you blast that condenser down with really really hot water, then you turn it on and it might go off on high head pressure again because it's extremely hot you know you got to give It a few minutes to kind of cool off, so nothing too crazy. Here, just uh, you know throwback to the basics ones you know, but still we have to remember to not get in you know and let our mind make us think it's something bigger than it is right, we're just moving heat. That's all we're doing, and if we can't reject heat, we can't properly move heat right because the heat of the compression, the compressor needs to have cool suction gas. Coming back, you know the higher uh, i'm sorry the dirtier the condenser, the less heat it can reject and therefore the system's not going to operate properly.

It's it's really, not that difficult. When you break our job down we're moving heat from one place to another. Okay, we got a walk-in box, we're just dropping the temperature of the air inside the walk-in box and adversely dropping the temperature of the product. Okay, so we have to be able to absorb the heat in the evaporator.

Therefore, the evaporator has to be clean ice free. The airflow has to be proper right, then we absorb the heat through there. If our lines are sized right, that heat is moved back up to the compressor and then the compressor rejects the heat once it pumps it out into the condenser, rejects the heat, and then the cycle just keeps repeating so breaking it down to the basics. We're just absorbing heat down in the evaporator and we're rejecting heat at the condenser and if either of those are dirty, then those processes or sees or, however you want to say that is not going to happen and it's not going to work right.

So it's not rocket science all right. It's just physics, right physics, it's just science, man, science, all right! I really appreciate you guys making it to the end of this video. As usual, you guys are amazing. If you haven't already, please consider checking out my website.

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