All right today we are going to be working on this uh region because uh, it's got a refrigerant leak in it and we're gon na need to find where the refrigerant leak is and then probably quote to the customer to repair it. So so we've got a small multiplex rack here, we're dealing with this one right here. So what i did is i opened up the doors down below to get the unit calling and then i'm going to come up here and turn off. The compressor put my gauges on it turn off the compressor, equalize out the gauges and then go downstairs and try to find a refrigerant leak.

Now we had another service tech here recently and he topped off the charge so just to get him going so now we're gon na dig into it and figure out where the leak is so this one has a schrader port on it, but this one right here Has a packing on the valve and you want to loosen the packing before you actuate the actual valve. It just saves the life of the valve um. So you can see we have 147 psi on the high side. It's not 410a, but absolutely doesn't matter right now.

It's 404. and we have 66 on the low side. Now the compressor is not running, so what i'm actually going to do is equalize out the gauges open them up. So that way we have equal pressures that way it's easier to find a refrigerant leak.

Okay, um make sure everything's nice and tight probably should go in yeah, we're good all right, so we're there now we're going to go ahead and go downstairs and do a leak check and try to pinpoint this bad boy all right. Today we are using fieldpiece's new leak, detector, it's the dr82 infrared and check it out. It has a lighted tip, so it lights up if it finds a refrigerant leak. So let's dig in there we go.

I dig that tip leak. Detector, oh yeah, for sure i like it, because if you can't hear it, you can see it flashing on you, so we're going to get some soap bubbles back in that guy right now, all right! We're going to continue on to this side, see if there's anything going on over here. Doesn't look like it looks like this. Coil is probably okay, even though it doesn't look the greatest check over here.

Yeah we're doing good all right. Let's get some soap bubbles on this guy using some big blue and it looks like we've already got it right. There, yep all right and while that is abrasible leak, the coil's trash, so we're going to go ahead and quote a new evaporator all right. I leak checked the last coil that you guys didn't see nothing in there.

So it's just that one coil um made sure these guys are closed and we're gon na go ahead and turn this guy back on and put it into normal operation and then we're gon na submit a quote and come back all right. We are back today the customer approved the repair, we're going to change an evaporator coil um, we're going to start by pumping this guy down so come over here to the receiver and we're going to front seat the king valve and then we're going to get changing The coil out this valve right here has a packing, so you want to make sure you loosen that packing before you actuate the valve itself, so it doesn't take much just a little loosen right there and then now we can go ahead and completely front seat. This now i've got my high side gauges on the other side, so the refrigerant is uh basically going to stop at this valve. I get a true high pressure reading at the compressor and uh yeah we're gon na wait for a clump down, then we'll change the coil and then change the dryer.

Now the refrigerant is stopping at that valve right there that i front seated right and it's not allowing it to go through the rest of the liquid line, but my compressor keeps pumping until the suction pressure gets low enough, that it shuts off, and it kind of Looks up yeah, it's kind of looking like it's getting a little bit low, see how it's going to short cycle, see it's turning on and off, because the pressure controls a little out of adjustment, we'll make sure we adjust that um, but anyways. The refrigerant flow has stopped it's pumped down into the receiver in the condenser and we are safe to open up the low side. Now let atmosphere into the system, and then we can do our repairs downstairs. So we take off the low side hose.

So that way we can relieve the pressure because there is going to be refrigerant pressure that would build up in the system when i'm trying to braze downstairs - and we don't want that. So we open the low side to atmosphere and then we can do our repairs and then that way, when we're brazen and stuff like that, the pressure buildup that potentially could happen because of oil or whatever in the system, would have a place to escape and wouldn't Um, you know compromise my braze joint, so all right. So what i do is i come in here and once i get it done, i just cut these guys cut this guy cut the power head undo, the screws pull the whole coil out and then we'll worry about. You know figuring out how we're gon na put it in in a minute.

So so we have to unsweat the old txv we're gon na. I i have a new txv, but it's different, so i'm hoping i can fit it in there. I didn't know it was this style. I thought it was just a standard txv, but we'll make it work.

Trust me from experience. You want to cut these brackets because they're really big and they get in the way and impede the unit from draining. So i always cut them before i put the coil in there and you can see i just kind of mocked it up in there and i cut the bottom brackets, but this is the txv that i have and i have to. I can fit it there.

No problem, but getting the 90 that the liquid line the quarter inch to come down and connect to that is going to be a chore. But let's see what i can do all right, so we got ta do all kinds of stuff to make this work. What we're doing is pulling this little stub out of this t right here. If i can carefully okay and then what i did was i unsweat that little stub so that way, i'm gon na have room to put this in there and then just make a little stub to go between the two all right.

So that's about how it's gon na be i'm gon na go ahead and sweat it in real, quick. It's super tight in here and then we'll worry about getting this one taken care of all right. I ended up doing the top. I got to straighten that line out a little bit in the bottom.

We got it all set up, so i'm going to braise everything and i just got to watch out for those electrical lines back there that's going to be tricky; okay, yes, okay, okay and there's nothing pretty about these things, and you know it's never perfect, but all Right, let's uh inspect them with the mirror, make sure everything's good and then we're going to try to put everything back on all right. I went ahead and insulated that it's not perfect. You know you can only get so much with these things. We're gon na try to put the cover back on and the sensing bulb and everything, but we're in it's uh got good braze joints, so we'll jump on the roof.

Now, before you start putting everything away, you want to make sure all the fan, motors work and everything there's nothing worse than getting all the shelves back in and then fan motors stuck. So we're good, we'll leave this guy running, so the solenoid valve is calling and we'll get up onto the roof and start the evacuation right. So i've said this a bunch of times. I love using the squirrel and catch all, but i like the flare, because if you look right here, i didn't have to bring my torches after this repair.

I just come up here, loosen up the flare nuts put the side glass on this guy and go to town and then pull the evacuation. But it's really important too. When you're doing these flares, i keep a steel brush and try to get any crap off of there. So that way we get a good contact with the flare nut and then, of course, we're going to take a little bit of nylon just a little bit and just lubricate the surface and lubricate the top of the flare nut.

So that way it doesn't bind when you tighten it up, so this guy is loose now get in here that guy's loose and this guy's loose. So we'll open these guys up. Take this guy apart and then disassemble it put the sight glass on it and then put it back in and then we're gon na get started on our evacuation. So just the tiniest drop of nylog and that's on the outlet of the dryer and then now we're just gon na screw this guy on and remember nylon.

It doesn't harden so it really just becomes a lubricant helps you to get it nice and snug, and then it really does its magic on these flare nuts right here to make sure that they don't bind so we're going to take a little bit of nylon. Just put it right here and then it's just there so that way, the flare nut right up here doesn't bind and twist the copper and then we'll do the same thing down here. This is the tiniest bit right where the flare nut is going to hit spin. It and then now we're gon na put the dryer in all right, so we got the uh dryer installed in the right direction.

Uh now we're ready to get over there and pull our evacuation. Let me explain this. This is not an ideal way to do an evacuation, because i am going to be pulling through my manifold gauge set okay now i realize that the best way to pull an evacuation is to use large diameter hoses and not to pull through a manifold, but there's Times when pulling through a manifold is necessary and or you know it's just easier and let me explain, i am only pulling down on the low side. Okay, the system is in a pump down mode, meaning that there's refrigerant in the receiver.

You are never going to obtain a perfect vacuum, especially on an older system, because the receiver valves uh inside the compressor, there's always potential for very small leaks by scroll plates by um, not scroll plates, but by the inside of the the compressor and by the valves. At the receiver, okay, so in this situation is one of those things where i'm gon na say it's gon na be okay to go ahead and pull through my manifold. But you just have to understand that the micron reading on the manifold is not necessarily the true micron reading of the system. There's ways that you can watch the decay and stuff okay.

Today, i'm going to be using fieldpiece's new vpx7. This is their new 10 stage. Dual uh, i'm sorry, 10 cfm uh vacuum pump. Okay, i've been using this for a while, and i finally got the all clear to go ahead and talk about it.

Okay, um, they redesigned the pump. It's actually six pounds lighter than the vp85, which is the previous pump. So that's pretty cool um. We have a gas ballast over here.

As usual. One of the things they did add is a removable cord. Okay, so you can actually pop this guy off. If you needed to for storage reasons, okay um put that guy back in and it snaps into place, um and then, of course, you've got your tree right here.

With 3 8, 3 8 half inch quarter inch. You have your oil port right here and, of course, you have the on the fly. Oil changes where you can just simply flip the valve drain, the oil which will do that here in a few minutes, and you have uh your exhaust port right here of which has a connection if you needed to you, could put on a hose and run this Outside of the building uh, i personally have never had to do that, but in certain instances like when i used to work at hospitals and stuff like that, maybe you were in a sensitive room and you didn't want those exhaust fumes. You know um, so you could pipe that into another area, so that is pretty cool um.

This one does have a dc motor and by making it lighter, they put a different motor inside of it. It has the slow ramp up like it's always had so we'll turn it on and it slowly builds up and then boom then turns on and we're running at. You know normal by now, so it just took a second. So what we're gon na do is uh.

I'm gon na actually continue to pull an evacuation on my manifold just to make sure my hoses are pretty tight. Another thing to understand too, when you're, using a manifold when you're using well i'm not pulling through the high side, i'm only pulling through the low side, but these hoses are not leak-free they're not meant for an evacuation. So again you have to understand that when you're trying to pull a vacuum - because it's not going to be perfect, so i'm currently going to pull this guy down. I don't expect the evacuation to go extremely low on just my manifold set right now, but we'll just get it down all right and then we're going to go ahead and open this guy up.

But i'm going to go ahead and open up the gas ballast and you actually have a light to tell you now so we're gon na go and open this guy up and we're pulling now through the system. I just opened it to here and we're pulling uh with the gas ballast open so that we were saving the oil and we're going to wait till it gets down and then we'll close the gas ballast. Once we get down into micron readings all right and while i'm waiting for the system to evacuate since i have the receiver pumped down, i went ahead and heated up the receiver with my heat producing device not to exceed the soft plug temperature or anything and check The liquid level and our liquid level is good. It's actually a little bit high because we had another tech out here that probably put a little bit more but the liquid levels right here so essentially because there's liquid refrigerant in here, if you heat it up very slowly with a low heat producing device, you can Run your fingers up and you can actually feel where the temperature difference is where it starts to get warm or hot, is where the vapor is at.

So this one is right about here, so cool, so we're good on that. So we know we're not going to have to add any refrigerant so again we're just waiting for the evacuation. Now all right, this system has a head pressure control valve and because it has a head pressure control valve it's up in here. It requires extra refrigerant.

When that head pressure, control valve starts to flood the condenser, and it does that in low ambient conditions right now, it's about, i don't know 62 to 65 degrees outside. So more than likely, when this system starts up, the head pressure, control valve is actually going to flood the condenser and the reason why it does that is to help to maintain a pressure differential across the expansion valve. Okay with that being said, you have to make sure that your system is charged properly. Now this system has a sight, glass and a sight.

Glass is a good indicator of a full column of liquid going to the expansion valve, but the excite glass won't tell you necessarily if you have the proper flooded charge now, if you came out on the coldest day of the year and check the sight glass and You got to clear sight: glass, then sure you would know you had enough gas in there, but that's not very convenient to come out on the coldest day of the year to charge the system right. And how do you know it's the coldest so with that being said, a couple different ways: you can lean on the factory the factory. Actually, if these people right here tell you that it's nine pounds of gas, this is a kyrak rack um, but the easiest way to do it is put the maximum amount of refrigerant in there. Okay, now you could also calculate the flooded charge using sporland's method.

90-30-1. Um and that's actually how the factory came up with the nine-pound charge: okay, but when you're in the field and you're topping off the charge, it can be kind of tricky. So that's where marking it after you've added refrigerant and put the proper charge in definitely helps. Okay, so in this situation my receiver's pumped down right now - and i heated up the receiver with the heat producing device that doesn't exceed the soft plug temperature, because that is a safety blow out right there.

Okay, and what i do is i run my fingers up. The receiver and the moment that the the receiver gets hot indicates that that's where the vapor is and that's the separation between the liquid and the vapor. So this particular one right now is right at the factory charge level, because i did have another service tech here. Charging the system, and then i came out and found the leaks and all that stuff.

Okay, so we know that we have the right amount of refrigerant uh for the system to flood when it gets cooler outside. So we're good to go on that and we're just waiting for the evacuation to finish up all right. At this point, it's pulled down to what i consider to be an acceptable level for a pumped down system. Uh i dropped down to about 500 microns, and then i rose back up to about 8.49.

It's slowly rising 8.50 again, because this is a pumped down system, you're, never going to obtain, in my opinion, a perfect vacuum: okay, because you're pulling against refrigerant still in the system, um and uh. You know it's always hard to, like. I said earlier pulling through a manifold because you've got potential leak points everywhere on there, so we're gon na go ahead and uh turn everything off. I've got to connect this low pressure control back into the system, because that was a schrader.

So i did remove that to be able to have full access to the valve, and now that i put this guy back on, i have backseated this uh valve right here. We're gon na go ahead and pull an evacuation on this right here, because it's not open to the system yet so that'll pull into the uh the the low pressure control that we're not putting air into the system through that source right there all right now. It's very important again. This system is pumped down.

If i tried to open the high side, all the refrigerant would leak out of the system, so there's refrigerant sitting in the high side sitting right here, so we're only pulling an evacuation on the low side. The system downstairs they're, already cooking and jamming in there, so i'm not gon na really go down there anymore, but it's kicking butt down there. Um i had someone uh do a leak check, real, quick down there, we're looking good we're gon na go ahead and do a leak check up here at the dryer, so i'm gon na get the leak detector but yeah it's kicking butt all right! So we're gon na jump in here i just have it on high, which is where field piece recommends that you use it. It's super light and compact too super nice feels well in your hand, we're just checking my uh, my flare nuts, to make sure that nothing funky is going on there.

That's cool see it's not picking up the nylog, which is a good thing, we're not seeing any leaks, all right, we're good to go nothing and then i'll come over here and i'll. Show you guys just for reference. How this thing reacts when it does see a leak ever so slightly, cracked that and there you go, you can see that it's picking it up right there and then you get a readout on here. Now it's not a parts per million readout, but it's just a numerical readout, but i like that.

I really like that, because that's one of my issues, i'm kind of hard of hearing - and you know it's difficult with these things um this thing has a usb charging port on it. Usbc so uses the same charger as most phones, which is cool and uh yeah. Nice nice little leak detector. Here i turned the rack back on, so i'm going to take this opportunity, while everything well once everything starts running i'll check, all the other side glasses, but i think we're good we're going to go ahead and take our gauges off of this guy.

The box is actually almost already down to temperature down there. Um yeah we're looking good running clear side glass. So i'm a happy camper, not too difficult right. We just had a service call.

Well, another technician went out on a service call where he had to put refrigerant in the the system, and then i went out a couple days later to find the leak found. The leak got it approved, went back out with a replacement, evaporator coil. So we do a lot of these things and you kind of have to learn that you know, even though that leak looked repairable, you look at the rest of the coil and these coils they just rot out, so we really push replacing those coils versus you know. Brazing on them, just because we find that once we braise a leak and you get that area hot, you tend to see more problems pop up around that area, so the braze joint next to it and the brace joint next to it.

They just get rotted out. So um, but cool thing is, is we got to use some new tools inside this okay? So we have field pieces, new leak, detector, okay, i use the uh dr82 right and that's the infrared leak. Detector they're also releasing another leak. Detector and i've got it written down, it's the dr-58 and that one's the heated diode leak detector.

So you have your choice between the two i've gotten my hands on both of them and they both actually work. Really awesome. Um super easy to use. One of my favorite things about the leak detectors is they're very intuitive right and when i talk about tools, i love to figure out how intuitive they are.

I'm a i'm a big fan of just picking up a tool and trying to figure out how to use it and on the leak detector. It's super easy. I mean there's really not a lot to try to figure out. You've only got a couple buttons and it's super easy to scroll through changing the modes from high medium low and then turbo mode, super simple and then that heat or that uh that tip on how it lights up.

I love that feature because again, when you're hard of hearing or you're working in a room, that's loud or something like that, it's great to have that display and the lighted tip when you come across a leak. Okay, also, we got to use their new vacuum pump. They're actually coming out with three new vacuum: pumps too they're coming out with a six cfm and eight cfm and then a 10 cfm. Now i have the 10 cfm, so that's the vp x7.

Okay, that one's awesome and the cool thing again about the 10 cfm one is that it's lighter than their existing pump. The vp85 right now and that's a trip, i've loved the vp85 and been using that for a couple years now. So i'm super stoked to to add the 10 cfm to my lineup, now understand something when you're using vacuum pumps - and i explained in the situation in this video too, your vacuum pumps are typically limited by your hoses. Okay, rarely are you ever gon na uh on on the systems that i'm working on? Am i really gon na need a 10 cfm? I mean occasionally, when i get on my big acs that i work on.

You know that's really going to come into play, but using quarter inch hoses, you could have a two cfm because you're not going to get. You know like half a cfm a flow through a quarter inch hose okay, so understand. You know that when you're buying these pumps, you definitely want to look at getting larger diameter hoses and use them as much as possible. Now, in the situation that i was in, i was pulling on a pump down system.

It wasn't going to be a perfect evacuation in general, but if you have a fully open system, that's open to atmosphere and you really need to pull down on it. Get you the 10 cfm pump with some large diameter hoses and you are going to see a big time. Change also remember to remove the schrader cores and anything like that. If you are going to use your manifold gauge set, which is not ideal, but it does work and use the quarter inch hoses, you want to take out any restriction in the hoses, so those little schrader depressor tips that they put in the end of the quarter.

Inch hoses to push down on traders, you want to pull those out because those are another point of restriction. When you're doing your evacuation and again even pulling out all the little quarter, inch schrader depressor tips and pulling out the schraders you're still going to be limited by the diameter of the hose, which is quarter inch. It's going to get minimal flow. So you always want to go for bigger hoses whenever possible.

Okay, you know, and again it's you know we're not always perfect. We don't always get everything perfect right. We can't always pull a perfect evacuation or anything, but the the biggest thing is is that we understand the limitations and, what's causing the vacuum to slow down? Is there moisture in the system? Are you still pulling refrigerant out of the compressor oil that kind of stuff um? You know if you start to notice your evacuation stalling, like do this little test, if you guys are ever pulling on a system that you made a repair on right and uh you're pulling on the compressor oil all right, and you think you have your vacuum. Let's say you get down to 500 microns and it's slowly rising, grab the compressor and agitate it just shake the compressor.

Okay, and what you're going to notice is refrigerant's going to be boiling out of your or you know, coming out of the oil as you agitate. It and then your micron level is going to rise. Okay, so everything comes into play when you're pulling evacuations, especially on older systems. Okay, i love these videos where people show like a perfect vacuum in a minute and a half.

You know, and it's amazing they're not pulling on an old compressor with refrigerant or moisture in the oil they're, just pulling on a dry line set okay. In reality, it takes a lot longer to pull an evacuation, especially on older systems anyways. So um we got uh the system back up and running the customer was happy and all was well. I really appreciate you guys making it to the end of the video.

If you haven't already please check out my website. Hvacr videos.com also uh go to fieldpiece instruments. Website uh and check out the new tools. They will be releasing very soon, if not already, and we will catch you on the next one.

Okay.