Mastering Your Meter Advanced Functionality with Louise Kellar (UEi Test Instruments)

HVAC School - For Techs, By Techs

Host Brian Orr welcomes Louise Kellar from UEi Test Instruments to discuss advanced functionalities of digital clamp meters and multimeters.

Key takeaways

• The UEi High Accuracy Clamp Meter (HAC) is designed to provide precise readings at very low currents common in modern condenser fan motors.
• Measuring power factor is essential when working with Electronically Commutated Motors (ECMs) to avoid incorrect wattage assumptions.
• Microamp ($\mu$A) measurements are a critical tool for performing flame rectification testing on gas furnaces.
• The Low Z setting helps technicians eliminate 'ghost voltage' by creating impedance that bleeds off transient readings.
• Diode testing functionality can be used to diagnose control boards in mini-splt systems.

Main topics

• Advanced Clamp Meter Functionality
• Power Factor and Wattage Calculation
• Microamp Measurements for Flame Rectification

Notable quotes

It's not about memorizing what's on the meter. It's about knowing what the measurements mean.

Conclusion

The episode serves as a technical deep dive for technicians looking to

Transcript preview

Speaker 3 (0:00) Music Speaker 2 (0:04) This episode of the HVAC School Podcast is brought to you by our trusted sponsors. Refrigeration Technologies at RefrigTech.com and specifically the new Viper Wet Rag Heat Shield. The revolutionary flame-resistant welding pad designed to be used either wet or dry. Find a Viper Wet Rag Heat Shield at a distributor near you or go to TrueTechTools.com and use offer code GETSCHOOLED for a great discount at checkout. Carrier and Carrier.com. NAVAC at NAVACglobal.com. Filtrete Air Filters at Filtrete.com. Filtrete has been going above and beyond other filter manufacturers because it rates its filters' effectiveness in capturing even microscopic particles. You'll see a MERV rating and an NPR rating on the packaging. NPR stands for Microparticle Performance Rating. And it rates how well a filter can capture tiny particles like smoke, bacteria, and more. Filtrete filters are designed with pleated media that maintains similar airflow levels across MERV ratings 8, 11, and 13. According to data published by the California Energy Commission, Filtrete's 1900 MPR MERV 13 filters have the highest airflow rating among available residential 1-inch MERV 13 filters. Learn more about Filtrete's filters and standards at hvacrschool.com slash Filtrete. Speaker 3 (1:34) In a world where nobody checked airflow first, one man still Speaker 2 (1:39) does. Your host, Brian Orr. Heidi, Hody, Hirdi. This is the HVAC School Podcast. I'm Brian. This is the podcast that helps you remember some things you might have forgotten along the way, as well as helps you remember some things you forgot to know in the first place. In this episode, I'm talking with Louise Keller, my good friend from UEI Test Instruments. Louise spends a lot of time training contractors and wholesalers and helping people understand not just what buttons to push, but what the multimeter is actually telling you. In this case, we're talking about clamp meters a lot. So we talk about some of the familiar things, but then also some of the less familiar things. There may be some things you learn here. Maybe not, but either way, it's a good conversation, especially a good one to share with new techs out there who maybe are just getting used to using their clamp meter, and they may not know what some of those features do, some of the things to watch out for. Like always, it's not about memorizing what's on the meter. It's about knowing what the measurements mean and what can throw you off when you're trying to use it. And maybe what you should do next. So let's get into it. Talking with Louise Keller about advanced functionality of your meter. Speaker 2 (2:52) Thanks for joining me on the HVAC School Podcast, Louise. Speaker 1 (2:56) Oh, I am so happy to be here, Brian. I wasn't quite sure if I'd get invited back after the hot water heater incident. So hopefully you've forgiven me for that and we can move on. I Speaker 2 (3:07) haven't. But since you were so right and I was so wrong, I have to eat my crow. It's not easy, but I've got to take my lumps, try to forgive and definitely not forget. It's just one of those things. Speaker 1 (3:18) All right. Duly noted, sir. Speaker 2 (3:21) Always good to see you. Before we dive in, the audience knows you pretty well, but anything you've been up to lately that's been exciting or new or fun? Speaker 1 (3:29) It has been a very big year of travel going on. Recently, just last week, I was actually out in Garden Grove, California. I was at the National Carbon Monoxide Awareness Association. They have an annual summit that we got to participate in. And we have some exciting things that are going to be coming through our partnership with that. I know a lot of times when we've talked, we've chatted a lot about the dangers of carbon monoxide, and they've just been a wonderful resource. And every time I think I know a fair amount, I realize that there is still so much more for me to learn. That was really exciting. That was last week. It was interesting. They had some speakers from the UK. and seeing just how vastly different the European and the UK market are from our own market and what they're looking at in some of their research has been really fascinating to me at lower levels. So that was really exciting. Next week, I'll be at the NCI Summit, which is always a good time. Again, another great event that we have going on that just my mind's blown by the amount of knowledge and... the people that you get to meet in this industry. Speaker 2 (4:44) Yeah. NCI is a really fun group. We're excited to go there. Leilani and I are going up there. Ty and Perla are going up. So we're going to have a blast representing Grit Foundation. And Ty's going to be speaking. I don't have any speaking, so that's fun. I get to just attend. So it's going to be enjoyable. Speaker 1 (4:59) It's a little different when you get to take a little bit of a backseat. It's a whole different perspective, but you'll actually be able to have some time to go enjoy some of the speakers instead of having to be responsible. make sure that everybody's getting on the stage and that you're on the stage at the right time. I feel like there's going to be a lot of learning, no matter how much you think, you know, there's always something new to learn. Speaker 2 (5:21) Absolutely. For anybody who doesn't know what we're talking about, if you want to find out more about the NCI Summit, go to gotosummit.com. That's their website. It'll be too late this year when you hear this, but you can always attend next year and we look forward to seeing you there. I want to talk about CO again sometime because boy, do I have a story around that. And I have bought more UEI CO monitors than probably almost anyone in the country when they first came out because of a little incident that happened to my own business, which we'll talk about another time. But another thing I've bought a lot of recently is a lot of UEI meters. UEI has a really great full line of meters, and they really are the ones that we use every day here at Kalos now. So I thought, hey, this would be a great topic. Let's talk about mastering your meter, advanced functionality. Everybody knows how to twist the knob and measure volts and amps and ohms usually. But let's talk through some of that. So I'm going to tee that up. Speaker 1 (6:08) Yeah. Speaker 2 (6:09) Why do experienced techs still misuse their meters or what do they most often misunderstand? We'll just start there. Speaker 1 (6:15) That is a very large topic. Speaker 2 (6:18) It is. I didn't dial it down much for you, did I? I just gave you the whole thing right there off the top. Yeah. Speaker 1 (6:22) No, no, you left me still about 90 % of the dial on there. What's interesting is recently I was watching a video that Ty Branaman did, and he pulled out meters. And it was like meters over the different generations and different decades, starting with some of the basic analog meters and then moving all the way up to the more advanced meters. And I think, though, sometimes you learn whatever part you joined into the trade. you learned on what was the meter of that time. And even in the last couple of years, meters have just escalated in the amount of functionality that they have. But when you go back to some of the trade schools, they're teaching you your volts, your amps, your ohms. They're not necessarily going into what is power factor. What are we looking at? on the different equipment, what's the wattage? And so I think dialing it in and understanding that the meter can do so much more than what they used to be able to be capable of. And while primarily you may only be looking at your amps, volts, and ohms. your meter can really unlock a lot more for you. So I believe one of the meters that you guys bought was our new HAC, that high accuracy clamp meter. So one of the things that we worked really hard on on that meter is actually when you're doing your amp draw, because the new equipment out there doesn't have as high of an amp draw. And when you're trying to do some of your diagnostics, if you're not dialed down low enough, you're not going to be able to get an accurate read and really see what that amperage is. So that's something that we've introduced is just lowering down that range in the amps because we've talked about it. Rarely are you ever going to, if we're doing residential, see over 200 amps when you're doing your amp clamp. But it's very possible you're going to see under one amp. And so now having that dialed in is a really important functionality for you. Speaker 2 (8:30) Yeah, you bring up a really good point. This is one of the first, I mean, you jumped right in. We both did. This is one of the first things I wanted to talk about was this high accuracy clamp meter, this HAC. It is the one that I just up and bought 20 of as soon as it was released and handed them out to a bunch of technicians because I was so excited about it. And what makes it so exciting is what you already just mentioned, is that by decreasing the designed amperage range, current range, you're able to read much more accurately at lower currents. And that's something that a lot of people don't realize, is that when you set the range of a device, if you tend to go up to the really high ranges, then you tend to lose accuracy down to the lower ranges. So you gain that accuracy. And that's really important when you're trying to measure wattage, especially on condenser fan motors, especially on... blower motors, especially on blower motors. It's really a big deal. And if you're trying to even do things like test if a capacitor is accurate under load, a lot of people have been getting a lot of wrong readings and they think that it's because there's something wrong with the capacitor. But often it's because the meter just isn't reading accurately on, say, the condenser fan side or accurately enough for it to give you that resolution. So this meter is really designed to do that well. Speaker 1 (9:37) Yeah. So I was really excited. That was one of the big things, hence why the name, the HAC, High Accuracy Clamp Meter. But you went into being able to read watts. And traditionally, watts has been factored as amps times volts. So if you could see both of those readings, you could do the math to get there, and you'd be pretty close on that wattage. But now having a meter that allows you and does that calculation, that's one less step A that somebody has to do. But it also takes away a step where you could have an error because I'll be the first one to tell you math is not my strong suit. So if there is a chance for error, I will probably make it in a mathematical equation. So now I don't have to worry about that because the meter is going to be able to calculate that for you. Speaker 2 (10:32) Yeah, it's that power factor side of things. If you don't, a lot of people say volts times amps equals watts. And that is true in a DC fully resistive circuits. In a inductive circuit in alternating current, you get this case where your voltage and amperage can lead or lag each other. And that creates some energy that's moving through the wires, but it's actually not doing real work. In the case of electronically commentated motors nowadays, ECMs. they have really low power factors. That doesn't mean they're actually inefficient. If they were an old school motor, it would mean that. It just means that they have this utilization ratio and it's based on how they operate the motors, the PWM that operates the motor. And so if you don't have power factor and you're measuring on an ECM, you're going to be really inaccurate. In the past, you'd be close. A lot of the decent compressors, decent motors are going to run close to one power factor anyway, but nowadays it becomes more important. Because if you don't have that, you're going to think your motor is drawing a lot more wattage than it actually is. And especially for people who do energy rating or are trying to prove the efficiency of equipment, you could think that a piece of equipment is really inefficient when actually it's just because you're not measuring power factor. So using a meter like the HAC allows you to dial that in and also dial it in accurately. It hits all the key points where before you may have had one that had Bluetooth and could measure wattage, but it wasn't accurate on blowers. because it wasn't accurate down low enough or accurate on connoisseur fan motors, where this brings the accuracy, brings the Bluetooth connectivity so that you can measure with the panel on when you're doing a blower. And it brings that full power meter measurement, that power factor, wattage and amperage simultaneously. Speaker 1 (12:09) Yeah. And I would say one of the other common things is just for people out there, just really understanding power factor. Because it's easy to think that whatever is incoming is just getting fully used and people don't realize that there's a lot of that power that is just not being used. I do a presentation on it and I use a frosty glass of root beer that has a nice foamy head on it. And that's the power that you're losing. Like it's there. It serves a little bit of a purpose, but it's not actually being used for much. Being able to explain that and understand that that's another thing. And again, that's something that a lot of meters never used to be able to do. And it's a little bit harder to do those calculations. So again, bad at math. There is another error that could be made when trying to do those calculations. And it speeds up being able to do that job as well. Speaker 2 (13:05) Absolutely. And again, becoming increasingly more necessary depending on the type of work you do. So the HAC is a full wattage power meter. What other meters in the catalog also can do that? Speaker 1 (13:18) So the other one that can do our power factors and watts is our DL599. It's more of a meter. It straddles a lot of that commercial industrial realm for you because it also does, it has some three-phase motor rotation testing that it can do for you. You can make sure that, one, all of your legs are lined up properly, the L1, L2, and L3. But it also has a very simple pass-fail on the motor windings for you. So I know you've done the big formula to be able to calculate out. And then if it's down below a certain value, it's indicating that we are in the bad range. This is just a simple pass-fail. So if it's below that range, it tells you fail. So we're trying to make it as easy as possible to get the readings that you need to be able to do your job, no matter which realm you're in. Speaker 2 (14:13) Absolutely. Let's talk about some other maybe features on the meter that people don't use very often. Let's go to microamps. That's one that I think a lot of people get confused about is microamps. Some people will call it milliamps. That's a different animal. Milliamps is totally different. Microamps is even, as my granddad used to say, it's even smaller. amount of amps, 10 milliamps, itty bitty, if you will, amount of amps to be technical about it. So what's microamps typically used for? Speaker 1 (14:39) So a lot of times we're going to see microamps used, I see it the most in flame rectification. So when we're testing any of those flame sensors, it's such a small draw that they're doing. And the other thing with that is, again, we are talking about a very, very, very, very tiny, it's even so tiny, you can't just measure it through an amp clamp. you actually have to use your test leads. So by being able to get that, now we're going to be able to dial in and decide, is the flame sensor where it should be, or does it need to be replaced very easily with that? And I think the other thing is understanding what that symbol really looks like on your meter, because we're used to when we see the big A, that's our amps. But when we're starting to talk about microamps, The easiest way I describe it is it looks like a backwards lowercase u. It's reversed and it's a reverse lowercase u with your big giant A next to it. So that's an important thing. And that's a specialized dial feature because your meter can't range that far down through the amp clamp. Speaker 2 (15:49) It has to be wired in series with the actual circuit. So you actually have to disconnect one lead and actually wire it through your meter, which is weird. It's also a DC signal. So it's a DC amperage signal because flame rectification is DC. That's the rectification part. It's rectifying AC to DC. And you have that, like you said, that upside down U, that Greek, I think it's Upsilon is how you say that. Is it Upsilon? Something like that. Who knows why that means micro? I'm sure there's some Greek reason, but it's all Greek to me. That's generally what that's for. And actually, I don't know of another. I'm sure there are other applications for microamps. I don't know what they are, though. And HVAC flame rectification is the one that I know of. Speaker 1 (16:24) That is the one that I always talk about. So maybe somewhere in the comments on this, we'll learn that there is another application for it that neither of us just happen to know. So we'll look forward to that in the comment section. Speaker 2 (16:38) Indeed. Yes. Please tell us. Reach out. Email us. Email me. Brian at HVACRschool.com. And if you spell it Brian with an I, I'll still get it. But I will hate you forever because my name is spelled with a Y. Just a reminder. Very, very sensitive about this thing. I'm very childish. I Speaker 1 (16:52) understand. If anybody understands, have a name like Louise. Like Louise. Yeah. Yeah. I understand. Speaker 2 (16:59) In fact, I said your name to Leilani and sometimes I'll say Louise. And she's like, it's not Luis. Luis is if it was a Spanish gentleman. It's Luis. You have to learn this. I'm like, I'm sorry. It's like my aunt's name is Dawn. And I just say Dawn sometimes. And people can tell the difference. I can't tell the difference. Sounds exactly the same to me. I don't know. Whatever. Maybe someday I'll learn. If Speaker 1 (17:17) you get close and you're genuine about trying to get my name, I might probably respond to you. Speaker 2 (17:24) Probably. Otherwise, there's just no response. Speaker 1 (17:26) Who? Who?