All right, um we're changing this contactor right now, and you know this is one of those weird things where it's a carrier: oem contactor that has screws in the top and lugs in the bottom. So that's not a normal contactor that you go and buy from the supply house, but i've shown this before there's a trick. If you buy a contactor with lugs, the lugs actually come out below the lug. When you pull this top screw out, there's a screw when you pull the screw out, you can take the lug out and it receive the normal screw from there.

Okay, so we can still have lugs on the bottom and screws on the top get it. This video is brought to you by sportlin quality, integrity and tradition. Today we have a ac that is not working right. We had some service techs out here doing a pm.

They shut the unit off because it wasn't working so i'm going to come through this and diagnose it and figure out what's wrong with it. So, let's get into it all right. I've got my electrical control panel opened up we're gon na check three phase power, because this is a three-phase unit, so we have 211, we have 212 and then we have 212.. So we've got three phase power coming into the unit.

Let's go over here to the thermostat board: we're going to check for 24 volts from the transformer low voltage transformer right there, sending 24 volts to the thermostat. Now they do have internet controlled ems system here. So sometimes those can be a problem um, but my technician said: the unit was running it. Just wasn't.

Cooling so y one to c is no voltage. That means that the thermostat is getting power through r and c and the thermostat lot or the thermostats logic is not turning it on, but it could just be that i just turned the disconnect switch on and it's going to take a few minutes. Okay, so again my technicians told me that the unit was running, but it wasn't working right. So i'm going to go ahead and jump out the thermostat, because i have a feeling the uh thermostats just got a delay or the energy management system's not kicking in.

So i'm gon na jump it out and then we're gon na see. If i can figure out what my technicians were saying what's happening all right, i jumped out the thermostat right there, r to y1 and the unit turned on, but then it shut off interesting and it just started again and then it turned off. So it kind of sounds like it's going off on. Maybe a pressure control.

I would think maybe a low pressure control, because the condenser fan motor is running, but it could be a high pressure control too. So we need to figure that out where's the problem at so we can go right here and we have low pressure and high pressure, so we can figure out if one of those is the problem. So if we go across high pressure control, we have no voltage meaning the power is passing through the switch okay. So let's go ahead and go to the low pressure switch.

So if we go to the low pressure switch, we have 25 volts and it's gone now. It's passing through the switch and then it's open so we're going on and off on low pressure right now, contactors pulling in and out and if we look at that contactor it's kind of burnt inside there too, which isn't good. So it sounds like. Maybe it's been going on and off on low pressure for a while now, so we're gon na go and power down the unit.

Okay, and we need to put service gauges on this guy to figure out why it's going off on low pressure? Are we out of gas? You know who knows so, let's get into it all right got the compressor section opened up nothing too crazy. You don't see any big oil stains or anything now um, i'm! Turning on my jaw, blink probes, uh the field piece, doubling probes and i'm opening up measure, quick and notice that i don't have them connected anything, but we see one psi. It's so important when we're using digital tools doesn't matter what brand that you always make. Sure they're zeroed out before you put them on the system, if you simply put these on there without turning them on and then turn your phone on your pressures or your readings could be skewed because of issues like this.

Now i drove a long distance and went down in elevation, i'm i'm well at sea level versus where i was the last time. So it's plausible that these probes need to be zeroed out. So all that we're gon na do is hit zero before they're applied to the system boom done. Okay, so um we're gon na go ahead and apply the probes and then put all the temperature clamps and everything on there then we'll fire it up all right now.

In order to profile measure quick, we need to know the tonnage of the unit. So if we come over here carrier uh, this is going to be a three ton unit. Okay, uh, it's one less than that number right there, the four! So it's going to be a three ton. Sometimes you can come over here.

They'll have a charging chart they'll, have it on there too tco4 three ton charging chart that charging chart is basically going to be um target superheat, because this is a fixed, orifice metering device. So if we come over here, i can already show you there's a problem here: we're probed and look at. We have 189 psi on the low side and on the high side. So doesn't really look like it's low on charge.

It's always a possibility, but we need to turn it on. You can't tell the charge just from the static pressures you do have to turn it on to to make sure this isn't going to tell us anything because remember those pressures are going to change depending on the temperature of the indoor coil and the outdoor coil. It could be really cold outside those pressures are going to go down, it could be really hot. The pressures are going to go up okay, so this doesn't tell us if it's low on charge yet, but it does make me concerned because if it was low on charge, i'd expect those numbers like if it was out of gas or something because it's shutting off Immediately, i'd expect there'd be no pressure on the low side.

So, let's start let's uh profile this guy system info, so we're gon na go over here to package unit. We're gon na go to right here. We're gon na go three ton. We're gon na go 13 to 16 sears fine.

We need to change it to a fixed, orifice metering device. Everything else is accurate. It is a 410a system. So at this point, let's go ahead and turn it on and see what happens turns right on suction pressure drops drops drops and the unit turns off immediately.

That's interesting! So look at the sub cooling when it was running. I mean it's not giving it very much time to even run, but look at that. Turning right off. That's very interesting! Okay, so i'm actually going to hold in the contactor.

So we can kind of see what happens here. So look at that sub cooling notice. It's about 17 degrees, it's not really dropping too much okay, but look at that suction pressure. All right to me.

This screams that we have a restriction in the system so notice that liquid line temperature 60 degrees. That's very interesting! Why would we have a 60 degree liquid line temperature when it's 78 degrees outside so something's going on here? That's very odd. Look at that liquid line temp as it drops and drops and drops. Let's turn it on again watch that liquid line temp 61 degrees.

62 degrees. That's very odd, so it's not good to run these compressors at a really really low pressure like that compressors! Don't like it, but i'm thinking we have a restriction somewhere in the system. We need to figure out where, potentially that liquid line is very cold, so i'm suspecting the liquid line being a problem. So being that, i, where i have my liquid line, temperature clamp is on the outlet of the filter.

Dryer, it's back there. It's kind of hard to see all right, it's right there that top one. What i did was, i put another liquid line: clamp on the inlet of the filter, dryer and now we're going to get a comparison or a differential between the outlet temperature and the inlet temperature of the liquid line coming out of the condenser going into the dryer. So we're checking to see if we have a restricted liquid line, filter dryer, all right, we're going to get ready to turn this guy back on and what i am going to do is actually jump out the low pressure control.

So that way the system runs and i will control it via the disconnect that way. I can hold the camera and show you guys what our temperatures are all right. So i took my red jumper went across the low pressure switch so now the low pressure switch. Won't close this guy's right here and then i don't have to worry about holding in the contactor and what i did was i changed to the tool view.

So that way we can see the different liquid line, one on the top liquid line. Two and we'll see the difference across the dryer when it turns on and there we go now, let's watch and see what happens: 84 85 degrees on the inlet of the dryer 67 degrees. On the outlet of the dryer. We have a restricted liquid line, filter dryer 81 degrees, going in 62 degrees going out, so we clearly have a restricted filter dryer now i can actually feel it with my hands, but the cool thing about digital probes is, you can prove it and you have a Record of it, okay, so for some reason this filter dryer is restricted down in here now this system really hasn't had a lot of work done to it.

It's an oem original compressor from 2008 and i'll be honest with you that filter dryer looks brand. I mean looks like it's from 2008, too um. It looks like this strap. There was a plastic panduit, strap holding it on that strap's broken off, but that dryer has paint on the braze joints.

So we've got a restricted filter dryer. Why did it plug up? Is the question now this is 410a. There is poe oil in here, so it's a possibility that we have some sort of contamination in here, but we have to think again. I installed this unit in 08 and really haven't had to do much work on it.

Maybe some contactors here and there, but i'm kind of worried that we might have damaged oil because again, i know the service history on this guy and uh. It does get extremely hot where we're at um, we are out in the low desert, uh coachella valley. So you know it hits 120 degrees in the summertime um. That puts some strain on these units for sure.

So do i want to just change a filter dryer or do we want to look bigger and try to figure out why the filter dryer could have plugged? Now it's hard to say because the system's not operating, i mean it could have been prolonged. Condenser fan motor failures, but it has a high pressure control right and that is an oem motor. But it looks like it has been replaced that doesn't look like it's from o8, but it is oem. Condenser is maintained on a regular basis, but i mean during covid you know the original, lockdowns and stuff.

There was a lot of time that they weren't doing preventative maintenance at this location. They are now um. So what caused that filter dryer to plug up is the question all right: we're going to make this repair so i'm getting set up for recovery. I went ahead and hooked up my manifold gauge set because it's a little bit easier to recover with i cracked my discharge line, cracked, the process port opened the recovery and left this one loose and we're purging the lines right now.

So there we go so we've purged that so now we can open this, but before we do that, we need to zero out our scale. Okay, so scales connected hit zero there we go we're zeroed out. So now we open this and everything we add to this tank. This is a vacuum down tank, so we're gon na, let it suck in as much as it can now.

I did put ice in there and i'm going to put a little bit of water too, because this is 410a cool down. The tank keep the pressures from getting too high it'll slow down the recovery, we're also using large diameter 3 8 id hoses from the gauges to the machine from the machine to the tank. So i'll put a little water hook, this guy up and then hit start and get this recovery done now. I don't plan on reusing this refrigerant we're going to go ahead and replace it, because we don't know what the contaminants are.

So this is very interesting um. The recovery machine shut off because it pulled into a vacuum. It does an auto shutoff feature, but i only recovered a pound and maybe two pounds uh. The total charge on this is like six or eight pounds.

So that's interesting. I don't see any signs of oil, but we better do a leak check on this guy before we make any major repairs here, so we're gon na pressurize this with nitrogen and see if it passes a pressure test. I don't know if someone tried to let refrigerant out because of the i i don't know you know i don't know what's going on here um, so this is interesting, so yeah we need to put some nitrogen in here and see if it passes a pressure test Before we go any further, all right, there's still a little bit of vapor that, even though it pulled down into a vacuum, the vapor boiled out of the oil of the compressor. So we're going to use that as our trace gas got some nitrogen right here.

We're going to go ahead and put this into tightness test all right. One thing, i will say was um. I was thinking about it when i took off one of these guys it was missing the gasket one of the cormax fittings, so that could be a problem. I don't know you know we'll, go through it and see um.

So now we're going to uh, add refrigerant to the high side. Let the pressure build up and then we'll do a leak check on the system. Once we get it all. You know up to where we need to get all right, i'm using the field piece manifold and it has a pressure test feature.

So you got a tightness test and i've entered it and what it does is. It starts a timer. You can also put on a suction temperature, clamp and it'll temperature, compensate to tell you but anyways. The point i want to try to make is i've been testing for eight minutes now and we've gone up just about one psi, it's kind of dancing around.

I don't think we have any leaks. I think that one of these cormax fittings was leaking and let me find my caps, let's see if they had gaskets in them. These are my caps that one has a gasket that one has a gasket. They both have gaskets, but that doesn't mean that they're going to stop pressure, so i think again look at we're at 1.1 psi, so it's rising and i'm not adding any more nitrogen.

I mean. So i think that the system uh was just leaking from the cormax fittings because i'm not seeing any signs of a refrigerant leak, so we're gon na. Let it run for a few more minutes, but i'll probably end up just pulling the nitrogen and making the repairs that i need to make all right. I suspect that the oil is uh compromised inside that compressor.

So i actually have an oil in my van we're going to go ahead and weigh the amount of oil that i get out of the compressor and then we'll put that exact amount back in and then we'll finish with the repair. I'm cutting a bunch of stuff out, so i'm going to pour the oil out of that guy. Real, quick and we'll get a look at what it looks like okay, my scale is zeroed out that actually doesn't look that bad. It doesn't look bad at all.

All right, actually it doesn't look bad. It doesn't look bad at all, we're still going to replace it. We're still going to put in so we weighed 15.75 ounces, so i'll make sure i put that exact amount of oil back in that compressor. We'll put it back in we'll pipe it in.

I had to cut everything because i was cutting out the cormax fittings anyway, so i figured i'd just pour the oil out so i'll go grab the oil for my van we'll get it put back in there and then we'll get it all brazed back together. We're just getting everything brazed in we've got the nitrogen flowing. So all right we're just about done. Those are in we're going to do a pressure test, and then i got to do this one right here with uh silver solder, all right we're currently in a pressure test right now, um we lose point.

Uh looks like negative one psi in about seven minutes, so we're gon na watch it a little bit longer make sure i've got uh, big blue soap bubbles all over everything and i'm not seeing any leaks so we'll watch it a little bit longer make sure there's Nothing else funky going on and then, if uh, if everything goes good, then we'll start the evacuation for the life of me. I cannot find any leaks all together. It kind of went back and forth and it came back up. It went to like one psi that it lost, but then it rose again so we're getting like a breeze coming through.

I went ahead and just rinsed everything. So now it dropped significantly in pressure, but i rinsed off all the soap bubbles cleaned the condenser because it was kind of dirty over here. This isn't a double row, but it was just really dirty up here in the top, so give it a good cleaning. We can clearly see through it now i'm going to go, get a contactor we're going to go and replace that contactor that's burnt and then we're going to get the evacuation running on this guy.

All right, we got the vacuum pump running. We need to go and open these up, so i have the gas ballast on the side open. So that way it's pulling most of the air out, so we're gon na. Let that run for a little bit.

I'm gon na go take a lunch. I got a micro engaged tuck back in the back. I ended up adding a liquid line pressure port now so coming out of the dryer. We got a spoiling catch off.

We went with the oversized dryer a 16 cubic inch that way uh whatever plug that thing up um. Hopefully this will help to get rid of it. It wasn't in the oil, so that's interesting, um, but yeah, so we're gon na let this run. While i take a lunch and we'll come back in a bit all right, so we're still assembling the unit, but i'm gon na go ahead and start charging it.

So i've got it hooked up to the high side, we're looking for 6.2 pounds, i'm going to control it from there and we're just following this guy right here. We're just letting it add in 6.2. Pounds is what we're looking for so we're gon na. Let it keep charging and then once it gets closer, we may have to move it over to the suction side, depending on you know the outdoor ambient.

How much pressure is actually in that tank, so we're almost there. It almost is taking the full charge um, even though i did a pressure test and an evacuation. We're still going to do an electronic leak check. I've got it on the turbo mode using the dr82 and we're just going over all the joints, making sure that absolutely nothing is leaking, not picking anything up.

I've already gone over everything, so yeah we're looking really good, not picking anything up. So uh yeah we're gon na get ready to turn this guy on and i think the last remaining refrigerant will have to go in through the low side because it's just basically stalled out all right. Um we're changing this contactor right now, and you know this is one of those weird things where it's a carrier: oem contactor that has screws in the top and lugs in the bottom. So that's not a normal contactor that you go and buy from the supply house, but i've shown this before there's a trick.

If you buy a contactor with lugs, the lugs actually come out below the lug. When you pull this top screw out, there's a screw when you pull the screw out, you can take the lug out and it receive the normal screw from there. Okay, so we can still have lugs on the bottom and screws on the top. Get it all right.

Let's see what happens, we got the contactor replaced. Everything seems fine, one, two three, please don't blow up. Okay, and here we go, we are on and running and uh. Let's give it some time, let the pressures build up indoor blower motor turn on we'll, give it some time and hope that that suction pressure builds up for sure, because it's low at the moment, all right, we are on and running my suction pressure.

The saturation temperature is a little bit on the low side, 35 degrees, but number one. These units run with horrible airflow number two look at the target. It may be in the wrong place. So let's go over here and have a look at our target pressure.

We also need to add just a little bit more refrigerant. We need to get it to 6.2 pounds we'll do that real quick 6.1 just adding a little more 410 there. We go overshot it by a hair, but it should be fine, so uh we can take off the pressure probe and we're going to look at this air probe. So my air probe is a little bit in the high side.

So, let's put it more down in the return airstream instead of right there. So sometimes this can be a problem. So let's do that right there and then let's see what my targets look like now go ahead and put that on and then we'll come on over. Here and see how my system's operating everything's, looking good we're rejecting heat targets lining up a little bit better, we're still a hair on the low side as far as our suction temperature, but we're going to give it some more time.

It's looking pretty darn good saturation temperature on that side is a little bit low, but now that i move that air probe return, air temp is actually really low. We don't have a load at all, so it's only 70 degrees in there right now and we haven't jumped out. So that's going to be the reason why our suction temperature is so low other than that i mean airflow's decent for a three ton: temp splits, a hair on the low side, i'd like to see a little bit of a better temp split, but i'm telling you They got ductwork issues on this guy um super heat's, about where it should be sub coins where i'd expect it to be. I mean this is about all this unit.

Can do it's much better than it was. I don't know what restricted that liquid dryer, but we'll definitely cut it open and have a look at it. I can't even blow through it, so this guy's about as good as it's gon na, be just remember that you know when you don't have a load. 70 degrees, i mean yeah, that's why you're going to have such a low saturation temperature, i mean allowable range would be 30 to 43 right now.

So all right, i'm happy with this. We got a new contactor, the unit's, not short, cycling anymore. All is well all right. It's a running on its own fruition um.

I made sure, because i didn't want to find out that the ems or the internet control thermostats were not working right, so i had already pulled off the jumpers. It's been sitting idle for 15 minutes and then it just turned on so we know that the energy management thermostat is working. The unit is back up and running and again, like i said, we're good to go all right. I just cut this dryer open this little milwaukee cutoff tool is pretty cool all right, so let's open this guy, but still really hot, because i just cut the sides of it.

Okay and then, let's see what this side looks like. Oh wow, look at how plugged up that is holy majoli, what the heck plugged that up holy moly, that is pure mud, my goodness gracious! What is going on in that system, i mean, i'm surprised, we didn't see it in the oil, the compressor oil. That thing is plugged solid, look at the core too. The core has been taking a beating, also yeah, i'm glad we changed that guy out, we've got new oil in that compressor.

Now so, who knows what caused this to plug up, though, all right look at the contact points. Look at how pitted those are, how burnt they are inside there and look at these so big picture stuff. This guy was short cycling on off on off consistently for a while causing damage to the contactor. Now it probably would have worked, but this contactor has a shortened life now because of that short cycling constantly and eventually it would have burnt up all right.

I don't know what caused that dryer to plug up that's interesting, because that was just mud. Like i mean it was just dirt like. Where did that come from you know, that's what worried me and you know i when i when i was walking up. I don't know if i expressed it enough, but when i was walking up and when i diagnosed a low pressure switch and then found uh, the the dryer was plugged up i'm sitting here.

Thinking i've never worked on this, like you know, i'm sure we put service gauges on it to check pressures, you know, but we've. Never. I don't think we've ever changed that dryer. I think that was oem because it had like paint on it.

It was weird, so i don't know, i don't understand what caused that dryer to plug up now mind you. That screen is on the outlet of the dryer, so you know it made its way through the core and then the dryer did its job. That's what it's there to do is to protect the compressor um. You know in hindsight i didn't have one, but i probably should put a a delay on that guy.

So that way you know it doesn't start up right away when it goes off on low pressure. You know we should probably put a time delay relay there. Basically, so that way, it has. You know a five minute before it restarts that way same thing with high pressure too.

So maybe the next time, i'm out there i'll throw a time delay on there um. This is kind of like a budget line unit. The the older units had the compressor lockouts on them. This one didn't have the compressor lockout, so it just sits there and restarts constantly, and you see the contactor too, so you can't just ignore what's going on, but as far as me, suspecting the compressor oil.

I it wasn't so much that i thought the oil was. The problem, i thought that the oil was damaged because what would cause a dryer to plug up on a system. That's never been worked on. You know, and i'm sitting here thinking well, maybe there's damage in the compressor.

You know i figured for sure that compressor oil was going to be black coming out, but nope nope. It was nice and clear, no problems there so went ahead and put back in now. I did want to address that. There's a labeled oil charge on that compressor.

I just made sure i put back in what i took out because i'm sure if i stood there for a little bit longer, i could probably get more oil out of it and there's always a possibility that there's oil floating around in the system a little bit Too so i made sure i put back in what was in the compressor. It's one thing: if i saw that there was a big oil stain or something like that, you know and then it had leaked out, but i didn't see any signs of any oil leaks or anything now to address the refrigerant issues. That's another thing too. You know where did that refrigerant go, i'm thinking that those cormax fittings were leaking and they had been leaking for a very long time.

I heard like a little bit of a leak when i took one of the caps off i could hear you know it kind of like popping at me, so i'm thinking that maybe it was just slowly leaking and uh. You know that added to everything, but you know who knows, but i did my pressure test. I did everything i couldn't find any leaks, so you know we put it back together and started it up now. It was running a little bit low on the saturation temperature suction pressure.

I really think that had to do with the load, and i know that measure quick showed the airflow was good, but that's an estimated airflow um. I'm confident this unit has restrictions in the ductwork. I swear every unit that i work on has restricted ductwork, it's just how they are so i'm confident that uh, you know the the saturation temperature was a little bit low because i think our airflow is a little bit low and um. Also, we had no load right.

It was 70 degrees in the dining room right. It was only like, maybe like 86, maybe 90 today. So it's it's just warming up, it's not getting to the hundreds yet um, but i think uh tomorrow is supposed to be even hotter out there so but they'll be happy now that they have a front entry ac, because that's what that was controlling. So it's all about.

I like to take my time like to go through everything. You know try to figure out what's going on and what caused the problems to happen right. So the contactor was a symptom. Why did the contactor? Why was the contactor burnt? Well, you know because it was short, cycling, okay and the short cycling was another symptom caused by a plugged up, filter dryer.

But what caused the filter dryer to plug up is what concerns me, because i don't know i mean everything was good. So the only thing i could do was i changed the refrigerant to new refrigerant, not that i really thought that there was anything in it, but i still you know changed it to new refrigerant and then there really wasn't anything left out of a six pound charge. If you only pull out a pound, i'm not gon na reuse. That pound, like you, know no we're gon na go in with new refrigerant, but um.

You know and then just make sure that the customer does routine maintenance. I mean i i did everything that i think i could, besides putting a time, delay really on that thing um. I think it is what it is right. I really appreciate you guys making it to the end of the video um.

Oh the other thing. I have a little note right here. I wanted to address the nitrogen fluctuating. Okay, so remember nitrogen does change pressure with temperature.

Okay, it is a gas right, it obeys the gas laws so um. I said that my pressure was going up and down. You also have to remember that i had a trace gas of 410a in there too, and there was still refrigerant boiling out of the oil. So it is going to happen that nitrogen will go up and down depending on the temperature.

But then you add refrigerant into that mix too, as a trace gas, and that is going to make things happen. We were having a nice breeze, and so what i noticed was, as the sun really started, hitting on that condenser. My pressure started going up when i was doing the pressure test and then we'd have a breeze come by and my pressure would go down a little bit. So it happens, and you have to understand that you know you, you need to know.

What's going on and don't just chase a ghost thinking, you have a leak when there's nothing there right so um. I really appreciate you guys making it to the end of the video. If you haven't already check out my website, hvacr hvacrvideos.com, it's great way to support the channel, there's merchandise, shirts, hats, all that good stuff and uh yeah. There's all kinds of information in the show notes of other methods of support for the channel, patreon paypal, youtube channel memberships, but the easiest way to support the channel is literally watch.

The videos literally watch the videos from beginning to end without skipping through anything. That's the simplest way, so thank you so very much and we will catch you on the next one. Okay.