Damn Brian, with the HVDC our school podcast and HCC our school comm today we're going to be replacing a piston with a t, -- xv on an r410a system that currently has a piston in place. We're going to demonstrate what's good about it, t XD, why it works well, and we're also going to show you the danfoss kit that you can get for replacing th CS and a lot of different applications. So here we go so one nice thing about the TR. 6 kit is that it fits really nicely in a van.

I think it's really easy. It's a store and you've got three different sizes of expansion valve inside this kit. It's got a really nice description selection table here. It's got a surge.

You had to do super heat adjustments correctly and another nice thing is: it actually shows you the amount of change that you get with every turn of the adjustment, which is really nice. They make our 22 and r410a kits. This is an r410a kit because we're working on an R for ten a system describes everything really well. So it's a nice, it's a nice kit to put on a truck, and then you've got three different kits for different tonnage is so, if you look here like this, this one here is the four and a half to five ton and they've got the three and A half to four tons, then you've got these smaller one one and a half to three tons and that's the one we're gon na be using today you open this up.

You've got the valve. Obviously the sensing bulb external equalizer and then you've got an assortment of different fittings here for connecting in different applications, as well as a nice little instructions to show you not only how to install it, but also Edison. The super neat and some other nice things which will will show as we kind of go through the process. So you can see this has a piston installed 70 piston, but the condenser shows that this should t -- xv.

If you look at the data tag, and so we are replacing this piston assembly with the Danfoss tr6 kit, we're gon na use the three ton expansion valve, because this unit is a three ton unit. You read that zero three six unit we are using this Universal tr6 kit, so currently refrigerant comes down liquid line into the piston assembly. This is where it's restricted and then it boils in the evaporator coil. We don't have currently any port for the external equalizer.

So we're gon na have to make that we're gon na have to mount the bulb here. You know obviously there's a lot of instructions about ideal locations for mounting bulbs and ports and all that kind of stuff, but you know in the field in reality, in a lot of cases, you're pretty limited, we can't go into the aluminum here. We have our tubes coming out of our vaporators section header right here, so that's going to be limited, so we really only have this point right here other than if we wanted to run it outside the cabinet, but as soon as you run it outside the cabinet, Then it's exposed, I want to test the performance of the system before and after and just see what we get. Obviously, expansion sewing expansion value.

Don't only do it because of performance. That's not the only reason, because, in fact, if you flood a coil and low ambient conditions, you'll actually get more capacity out of it. So part of the job of the expansion valve is to prevent flooding the coil prevent running liquid, boylee refrigerant down the suction line and damaging the system. So I don't know that necessarily under these ambient conditions, we're gon na see a huge difference with the system.

Once we put the DX v in, but it's just a nice exercise, so I'm going to go ahead and use my handy dandy test. Oh 6:05, eyes two of them to do get some readings from the system and just see how we're performing so. I'm just gon na use a half inch drill bit. I just do it by hand.

The nice thing about using a drill bit and duct board is that if you feed it in it'll, actually cool the duct board out and we'll end up shoving duct board into the system, which is a good thing all right. So I'm just taking those both at 6:05 eyes. The system is off so just seeing if they're you know in the similar in a similar range. If I wanted to really make I've already checked the calibration on these before, but if I really wanted to check, I would take them both and put them in an Airstream right next to each other.

But just so you know what you're reading, when you first open. This up, you've got dry, bulb, temperature, relative humidity percentage degrees, Fahrenheit TD, which degrees Fahrenheit TD. I always was wondering what is that temperature difference or whatever, but it actually means temperature dew point. So this is actually the dew point, temperature and then wet bulb.

So we have two of them and so they're compared to each other. Once we get the system running, we'll be able to use in what they call cooling heating power mode, we'll be able to actually figure out what the BTUs are. We got to enter the CFM, so I'm gon na look up the chart on this and kind of see where we stand. It says a extra key motor.

I believe I need to confirm that, but if it has an extra key motor should be pretty easy to calculate the CFM out. So you figured out it's around 1050, it's 350 CFM per ton, which means that we're putting out 31500 ish BTUs, it hasn't been running. Very long, so it's going to run longer to really see what we got, which is wire. Our supplier, RH is gon na slowly creep up the longer it runs, but we've got about a 20 degree delta T right now.

So you know from a just a summary glance at it. It looks like we're doing. Okay and we're gon na go ahead and check the charge outside and see what we've got out there as well, and that will give us a good baseline to compare to when we put the txt in. If you look here at this data tag, you can see that it says indoor TXV, subcooling, 12 degrees and metering device, indoor txt, we don't have a txt.

We have a piston we're putting in at exe because we're cool like that always bleed your hoses. People always lead here, physics, people, I always checked for seals inside the campus. Whenever I pull caps off all right, so the testify 50s are set to r410a. We've got a 41 degree, evaporator temperature 120 psi a ninety four point, three degree condensing temperature.

This system. I would expect it to be about your condensing temperature to about be about 20 degrees over ambient, which is about right, probably right about 75, maybe a little longer than that, but between 15 and 20 degrees or ambient, which is appropriate and that's our head pressure. Let's go ahead and check the sabrine set go, so our superheat is currently there. So cool is about three.

We haven't run real long in so we're gon na cool, let it run for five minutes or so and check again. Really our superheat right now at our current conditions, is pretty good. I mean it's about what we're gon na see once we put the TXV in all right, so we're gon na pump down the system as soon as we pump it down we're gon na put it under nitrogen pressure, I'm under the fray setting on my regulator. That way, as soon as we disconnect the fitting on the piston system, we can go ahead and hook the txp right up to it without contaminating any of the lines with humidity here, because if nitrogen be coming out and no we're getting in some thanks for easier Vacuum not getting crap in the system, so you're just gon na pump it down real, quick, all right, we're all come down to go all right, so we're gon na go ahead and recover the remaining refrigerant out of the system.

So we got a clean tank or recovery machine will bleed out the air, real, quick, good and then I'll open up the tank. At that point, you don't straight off the vacuum. We just got up recovered into the recovery tank, so I'm gon na hook it up immediately to our nitrogen tank and then put it to the braze portion and then turn that on okay. So now that's gon na pressurize the system with nitrogen, and so when we take it out and remove the piston to replace it with the new txb, it's going to be under positive pressure with nitrogen, but you got you got like six.

You guys is on right now, 6p. Is that what got a couple little bit of nitrogen - and I think it is it on - is it actually on actively yeah? So as we cut this sucker loose, it's gon na actually allow a small flow of that get into a scheme. It's good. This is a perfect.

This is perfect for a speed up sequence. Alright, so we are ready to rock and roll well snug in here it snug as a bug in a rug that is nitrogen, so see we got here. We have a 70 piston, which is what it said. It had a consonant link, which is good so with with a piston, which is something worth noting.

You see this. This two different pistons have different ceiling configurations. This actually has eight f1 CL on both sides, but on a heat pump with a piston, it flows one direction and then, when it flows the opposite direction, it unseats and the refrigerants that were out allowed to flow around the outside. So in one direction it's restricted.

The other direction it unseats and becomes unrestricted, which is kind of cool. They go by a lot of different names, each column, a curators, pistons, fixed orifices, sure there's some other names that I don't know. But when a piston, a lot of guys will say: oh the Pistons fail Pistons, don't fail, it's a hunk of brass. Now, just we can get clogged, so we can get stuff down the hole there or it can become impeded or stuck, but it doesn't fail.

Instead of trying to work in here because we're gon na have to run this straight into the valve, we're going to actually sweat in the copper as opposed to doing an adapter on the base. We're gon na use an adapter here, but we're just gon na sweat. Straight in I'm, just gon na we're just gon na cut it back here and make a whole new whole new piece all right, so we're gon na go ahead, and I show just got it back here initially, but we're gon na cut this line drier out. Whenever you remove a line drier, it's always better.

This is just sort of general knowledge, it's always better to cut it out and then to sweat it out, because when you sweat it out and you keep the dryer, you release whatever crap it's caught cleaning it - and this is one of the trickiest parts of doing These types of kits, because you have to add in obviously, if you're replacing it txt with the txt you've, already got a point to connect your external equalizer stir. Legalise ER is one of the most confusing terms in the industry, because people think it has something to do with equalizing the refrigerant, but it doesn't at all it's actually the pressure measurement point for calculating superheat. It just does it using the using the pressure of the refrigerant in the bulb in relationship to the pressure of the refrigerant in the actual suction line, so this is kind of tricky, but the best way to do this is to use a file use the edge Of a file use that to kind of cut into the copper without cutting all the way through the copper and then use a scratch awl to make the final bit use a scratch. Awl or some people use a nail set or different ways of doing it.

I don't like using a drill, because if you use a drill, then you can let shavings get into the copper and that's obviously a bad thing. So here we go. Let's give this a shot so to get a nice little groove in here. It's kind of hard to see, but that helps the keep the all from walking so buddy you see like if I tried to do this just on a regular copper line.

It's really hard when you put that groove in there. It really said it's really just for a place to hold the correct okay, I'm just gon na get it in deep enough that it can that it kind of yeah, so cuz I mean doing it on the actual curve. For the copper is this I mean you could do it, but this is a bit easier, safer and more accurate yeah yeah yeah yeah. We guess so we got the valve.

We got the air equip fitting here real quick. Then we have a flare assembly, an actual male flare and then you've got the chaplet fitting we're using the chat lifts for this. So we're going to sweat in the inlet here and you can see this has got an arrow on it. So it shows you.

This is the inlet I'm going to sweat that in and then coming out here we're going to connect in. Do I have to solder this little piece into the outlet of the valve, but you got to leave the teflon overhang off when you do that. Otherwise, you will melt the teflon o-ring and they will not see you so we're also going to use a little bit of nylon on the threads as well to just a nice assembly lubricant to make sure it's snug down like it's a teflon oring. That really does the work of sealing it in a traveling fitting one cool thing about this trap that they ship is.

It's got the different copper sizes right on it. It doesn't have holes in it, it just slides in and then you tension it, but it's pretty cool because in this particular case we've got three-quarter inch, copper. So this is the line that we go to and we know we've got the exact right tension all right. So I got the got.

The sensing bulb strapped on the side is where they show it. So that's where I put it, but technically it would. It would be fine on the top too. It's not gon na make a huge difference.

I've already got the Schrader core out of the external equalizer and we don't need a Schrader Karenna cuz. This doesn't have a core depressor, so definitely need to make the core get the core out. Otherwise it won't work. That's a common mistake on these.

I'm gon na go ahead and insulate the bulb now with this foam tape that they send with it this foam tape. Can I insulate that up and getting close all right, so we've got it in place now I don't have the chat, lift tighten down yet until we get it all sweated in, but we've got the external equalizer in we've got the sensing bulb in place with the The line, it's kind of made sure that it's in a place, that's not gon na rub against anything. Before we get done, I'm gon na take an you know, zip tie things together and make sure that nothing's gon na rub or vibrate check. All these tubes make sure nothing's gon na rubber vibrate, put foam tape in between and zip tie it together.

If there's anything, that's an issue now and a lot of the OEMs, they don't all necessarily insulate the sensing bulb. It's not a hundred percent necessary, but it does help. Give you a more accurate superheat, and this in this exercise we're wanting to get as accurate as we possibly can. So we just got to finish sweating this in which we're going to do now.

We're gon na put the line dryer here close to the air handler, which is the optimum location, to protect the new expansion valve. We actually have nitrogen blowing out the end here right now, because we've still got the nitrogen on the braise setting and I've got the one-way filter dryer, because it's not a heat pump. This is straight cool. We're gon na mount in and finish this up and then we're gon na be ready to do a pressure test.

Standing pressure test do some bubbles, especially on the on the threaded connections. We get a good visual inspection on all of the sweat joints to make sure that they've got a good fill it on everything, and then we will go to doing our evacuation. One 54.3 on the section is what I'm primarily going to watch we'll be a little bit of Equalization fluctuation with temperature, but should be, should stay right in that zone, so we're going to let that hold for a while standing pressure test bubble test. The actual threaded connections and see what we get all right, we're looking good have to do the just: let it steam for a while and see how it so we've been holding now at 154 for 20-25 minutes or so, and we're ready to go ahead and pull Our vacuum, so I got ta, attach the cord remover tools on both sides.

That's our great big hoses vacuum rated hoses right, ground gage, but I'm gon na do that. Do that? Alright quick pause here, so we do not pull the vacuum through the gages, even though these are great set of gates up. Just all manifolds have some restriction in them and we don't want to add that restriction to our vacuum. So our vacuum is we're not going to remove the gages we're gon na keep them here, because we need them for when we're ready to set the charge, but the evacuation.

The vacuum is going to be pulled directly hoses to the system through for removal tools. So removing all right, so once we get to 300, then we do BDK test er decay rate, the rate at which it's rising, which is very low. Definitely within the acceptable range okay. So we got the trainer pins back in.

We got our gauges hooked up right now. We got to set the charge, so this particular unit now that we have the TX being installed, is calling for a 12 degree, sub cool which it shows right here on the data plate. So this outdoor unit was designed to have a TX v that air handler did not have a TX p had a piston. We switched it to the TX v and we're going to set the charge with 12 degrees, so cool tighten up the service valve caps and then here we have the strike tank recovered refrigerant that we got from it.

So right now we're at 5 degrees of sub cool this one here 5.4, and we want to get it right. At 12, we're gon na hook up here open the tank up, bleed our hoses out just to clear it of any contaminants. We have so again we're at five point four, and we want to see if we can we're going to get that 212. All right, so our test, Oh smart, probe, clamp the 1:15 eye is showing outside.

We have a sixty five point. Five read section line temperature. Now we're going to check it inside and see what type of difference we have. Cuz we've got a pretty good distance and with super heat on an expansion valve, the expansion valve sets the superheat at the air handler not at the condenser, so we're gon na check it in sight to again so our return temperature is 75 degrees.

You can see our section line temperatures dropping well below what it is outside, which means that we do have some temperature rise on the section line from inside to outside, which accounts for the fact that we have a high. If super8, let's see what we're doing. As far as delivery capacity goes turn on Bluebird 6:05 eyes, so this right here is the section line temperature. This is the return.

This is the supply. So if you had a twenty one degree, delta T right now or Turner is fifty one percent. You point fifty five point: six as far as that goes that looks pretty pretty standard. We're gon na go to cooling and heating power.

One thing to note is at this stage we do have better capacity than we had before. Hey. Oh, it's good here. Delivery capacity is good.

We have forty saturation one step in Tumkur, fifty-four yeah, what's up yeah 14 degrees superheat, it's not definitely not outside a range is for these systems. You know, and again we haven't run that long. Like 14 degrees superheat, I'm not gon na adjust it. You know.

So one of the questions that came up with this with this kit is: should you start adjusting an expansion valve and my answer to that is: don't do it unless you are well outside of range. In 14 degrees Subramanian, in this case now we're down to 13, is it's just again. It just hasn't run long enough at this point for us to make that determination, everything is within range. The delivered capacities within range Delta, T's within range selection, had everything that we're looking for is within range.

It's setting a good superheat here. Yes, it is higher outside, but it's not the th C's job to set the superheat at the outside. It sets it at the inside. You see an hour down to 50/50 2.9.

It's all! It's all looking looking really good, so our sub cool right now is what the sub cool is twelve point: four: okay and the target on the condenser, because the condenser says that it should be at exp. The target at the condenser is twelve, so again we're gon na let it run another 10 minutes and just make sure. But at this stage everything is looking really good and the advantages of at exp. Are you control your you control your capacity, the pounds of refrigerant that are entering the evaporator over a much wider range of conditions, and you take advantage of the ability to have a set so cool and with the set sub cool? That means that you're going to be closer to the coil temperature you're, already you've already dealt with a lot of that heat energy.

That's in the refrigerant you've already dropped that down the condensing temperature. It's efficient linked. I mean you're gon na operate efficiently and safely for the equipment over a wider range of conditions, because it's not gon na flood. The compressor.

It's not gon na cause those problems, so everything everything I'm seeing here looks good. Let's do one final test here of we've got as far as capacity yeah we're still at 33,000. So I would strongly encourage you to consider looking at the danfoss Universal tr6 kit, it's a great kit as great instructions. If you did need to make an adjustment to your superheat, it tells you exactly how to do it and how many turns to make what adjustment I would suggest getting r410a and in our 22 kit and either having it in the in your shop or on the On the trucks in case you're, in that situation, where you need a good quality valve that will work on almost any residential in my commercial application, so i'm brian or with hvac school thanks for watching and we'll see you next time.