This video is brought to you by sportlin quality, integrity and tradition. All right. We have a complaint that the kitchen is too warm it's kind of funny, because i just did a video on this well, i just released a video, but it was actually filmed like eight months ago, but anyways so they're complaining that the kitchen ac is too warm. This is one that we fixed a leak uh, it was leaking.

There was a bunch of refrigerant leaks on the evaporator, so the unit is running whether or not it's running properly. We don't know so we need to kind of dive into this guy. The first thing that we will do is open this up and have a look at the control package and see what uh what's calling and what's not all right get into here. Um.

It's not really gon na be visible to you guys but yeah, but it's a status and it's basically saying cool two on cool one on so we're good there, both contactors are pulled in one thing i do notice, though, is both of the suction lines. It's gon na be hard for you guys to see, but they both look frosty well, this kind of makes sense. Uh compressors are running, both suction lines are frosty, and i open this up and the indoor blower motor is not running um motor's cold, it's not hot, and we have a vfd sure we got ta, look and see if that vfd is getting power or what's going On with that very carefully maneuvered the vfd - and i don't see any lights, saying power or fault now these vfds they don't come with a display. I'm pretty sure i have one in my van, so i'm going to run down there and see if i can grab it and plug it in so i ended up having a display in my van.

I keep these because you have to purchase them separate. So, let's see i don't know if this will work or not, if anything blows up on me, it doesn't want to go in there. Let's put that in first there you go and then let's try to snap this guy in nothing, no display. No anything! It's just blank, i wonder if the vfd even has power um i mean, i know it has power it's going to be powered.

This is your fan, speed right here for the speed, but it's probably grabbing power off of these wires right here. These blue and these blacks and they're probably running over and then they're grabbing another power source from somewhere else. Let's uh, let's open this guy up, maybe the cover comes off and we can test voltage in there. Maybe there's fuses all right, there's a screw in the top, be very careful.

This is high voltage. Obviously, all your protective stuff and everything just to be safe, um covers off. You can now see the electrical connections, so what we're gon na do is go ahead and put this guy right here and then we're gon na test power coming in so 201 volts line, one to two. I can hear it clicking like there's a bad relay in it too, two to three 199.

one to three 199.. So we have three phase power coming into this vfd and we have no power exiting the vfd, nothing it's dead, so we're not getting any power out of the vfd. For some reason it's not turning on and we don't have a power or a fault light either, which indicates to me that we're going to have a bad drive. These things are notorious for.

Failing, i don't see anything else going on with it. We're gon na go ahead and turn off the power, be careful. Let it sit for a few minutes before we start messing with the drive we're gon na look around um, i know in the smaller ones they have external fuses. I want to make sure there's nothing on this one because i don't see any fuses at all, so i'm gon na just investigate the drive to make sure there's nothing to reset it, but i don't think we're gon na be able to it's probably going to end Up being a bad drive, i'm not seeing anything, no reason why this drive shouldn't have power, um yeah and, like i said i could hear the drive clicking and it's just not you know, something's just not happening so we have an internal drive fault, somehow something's dead In this guy uh, what we're gon na do is uh.

We are actually gon na go ahead and install a contactor for the indoor blower motor. That's pretty much become common practice. Getting these drives right now is a disaster. On top of that, it's not very cost.

Effective, so we're gon na go get all the materials we need to install a contactor and completely bypass the drive. So i turned the unit back on and i'm confident the drives messed up, but i'm just trying to make some sense of it. So i'm looking at the control wires right here and we have no voltage. So i have a 24 volt input right here and i have no no power whatsoever as far as low voltage coming into the drive, but still i have no display.

I should have a display because it should be powered from the line voltage coming in and we don't have a display. I was just kind of playing around trying to figure it out. I have a call for the fan at the control control board and i also have a call at this wire right here with it, which is the indoor fan contactor 24 volt lead. So, actually that's what we're gon na use to bypass the drive right there um, but i have 24 volts there.

So we're calling for the indoor fan but for some reason we're not getting a signal to the drive to turn the fan on, but still i think that the display is controlled from the high voltage coming in, but i'm still just kind of playing around with it. Before i go full into it and bypassing it yeah this guy's dead, i traced it back. We've got 24 volts. I don't know why it's getting lost going to the vfd, but we're going to go ahead and bypass it um.

What i find funny, though, is the vfd comes right out right, and these are your power wires notice. These are female plugs and these are the wires go into the motor and notice they're male plugs, so they literally make it. So that way, you can bypass the vfd very easily. What does that tell you interesting right, but we don't want to just bypass it, we're going to go and install a contactor and permanently bypass it.

So that's what we need to figure out right now, all right! We know that the drive the motor works, because it's running, i hardwired it - i don't have the contactor wired in yet, but i hardwired the vfd in too just to make sure to the 24 volt circuit to make sure that wasn't what's powered the display and it's Not it's not running so i'm 99 sure it's powered by the high voltage, but i just wanted to make sure i applied 24 volts and it still doesn't open the display or anything like that. So this drive is definitely bad. So we're going to proceed with installing the proper contactor to make this a permanent replacement. All right.

If i did things right, we have a contactor wired in uh. There was a indoor fan wire right here. It was actually the other side of this. This is going to the uh two speed relay board right here, so we grabbed the power going into that we'll tape that off here in a minute and we're gon na fire.

This up hope nothing blows up on us. Indoor blowers should turn on it's going in the right direction. That's good yeah! So we're going to put it back together, finish zip, tying things up and then probe up on it make sure everything else is working properly. All right we got all of our probes set up for measure quick.

I get a bunch of people asking that's, not a laptop, that's my tablet. I just have a keyboard on it with measure quick. You can use it in the landscape mode um, but yeah. It's convertible: it comes right off, so we're all probed up with all the job link probes, we're ready to go contactors labeled, we're just going to kind of put this panel up start it up and just do a quick check out on the probes, make sure everything's.

Looking good all right, this is our initial startup. We haven't really let it stabilize out yet or anything. So it looks like we're a little high on the head pressure. Scroll on through superior sub cooling are yeah, okay, nothing too crazy.

Again, this just turned on so temperature splits, not too too bad. Let's go to the second stage circuit two about the same. Look at that superheat something's going on there. Maybe we got it in the wrong place, we'll have to check okay, not too too crazy.

We got to check on that probe placement, though, for let's go to toolbox and then liquid line temp 100 degrees discharge line temp 143, the other liquid line 106. suction lines are all accurate. I mean everything's, looking pretty good, we'll give it a minute. So what's the deal, why is our on the first stage, our superheat's two degrees? Second stage? Oh, it's fine! If, for some reason it said 30 degrees a minute ago, but so it's really important that we understand what's happening with our probes.

In this situation we were showing higher than normal head pressure, but i went and moved the outdoor air probe and it's better. I moved it more into the sunlight, so you have to move the probe as you're working on the system depending on where the sunlight and what side of the condenser is being used. So we moved it more out into the sunlight, and now it doesn't look like we're running high head pressure. Superheat looks good, it's a little low, but it's still, you know coming down so but yeah.

There was a high number on the super heat in the on the second stage when i first started it up, but it's looking good now, all right so yeah probe placement is very important. Um condenser is a little dirty, but i think we're going to be okay. For now i don't see the need to wash it today. It's not that bad getting all of our air probes out these vfds.

They do fail and right now we can't get them because of the shortages everybody's backordered on their vfds. But even then it's not under warranty anymore customer they're going to be just happy with the contactor. I know they lose the two-speed capabilities, but it's just not cost effective for them. They usually don't want to go with the vfds just like when the economizers fail.

Half the time on these guys, they don't want to fix them either so, but anyways all right. Well, that's it not too bad all right. Today we are playing what killed the vfd so um i was thinking. Maybe it was a fan motor.

The cooling fan right. I'm gon na go through everything and i'm gon na show you what i think happened here, but i think the cooling fan was part of it, but there's more to it. Okay, so the cooling fan still has resistance, and i imagine i don't know what the voltage is on that fan. I imagine if i investigate it, i can probably plug the fan into something, but a couple things i'm noticing number one.

So we still have resistance across the motor, but this plug this plug is corroded. Okay, look at the inside turn the light on you guys can see that the the terminals are corroded they're corroded inside too, where it plugged into the board was also corroded. Okay, but i'm going through the unit and number one this uh drive, this variable frequency drive was mounted inside the mixed air cabinet right. So after the evaporator coil before the heat exchanger and in that area right there, it is susceptible to very high heat temperatures and very low cooling temperatures also really high humidity, okay, and that is reflected by looking at everything i mean we clearly have mold growth right.

You got mold growth on there, you've got dirt and all kinds of stuff built up inside here. That can't be good. There's literally grease on this cooling fan. Okay, so that's not good, but then we come down here to what looks to be the main pcb circuit board for the drive, and we have a burn mark right down in here so right here we have a terminal that is burnt right there, okay um! So that's not good, but also looking at the board.

It's got a lot of moisture issues and just very, very crappy, greasy whatever, and that terminal that's burnt is coming right. I believe i figured it out it's right here on this guy right here so r168. I believe is what's actually burner so more than likely. That is what caused the drive not to work anymore, but i have a very strong feeling it had to do with the high humidity conditions um.

I also noticed that there's thermal paste on the back of this um right here and the thermal paste isn't like it. There wasn't very much either it didn't seem like they did a great job there um that went right here on the back of the um. What do you want to call that a heatsink? Maybe i think, um but yeah, there's just corrosion everywhere in here i mean look at that's the cooling fan terminal right there. So, even though we have resistance across the the motor, i have a feeling it wasn't making a good connection and that could have been leading to an overheat situation.

Just goes to show you that these drives really shouldn't be located in the uh cabinets that they are. I mean look inside here too, just worn out so anyways. I was just kind of curious, this kind of solved, my curiosity as to what was going on with that uh that drive all right now these air conditioners come with two speed indoor blower motors. They usually use in this situation.

They use a vfd. A variable frequency drive that variable frequency drive is able to modulate uh the frequency at which the motor runs right and it's able to speed it up and slow it down, depending on certain conditions. Now sometimes you can have a completely variable drive where it can slow it down and speed it up based on certain parameters. This one is not set up that way.

This one is set up to run at two speeds: okay, and what they're doing is they're trying to save energy? If you think about it, you have a package unit. Let's just say this is a 10-ton unit. Okay, if you have a 10-ton package unit, typically okay, especially here in southern california, we typically base it off of about uh 400 cfm's per ton. Okay.

So in that situation, if you have both compressors running you're going to be moving a lot of air right, because you need that 400 cfm's per ton right and you've got 10 tons, so you need 4 000 cfms moving across this unit. Okay, but what happens if you shut off one of those compressors? Well, normally you're still going to have 4 000 cfms of air moving across it, and your first stage running by itself. The single compressor five tons is now going to have 4 000 cfms of air moving across the evaporator, and it's not going to be as effective. It's not going to be as efficient, basically, okay, so what they do is they put a variable frequency drive that runs at two distinct speeds and they figured out the right amount of speeds to move the right amount of airflow.

So whenever you call for first stage, you run at slower speed, but when you call for first and second stage it speeds up and runs at high speed, so that way, you're not wasting energy right and you're, not losing efficiency, but here's the problem. We have all these energy efficiency mandates and regulations and different things like that, and i'm not denying the science. I totally understand that you can be more efficient if you reduce the air flow, slow it down when you're running. Just one compressor speed up when you're doing two, the variable frequency drives are not installed in a good location.

In my opinion, they should be installed in an electrical cabinet downstairs in the condition space where they don't have varying uh temperatures. They shouldn't be installed in the indoor blower section like they are in this unit or in other units. They shouldn't be installed in the package unit, uh compressor, section: okay, because they're just it, they just go through extreme conditions. They also need to have better power, conditioning, in my opinion, okay.

So in this situation we decided in talking with the customer, to go ahead and install a contactor, eliminate the two speed option, because even if i could get the drive, those things are stupid expensive and there is no return on investment. When you look at the big picture, even with the energy savings, it just doesn't make sense: okay, um, so we went ahead and put a contactor in there. We run it at full speed all the time. So, yes, it is gon na be a little less efficient.

With just the first stage running, but this is a much cheaper option and the air conditioner is going to work fine, they do lose a little bit of efficiency when they're just running with one compressor. But honestly, this is a kitchen. It's going to run with two compressors majority of the time because they have a high heat load in that kitchen. So it's really not going to be a big deal, and it's really just about you know money really when you put it down to it, the customers.

Don't want to spend any more money than they have to spend and they don't you know it doesn't make sense to them to to to keep up on all these energy efficiency things when it's not saving them any money. It's it's costing them more money to have to replace this drive than it's going to save them, so it just doesn't make sense financially for them. So, of course, i want to put in a new drive in this unit, but when i bring it up to the customer, they don't want to. You know they just just do what you got to do to get it working, make it function and be done with it.

Okay, so in this situation now we have a compressor, contactor um. This is happening more and more uh. You know it's just unfortunate. We've had a lot of these drives fail.

I've actually talked to the manufacturer, abb um. I think it's alan bradley company or something like that, but i've actually talked to like their sales representatives and stuff, and it's very interesting, i'm not going to publicly say, but it's very interesting what they have to say about the location of these drives and about the Type of drives that was purchased and the quality of them and different things is very interesting, very, very interesting, but that's all i'm going to say about that. We're not going to go too much deeper on that, but yeah it is what it is. I did what i had to do to get the customer operational um.

I do want to address the the probe placement when i was using my tablet and everything. I want to talk a little bit about pro placement when you're dealing with multi-stage equipment that has multiple compressors. You need to remember that sometimes you might have to move your air probes, even if you're dealing with a big package unit on the indoor section too, if you're checking second stage well, that might be the top half of the evaporator. So you may need to move it because, depending on the situation, they may be pulling a little bit more outside air through the top half of the evaporator than through the bottom half like.

So you need to understand how your equipment works and move your probes appropriately. Okay with the outdoor air probe on this one, it was, it was shown that i had really high head pressure, but what happened was majority of the condenser was in the sunlight and i had the probe in the shade. So once i move the probe over to where the majority of the condenser was in the sunlight boom, my my my targets and everything were good according to the the software. So you have to understand - and this this this software is amazing.

I love digital tools. I love digital probes, but there's it's not just as simple: it's not dumbing down the industry there's more to it. We have to know how to interpret the data and make sure that it's accurate and if it's not, we have to know how to dive deeper. So when my superheat was really high, i immediately said: hey, let's look and see if we have the probes in the right place, so i went to the tool manager and it was just taking a minute to read or something because then the super heat was fine.

Okay, so you know we have to use our brains, these smart tools, they're not going to do our jobs for us, and we have to understand and be able to to tell when the probes are giving us bad information too. Okay, i'm not just blindly trusting some software and some digital probes, i'm using my brain and my experience and looking at everything and saying okay, this seems good everything looks good, i'm good with it. Okay, i really appreciate you guys making it to the end as usual. It's so humbling, if you guys haven't already please check out my website hvacrvideos.com, we have merchandise available on there.

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I think in every shirt and every hat i think i make five bucks off of them, so we're not trying to to to get rich off of it or anything. Like that, it really just kind of covers all the the labor and stuff that we put in my wife handles all the shipping. We have all the merchandise sitting here behind, where you guys can't see and uh. You know when we get the orders she packages everything and makes sure it gets shipped out appropriately.

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We will catch you on the next one: okay.