Isolation, diagnosis. So when i say isolation, diagnosis, let's first identify the term. What do i mean by isolation? Diagnosis? Does anybody know find the area right figure out kind of this? Is the area i'm working on, but even more than that, using the system itself to help diagnose the system rather than always hopping in with tools? This is something that people get wrong when they listen to my podcast and listen to my ads. That are way too long that are in the beginning of everyone and all that kind of stuff.

They get the idea that i'm like this huge tools, nerd, i do like tools and i am a tools nerd, but i actually value the senses more in terms of troubleshooting and if i walk up to a piece of equipment where the compressor's not running or where The low voltage fuse is blowing or whatever i'm not going to immediately grab my meter other than to make sure that power's on power's off a few things like that to the overall system, but generally speaking, i'm gon na i'm gon na use my my senses. Let's go back to some obvious things just to prove if you're a real service technician. I should have done this at the beginning. You walk up to a condenser.

Okay, it's running! You can hear it running. What is the very first thing you do when you walk up to that? Condenser put your hand over the top. That's right! Okay, so we guess you're a service technician yeah. So we got a service technician.

What is the very next thing you do after you do that you grab the suction line right and how cold should the suction line be beer can cold see there, you go congratulations, you are all technicians and that's why, like, when i, when i made the beer, Can cold t-shirts? I don't know if you guys have seen those you know. It's got it's a hand grabbing the suction line and it says optimal. Super heat comparison device. You know holding a can of beer.

Some people got mad like when i first did that, because i did this early on when i first started doing the podcast videos and they were like. Are you saying that that's how you troubleshoot a system, that's how you set a charge is by beer. Can gold? No, that is not what i'm saying at all, i'm saying quite the opposite, but i'll be darned. If i still don't do that every time i walk up to a piece of equipment right and the problem is - is that you know, i think, for the guys who top beer can cold.

Some of them went. You know and went to other countries where they drink their beer warm and then they were setting charges all completely wrong. Like you got to think about this stuff, you know so then you just send them the you know the wrapper over the miller cans where the mountains turn cold and then they just wrap that around the suction line. You can just tell from a distance, you don't have to grab it now.

The mountain's blue you're good to go. I am going to read this because it's got fancy words in it. That uh, i don't know. Isolation, diagnosis, making a hypothesis and testing one component or conductor at a time using a process of elimination along the way.

We all did this when we were new to some degree, you walk up to a piece of equipment. It's got a lot of wires hanging out of it. Some people just freeze and don't do anything. But if you're like me, you start randomly testing stuff.

Just like you just grab a meter and you're just like all right. Let's just start touching it to things and see what i get you know, that's how i did it when i first started and it's useless because you're not eliminating things as you go, the most overquoted thomas edison quote that we probably didn't even say it's like most Quotes but you know with the whole um when he tried a thousand ways to make a light bulb and they said you know you failed a thousand times and he said no. I found a thousand things that don't make a light bulb and that is isolation, troubleshooting and that's really what it is. It would be ridiculous if he did it and it was like.

Oh that didn't work. Let's try it again. Oh that didn't work. Let's try it again: oh that didn't work.

Let's try it again, which is, coincidentally, exactly what the new technician does with the fuses wow dang it. I got a bad one, pow dang it. I got a bad one: hey boss, i'm out of fuses right. It's not the way to do that.

We all know that i mean even the guy who's doing it knows it, but he just doesn't know what to do other than that. But that's where you have to have a process of elimination, so process of elimination is another way of saying isolation, diagnosis, but i mean a very specific thing electrically when i'm talking about this, we'll give what we call the the redneck compressor test, and i actually it's Written into our internal process sheets at halos, i don't share all of those because some of them, if they go outside people like to judge too much, but when we test the compressor and a technician finds that it is grounded technician says this compressor is grounded. Do you know the final test? I want them to do, pull the wires off, isolate those wires tape them up, whatever put them to the side. If it's a plug, it's easy, pull the plug off.

Right put it to the side, put the top back on put the power back on, because what should happen if the compressor is grounded and only the compressor is grounded, everything else should run other than the compressor, because now the compressor is out of the circuit right. It was blowing the it was blowing the breaker. Now it's not blowing the breaker. That's the redneck compressor test easy right before i even go to owning things out.

I'm often going to do that. A version of that test. If i do a visual inspection, i go into a condenser, i'm probably telling you guys too much, i'm telling you my secrets, but i go to the condenser i take off the quarter panel. I look around.

I don't see any visual signs of anything. I look down inside the condenser. I don't see any visual signs of anything before i even pull that top off and that breaker's tripped i'm probably going to go ahead and just isolate all the compressor wires, where it's easy to isolate them. Put them to the side.

Turn it back on now, it's working all right. Now, i'm going to go in, take the top off get in and look at my terminals make sure it's not terminals isolating pressure, i'm not going to say compressor, is bad and run. You know, that's the that's! Not the right way of doing that, i'm going to go further, but at that point i've saved myself a few steps. Now you could just as easily do it with an ohm meter and all that, but i learned early on just not to trust.

I think i had a bad ohm meter or something where a lot of times it just wouldn't show me that it was shorted when it actually was. A lot of people ask why that is, if you've ever done this, where you actually test the ground on terminals, and it's not giving you like, it's still not showing a grounded condition. Just remember that inside that compressor, if the thing is grounded it's not like a nice little clean thing, it's not, i think you know sometimes in our minds. We imagine.

Oh, this winding is just it's it's bare and it's just sitting there. It's just touching the edge of the compressor. You know nice and clean, but actually it's this mess of carbon and crap, and just this big messy environment. So it's very possible that this thing sitting there off after it's shorted and it comes to rest.

It's actually not grounded right now, but if it moves a quarter inch, it will ground again or if you apply a high voltage to it, it will ground again. Anybody here use the supco mega meter, the one with the lights on it. Do you know the problem with that tool? I didn't know this when i first got it, do you know the problem with it? It will tell you that a compressor is bad when it is not bad. I know it's amazing.

My system sales were higher than they've ever been. The caveat is, is that it's really designed for open, open, winding motors, it's not designed for motors that are immersed in oil and refrigerant, specifically scroll compressors, the scroll compressors. Do you know where the motor is on a scroll compressor? It's now at the bottom. Have you ever taken like a big train, orange compressor or a bristle, or anything like that, an old resip and then shook it around? What do you hear right and why is that? Because there's a lot there's springs in there sitting in suspension, but there's a lot of space.

It's like phil collins. You know, there's just an empty space. Sorry these things come to my head and if i don't let them out something dies inside of me, so i apologize, it just happens. Sometimes no there's a lot of empty space in there.

Even if there is something that's amiss, it's not necessarily going to conduct to the casing in the same way or even just under normal conditions, because you know what what a winding is coated in. Have you ever paid attention to that? It's like it's like a lacquer right, so you have all these windings they're real close to each other, but it's just got this really thin orange coating on it right. Just a lacquer is that lacquer 100 insulation that no electricity could ever make it through under any circumstance. No, no, it will conduct.

So when you take a megometer and you apply whatever the voltage is 250 volts or whatever through that mega meter and that down scroll motor is sitting just that far away from the edge of the shell, a lot of control compressors, especially when they're cold, that you Mash that button, that thing will say bad literally, that's what it says bad on it. I took that away from all of my technicians. I was one who gave it to him and i was like hey give that back. I appreciate the system sales, but yeah give that back right.

That's the reason why i don't love that particular test now. What i've done instead is, is they make these pretty inexpensively fluke makes the best ones. The 777, i think, is one of them within that range. 700 range they're great, but you can also get these pretty cheap ones on amazon.

They even have some that still have the dial on them, but i got the one with the numbers: just 30 40 bucks. You almost never use them, but instead of saying bad, it just gives you a readout, that's much better, because now, when you hand that to somebody now now you may get the phone call hey. It's saying you know 30 ohms. Is that bad yeah? That's bad! It's saying one mega ohm: is that bad? No, probably not, it may be that it's you know the lacquer is getting a little worn down or maybe contaminated oil, which is most likely, but that's not necessarily bad on a scroll compressor.

In fact, when you read copeland specs, it will say down to 500 kilo. Ohms, which is half of a mega ohm, is still acceptable or that's the acceptable range. So that's high voltage in low voltage. I teach the same thing: isolation, diagnosis, it's blowing a fuse.

It's tripping a breaker on a transformer, the low voltage, the low voltage circuit breaker on the transformer. My first question is: when does it do it instantaneously, or does it do it during a cooling call we had one recently. Actually i didn't have it. It was my service manager having to be sitting in my office, and one of the texts called him and you guys have probably already seen.

Oh we've already seen this many times, but the thing won't come out of time delay. It goes all the way through time. Delay gets to cooling call and then it just goes straight back in time delay again anybody seen that one. What is that? It's it's a voltage drop and it restarts it.

But why is there a voltage drop because there's a short there's, a voltage drop and it's caused by a short and so the thing restarts time delay every time. But where is the short when that happens? It is usually the contactor coil. It is but it's in the y circuit somewhere. How do we know that? Because if it was a short and red, it wouldn't even start going through time delay if it was a short in green, i guess it could be a short and green, but you could you know you'd put the fan the on position.

Blower comes on right in this case. We did that if it was a short and o well, the o is already energized just when it's put in cool mode. So it's not a short there, because it would have blown at that point. So we've already isolated without isolating without pulling anything apart, we've already isolated.

Now, because we have tribal knowledge that teaches us that it's probably the contactor coil, because that's a new thing that all of a sudden started happening like when did that start happening that didn't used to be a thing like i i mean i worked for almost 20 Years and we did not have that problem and all of a sudden, the last three years - contactor coils, just shorted all the place - anybody else experiencing that like what's up with that yep, that's another one pressure switch wires, exactly that's another one that can be, but the Next thing i would do is just go out to the condenser again, knowing what we know now: i'd probably just open up the contactor coil, but go to the condenser pull the y wire off at the condenser. This is isolation, diagnosis, because if i pull the wire off at the condenser and then it does go through time delay and it does lock in what do i know, i know that it ain't the wire - it's not the wire in the air handler. It's not. The connections in the air handler - it's not the thermostat, it's something in that condenser, which leads me to pressure, switch wires contactor.

I would probably before i even do that. There's a look down at the pressure switch wires. Just make sure that they're not shorted, but that's isolation, diagnosis, observational, isolational! I don't think that's a real word. Did you guys ever see? I didn't put that in here, but i should have put that in here.

Did you ever see that picture that i pulled from the electrician's handbook in the 1920s? Never anybody ever see that i mean you wanted to talk about just a generation of studs back then i mean it literally tells you that most men can handle a voltage up to 250 volts without too much discomfort. It's not bad enough that it's telling you to nearly electrocute yourself, but then it also questions your manhood. If you're not willing to do it, you know it's like most men, you know what is that this is ridiculous, and then it tells you when you're testing a bell circuit. If you guys have read this, this is not a joke.

I've got two copies of these because i needed to have a backup in case somebody got rid of the first one. It says that when you're testing a bell circuit with a very low voltage, you can place it on the tongue in order to test the sensation. To see if it's activated uh and if that doesn't work, it tells you to take your shoes off and stand in a puddle of water. I am not joking.

You it's crazy! That was before they had. You know it was before your average electrician had an electrical meter. You know so like well, what are we gon na? Do? I guess you know, take off them socks, just don't confuse the two. Don't take off your socks and put it on your tongue when it's 250 volts.

That's what i'm wondering i'm wondering about the poor schmuck who died from that. He combined all the techniques into one. That is isolation. Diagnosis.

Did he die? Yes? No! Yes, okay! Move on to the next one: it's really really simple, and once you get this in your mind, then you can create your own versions of isolation, diagnosis. Once you know these tools, most of it, you could do even if you didn't have a meter now. Obviously, i'm not saying that you do that because, especially if you're working on high voltage, you need to make sure it's off in the first place. So you need to have a meter right, but a lot of the tests that you do.

You confirm that you confirm your hypothesis before you move on anyway, especially when you have cases like. Has anybody ever dealt with issues with ghost voltage before like where you're measuring voltage, but then like it's not actually doing anything, and in most cases, when we see ghost voltage, it's not usually the case where you're getting induction inductive gains. It's actually just a really high voltage drop easiest way to imagine this is imagine that you've got an issue with water pressure at your house and you shut off every faucet and every toilet and everything in the entire house. And then you go to the furthest faucet and you test the water pressure there, not the flow just the pressure.

Is it going to be good or bad, probably going to be okay because nothing's moving nothing's flowing, but then the second that you turn the faucet on and then you measure the pressure? That's when you see the big dive and that's what we do in a lot of cases, we're like i got voltage but then, as soon as you try to use that voltage, it goes away right because you have volt. You have pressure there because voltage is pressure right, but as soon as you've got flow now the pressure disappears most cases when we're. You know when we're running into that. The easiest way to do it is just to try.

You know a component use an actual component as your test, so i'm measuring 24 volts here. Let's see if that 24 volts will energize this contactor that i've got at this point now, let's try it at this point now: let's try it at that point right now. The problem is, you could also have a common could be the issue of what you're losing and that's actually where it gets tricky, but go ahead and take one of your extra spare wires wire it up as a common see, if that you know so, you'd be Creative with it there's a lot of problems, you could solve weird problems by just thinking: isolation, diagnosis, rather than always like. Well, my meter's telling me you know: that's that's where a lot of guys go wrong.

Another place where a lot of people go wrong in terms of not using isolation. Diagnosis is they do a form of um like i call it process, diagnosis, process. Diagnosis looks something like this. Jim bergman uses.

This example he's like when he first started working with his dad and they would show up to a furnace that wasn't working or it wasn't. I don't even know if it was a dad, but when he first showed up to a furnace that wasn't working, what he would do is just rewire the whole furnace and the reason he would do. That is because he knew how to do that. Now, that's a pretty good thing to know how to do it's very handy, but it's that whole idea of.

If you know the only thing you have is a hammer. Everything looks like a nail. That's a version of that. So it's like when you teach a guy.

You teach a good old buddy how to uh wring out wires. You know what i'm talking about ring out wires. You go, take all the wires hold them together in one end to go to the other end and you own them out just see which one's open. Well, that poor fella is going to do that every time he has any electrical problem whatsoever be like well, the wires are all good.

What do you mean by good? Exactly i mean they all ring out. Well, that doesn't mean they're, not shorted, well yeah, but they all rang out so they're good. Heaven forbid, you teach the guy how to pull a new stat wire, because then every time he's gon na pull a new stat wire anytime there's any problem with the system. As well and i'm not joking - i had a guy who would do this to me and i'd be like larry? Don't do that like we don't know that it's the wire between the condenser and the air and he's like oh boss, i was convinced it was.

I pulled a new one, you know it's like. No, don't do that and that's the problem, that's what that's what we that's, what a lot of people do and all they can think is in terms of a process. An example is, a technician, goes out, they've been doing maintenances the whole time. And what do you do in maintenance? You clean drains wash condensers change filters right, so they go out.

Compressor is not running they clean. The drain. Fuse is blown they wash the condenser. Is it bad to clean drains and wash condensers? No, that's great! Once you get the unit working, you know, once you have confirmed.

The first thing is one more valuable than the other. Well, not necessarily, but they've got to be in the right order. So getting really good at your troubleshooting tools, so the stuff we're talking about here do that first then find the cause of failure, then optimize system performance, and that is what i call wide narrow wide diagnosis thanks for watching our video. If you enjoyed it and got something out of it, if you wouldn't mind hitting the thumbs up button to like the video subscribe to the channel and click, the notifications bell to be notified when new videos come out, hvac school is far more than a youtube channel.

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