This video is brought to you by Heatcraft Worldwide. Refrigeration Morning I Got an emergency walk-in freezer service call. They said it's not cold enough here. it's like 10 and we've got an iced up coil so iced up top to bottom, front to back all the way through.

I Can see it in there. So our first step is to jump onto the roof because that is where the Defrost clock is at and all the controls. We're going to throw the unit into a defrost, test the heaters, test the limit switches, and then we'll uh, we'll get it all defrosted and see if that fix. So this is our running system.

now. remember, we have a completely iced up coil. If you look down here, the sight glass is flashing, but that is irrelevant when the coil's iced up. Okay, we cannot judge A System's charge when it is frozen up.

sight glass can be flashing can be whatever. But once we get a defrosted, that's when we really got to take into account everything that's going on. Um, this, this is our Defrost clock. Let's see, it is 10:43 It has the right time on it.

Okay, so let's go ahead and test it to see and it looks like I just changed this back in August So shouldn't be anything wrong with the clock, but let's see if it's defrosting. So we'll go ahead and click it into Defrost. It should pump down and it's not all right. It's not turning off, it should be going into a Defrost right now.

We'll get the meter out and check it all right? So I'm testing from 1 to N and we get 210 volts. Okay, that's one right here and that's powering the clock in in. Okay, so that means that the the clock itself has the right power. 1 to N 208 volts.

That's good. Okay, next thing we want to check is our Refrigeration circuit. Refrigeration circuit is the number four wire. So if we go from four to N right now with the green light on, we should have 28 volts.

Okay, there we go. 209 volts. That's fine. Um, so that means that we're in refrigeration mode now.

I Clicked it into Defrost. Okay, it should be going into Defrost mode, of which three to N three would be the heater circuit and in would be our neutral. I mean our common. Okay, so here you go and here you go.

We have no voltage from 3 to N. Which makes sense because we do not have a red light on. All right. So why is this clock not going into Defrost? Okay, I Have a feeling this Defrost termination switch is going to be the reason why.

So I'm going to turn off the power, we're going to disconnect the X terminal and we're going to test something before I turn it off. What I did was I went from four to X and we get 208 volts. Okay, so that actually proves my theory. What's happening here is the Defrost termination switch is either too warm and or is bad and it's sending power, not allowing the unit to go into Defrost at all.

Okay, now I have seen situations where there's so much ice around it. It causes problems too. But we do need to get this defrosting. So like I said.

I'm going to turn off the power real quick and then we'll disconnect it and test to see if it goes into Defrost. In all right now, I disconnect Ed the X wire going to the X terminal. Okay, and if we throw it into Defrost all of a sudden the red light came on and what's happening now? I Don't have gauges on it, but the unit's going to be pumping down. So if now we go and test between N and three, we should have power.

We have 208 volts. That is the heater circuit. So now the uh, the the electric strip heaters in the coil are energized, The fan should be turned off, which we can test by going between N and four, and we have zero or 3 volts. Nothing okay between N and four.

So the refrigeration circuit is no longer being powered. My unit just pumped down and shut off. Okay, so we proved our theory that the Defrost termination switch was terminating Defrost and not allowing it to go in. Now the question is why? Okay, so we're going to let it run in a Defrost right now.

we're going to leave it energized while I Go downstairs, get all my hoses and all my stuff. I Will also check all the Defrost strip heaters to make sure they're working and they have uh, current across them. We'll check that and then once we get everything set up, we'll keep letting the defrost heaters run to try to melt some of the ice. while we're getting everything ready, we'll turn it off and defrost it properly.

All right. I Got the covers taken off? Um I Can't get the motors out yet because they're frozen in so we're going to have to melt around them first, but we are going to pull them out. Um, we opened up our electrical section over here. my uh, defrost termination switch is back there I Don't see anything wrong with it, but we'll have to test it.

Um, we're testing the drain pan heater right now and we've got an amp of current and then we just need to go grab every heater that's the upper coil heater. two 2 amps and then I'll have to get onto the middle heater. There's three total and there's the middle heater. So we have current on all the heaters.

It's about accurate. Usually run about an amp on the bottom and about two amps on the top two. Um, so heaters are working. We're going to let it keep running for a minute.

I Still got a few more things to get ready to defrost this, but then we'll run up and turn off the power and do it in order to get the motors out. I'm going to use hot water. I Don't ever use a torch or anything like that. The reason why I Don't use a torch Number one: I Find it takes a lot of time.

you can damage the coil, but also you have all your byproducts of combustion filling up the small space that you're working in. You have the potential to breathe in those byproducts and potential for carbon monoxide poisoning. So so your best bet, in my opinion, is hot water. It's the fastest, most efficient.

even cold water is better than a map, gas torch or something like that. Um, I'm just melting with the Mist setting on my wand around the motors once I Get that off, then I'll go to the high power shower setting and melt everything else and then I also put a pan down here just to catch some of the stuff. potentially cuz we don't want to get any water on the floor now that I've got the motors out. I Just go to town, but we're watching the water making sure we're not dripping off the coil too.

Um, cuz we don't want to get the water on the floor. Like I said, the problem with getting water on the floor in a walk-in freezer is that it will immediately freeze and then uh, or potentially get under the floor and freeze and lift up the floor and it's just a disaster. so you want to be very careful. So this is a Heatcraft coil and I really dig these.

The quality is just there. um I Like the fact that on the plugs down here they have little ears to keep this guy from pulling out. The only thing that I would change and I change myself is I put a double zip tie right here now. I've said before that I don't like Zip tiing the wires but in this situation I zip tied one wire to the fan bracket and then another zip tie to that so that way the cord is never touching the metal bracket because they will rub out.

um and in this situation I'm still able to unplug the wire and pull the whole assembly out so it's not impeding me. What I really get frustrated at is when people zip tie to other wires that I have to get in there and cut because we're defrosting coils pretty often so you can see this one right here had been rubbing and I'm eliminating that problem and we'll tape it up because it didn't break the jacket or anything. but I just dig how they have those ears to protect them. uh, unless people break them off cuz I've seen people break these things off or stick the wrong Motors in there and stuff.

so we'll tape that guy up and then I happen to have a defrost termination switch an Oem Bone 579 which is the correct one for this. um and it tells you too the the the settings and the cut cins and cutouts. Um, so basically it's going to uh, turn the fan on at 35, the evaporator fan motors and then turn the the defrost termination at 55. So um, all right, we're putting this back together.

Um, yeah. I just need to swap that. uh, Defrost termination switch. All right.

We got everything assembled. Uh, Defrost termination switch is installed. Um, everything's backed together. secured the wires taped up this wire in here.

At this point. I'm just going to clean up my messes. We're going to probe up on the system and uh, start it up and then check the system operation. make sure there's no other funky stuff going on.

More than likely this is customer. I've shown videos on this one before where I had an iced up coil actually back in August and I came back the next day and the door was bungeed open all night like they constantly bungee this dang door open right here. So that's a whole thing. And and I know everybody's going to ask me why not door switches and stuff I I Try man, but these customers.

they won't approve that stuff. but yet they'll approve for me to come out and defrost it all the time. It's just a pain in the butt. but anyways, we're going to.

but we're not going to. assume it's just the door. We're going to go through everything all right. We got this guy all back together.

Now the biggest issue is that's why we always test Defrost. When it's iced up. it wouldn't defrost. it would skip the defrost.

Cycles because the coil the defrost termination switch thought the coil was hot hotter than it was. Okay. so we need to, um, turn the system back on though. Got it all put back together, taped up the wires.

We're still going to test the system operation. We're going to gauge up on it, make sure the expansion valve is throttling correctly, make sure everything else is good. We're not just gonna stop at the Defrost termination switch. We're going to keep going to make sure everything else is good.

all right. Now the box is too warm for defrost and you can tell because I just turned it back on. the green light is on. but we're in Defrost so the Defrost termination switch is now working properly.

but that's because I have the box at like 50 right now, right? So um, we're going to uh, it's out of Defrost now. We're going to let the system stabilize I'm going to probe up and we'll check everything. So far, so good. everything's running.

Uh, it's going to be a little while so uh I'm probed up I Have to step over here because uh, the uh, we're having a hard time with communication cuz we're a ways away. So what I ended up doing was just walking over to the area above the walk-in freezer. The walk-in freezer is actually about 12 ft that way. but we're close enough here that we can actually see our system vitals.

Okay, so evaporator superheats high right now? Okay, that's pretty normal, especially as it's coming down now. Um, another reason why we're going to have high evaporator superheat. Let's go over here. Um, let's look at our evaporator.

TD Okay, the box is coming down in temperature, but notice we have a 27 evaporator. TD Here's what's happening. This unit is massively oversized right now because it's cooler outside. Okay, um, right now now.

Uh, let me go right here. We can see I think the temperature inside the space in there is about 82, but this equipment is sized for 120 because they get that here. It gets insane. That's why it's in that rack with the swamp cooler blowing on it because it it needs that.

So right now when it's cooler outside, we are running a higher evaporator. TD because our compressor is oversized at the moment. see how we have a 30 TD now. Also, that could be because the equipment could not be matched properly too and that can affect things.

Our condenser TD is is on the lower end. Uh, we do have sub cooling and we do have a sight glass that is clear. Um, let's go right here. subcooling about 1 so we know that we anything over zero right? We have 1 of sub coin.

So um, and we do have a clear sight glass. Uh, let's see again. Super Heat's High We're going to give it some time. Um, we're going to let it run for a little bit longer.

All right. I've watched it for a little bit. This is about all that I'm going to give them today. the Box temperature is down to about 6.

It's still got to come down to -10 Um, super heat is coming down. it's still a little bit on the hair side. Discharge line temperature is not too bad. 207 um.

superheats about 16. I'd like to see it get a little bit colder, but we still got a ways to come down. Um plus like I said, we have a high evaporator TD right now which is going to affect our superheat evap TD is about 22. So um, but everything's looking okay.

you know I mean not really much more we can do so we'll just tell them to keep an eye on it. but uh yeah, that's it for this one. I Very much appreciate on these heatcraft evaporator coils. Now this is climate control, but it's still heatcraft and I appreciate how the it disassembles and how everything just kind of goes together for the longest time.

I Used to struggle changing the limit switches cuz they were back behind the electrical panel until my brain started using my eyes and actually realized there's two screws and that whole electrical terminal board literally just pulls to the side and you have super easy access behind it. So I don't know what I was thinking for the longest time struggling with those because it's really not that bad once you kind of figure out how easy it is, right? Um, the other thing too is. uh, the the part numbers I appreciate that on the limit switches. Um, you know you have the part numbers and the tags are on there.

they're really easy to identify now. I Happen to stock those limit switches in my truck because we do go through them every once in a while. So it's just a good truck stock item that I keep in my truck. Now you know it may seem repetitive defrosting a walk-in freezer, you know? I I defrost a lot of them.

It happens a lot of times. it's my customers leaving doors open. Sometimes it's failed limit switches, sometimes it's failed. Defrost heaters, time clocks.

I Mean it can be all kinds of things. So even though it seems repetitive, you still got to take your time and do your due diligence. Make sure that you're following up. Don't just stop at the first problem.

Don't just stop there, right? Cuz we're here to solve the problem and not the symptom, right? Because the symptom is just that. it's iced up Okay, but we need to find out why it was iced up. What's the root cause? Dig into it. Look at the big picture, right? That's the biggest thing with this stuff.

I Analyzed the system pressures, looked at everything you know, and just went through and watched the box come down a temp. now. I didn't watch it fully come down because I was out there on overtime. Um I didn't want to be there all day long.

so once I was comfortable. Um I went ahead and told the customer to keep an eye on it. Followed up on it later and everything was good. So I really appreciate you making it to the end of the video.

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