All right. So uh, we're going to get into heat pumps. We're probably not going to make it all the way through heat pumps I Want to at least get into electric heat? I Guess First things first. So what is one of the first complaints that we get? As soon as we get into heating season, people start turn the heat on.

Burning smell. Good old burning smell. so that's why Early in the season and I guess for other other parts of the country, they're already well into the heating season. but for us, we're just now getting started as soon as it starts to get into the 40s at night.

and some cases, you know, kind of mid-30s that's when electric Heat's going to come on for the first time. Same thing is true with furnaces too. First time the furnace starts, people are going to get that burning smell. It's you know it's it's going to happen either way.

but what can we do to help prevent that for our clients? Go ahead. Elliot burn them off during maintenances. Burn them off during maintenances, right? And so a lot of times. And you know we have to make sure that when we're following protocols or checklists or processes that we don't throw the baby out with the bath water because sometimes you're going to be given a process or a procedure that's just is too much like it just doesn't.

It doesn't make sense I Give you an example, um, testing defrost every time you do a maintenance okay I can and and in some markets that actually makes a lot of sense cuz in some markets you have, you know you may have a cold, a cold snap in the spring or in the fall, and you may have a really, uh, really cold winter where you absolutely need defrost. But for Florida it's probably once every five years that Defrost even comes in to be a factor where you have cold enough periods of time. Um, that a coil stays Frozen Usually, even if it does frost over at night, by the time the day comes, it's going to defrost. It's not going to be a big deal, So for us to spend that additional time to test defrost every time we go do a maintenance just doesn't make sense.

It's not, it just isn't in Practical and I don't know of anybody who does it other than maybe like one technician you know here or there. Now that doesn't mean that you shouldn't know how to test defrost because it's still going to come in really handy. But the times that you're going to be testing Defrost is primarily that one and a thousand where you show up on a really cold day and You observe ice all over the coil, right? So that's just one example in heat pumps. but what? What Again, what often happens is we'll say Hey You Have to test the heat strips.

Okay, so how do we test the Heat strips Elliot Can't be the one to keep talking so somebody else, How do you Test The heat Strips. Crank up the thermostat until the heat strips come on. Crank up the thermostat till the heat strips come on right? Well, what's the problem with that? Sometimes it don't come on. Sometimes it's going to take a while for it to come on, right? Because you have, especially in modern thermostats, you have an algorithm.

In a lot of cases, you have a lock out nowadays where the outdoor temperature is going to lock out the heat strip. So there's all these things you have to de deal with just to try to get the stupid heat strips to come on. And here's the thing about heat strips. We don't really want them to come on.

We would be very happy if a winter went by where somebody didn't have to use their heat strips at all. Why is that expens? They're expensive, right? They're super expensive to operate. In fact, one of the number one strategies to reduce people's power consumption in the winter is to find novel ways of keeping them from running their heat strips. The number one way to keep people from running their heat strips is by not having big temperature swings, right? So this idea of temperature offset? That's the term manufacturers use thermostat manufacturers, Which means that when you're not in the house, you let the temperature go up or go down, and then when the house is going to be reoccupied, then you, then you bring it back to temperature.

That works pretty good in cooling season. in some markets here it doesn't even work great because of humidity, but in some markets that can be a real savings. But on the heating side, it's not a savings. It's absolutely not a savings if allowing the temperature to dri drift down in the home when it's cold.

and then when you turn it back on, you've got to turn the heat strips on in order to get it back up. Because heat strips are significantly more costly to operate than heat pumps. especially as heat pumps are becoming more and more efficient right? so that Gap is widening even more and more so we don't want heat strips to run that much. Testing heat strips can be tricky.

So how do I really want you practically speaking to test your heat strips? What's the practical way of doing that? How how a customer will do it? The thermostat that would be Again, that would be the best way you're going to jump hard to W right? That's that's what you're that. That's going to be one of the easiest ways to do it just to confirm that they do, come on and that they go back off. Go! Ah, so a lot of thermost these days. Actually, you can toggle.

just the oxed, even basic honey. Wells Have that there you go. And that's the other really good way of doing it. And probably the best way.

honestly um, is to just use your installer setup uh, or your your service test out within the installer menu in order to do that. And that's even true of things like the infinity controller. That's really easy. In fact, when you're doing a maintenance on a system on a communicating system like the infinity, going into that service test out mode and testing all your modes that way is going to be by far the easiest way of doing it.

Um, and that is better than jumping r2w. But I want to be really practical here. What we don't do is say oh well, the way to do it is so hard and so timec consuming that I'm not going to do it at all. This is the point I'm getting to here.

It may sound like I'm justifying bad testing practices. What I'm saying instead is is that you don't give up the good because you can't do the perfect or because the perfect is too timec consuming or because you don't know how to do the perfect. So making sure that you run the heat, especially in the fall, is really important. And not just the heat pump heat, but also the electric heat.

Make sure that it's working right. There's not some significant failure. Um, odors are really, really common. Customers are still going to be concerned, and so whenever a client is concerned about something, you cannot be dismissive about their concerns.

That's if you're dismissive overly dismissive, then they're going to think that you're just trying to bury something or whatever and so you want to. You want to talk to them as though what they're saying is a valid concern, but just communicate that yeah, all heating equipment the first time or two that it operates there is going to be a slight odor. if it is very extreme and especially if it's a maintenance contract, customer or system that re we recently installed then we should probably still go take a look. One of the worst things that I've seen and this was a house where kind of ignored what the customer was saying and eventually we went out to find that the installation instructions were sitting on top of the heat strips or other things I mean I found lots of different things on top of heat strips and it can be pretty stinky.

So or you know mastic got on it or there's there's all kinds of stuff that can happen that that will continue to be a problem and we need to be willing to address that. Now if you did want to see what was going on with Heat strips, what would be the easiest way way to find out? Pull the blower. You could pull the blower. that would be one way.

Yep, the other would be to pull the heat strips right depending on the brand um, and in carrier, that's both pretty easy to get Either out is pretty simple. I would probably just take the two screws out and just pop the heat strips out. but either way, um, it depends. It depends what the access is.

If you got a lotting type compartment behind in front of the the heat strips, then the blower can usually see what you need to see. Yep and then. And my point is is that you know like one of the worst cases that I ever had. I'm not going to tell the whole story because it's a long boring story but was in a bank where um I tested I tested the heat strips and they hadn't run probably ever and I don't know why fully, but they just hadn't uh and it just started billowing white smoke into the into the store.

So you do want to think about when you are testing heat strips even is there the possibility that these have never been tested? This is especially true in commercial applications, that sort of thing. And you also want to notify the client that you're about to do the heat test. So when you're there in the fall and you're going to burn off the heat strips, you want to tell them Hey today I'm going to be running the heat so you're going to get uh, probably get a slight burning odor while I'm doing that There nothing to be concerned about. The other thing that whenever we test heat strips and this is especially true when you're doing installs, uh, you always also need to make sure that they go back off again.

That's really important. It's always an opportunity when you're testing them for you to forget and leave a jumper in or whatever kind of what kind of thing and and leave it, um, running heat and that is a really really bad call to get a month later when they get their power bill. Now the good news is is that there the system will dehumidify. great so that's good because you then you have reheat and anyway I won't get into that again once we once you do test the heat strips, then you need to continue and do all the rest of your tests as well.

Um, one of the most important things. Oh actually and just to back up quickly. Um, how do you test heat strips? Like what is the actual process for testing heat strips from the thermostat? No, that's not sorry. What what I mean is is like what tool do you use to actually check he strips? You use an amp clamp, right? Okay, use an Amp clamp and where do you put the amp clamp on the wire you put amp clamp on? The Wire Going to the heat strips, right? The high voltage wire on on, just the high voltage coming in.

There you go and that's that's actually what I was wanting to get at. Is that putting it on the high voltage coming in, you're still going to know whether or not your heat strips are running. And the reason is is because heat strips draw a lot of current. So from two to 20? Real yeah.

So exactly. So you have just your blower heat strips. Come on. you could go from 2 amps to 22 amps.

like Jessica Just said really quickly. So it's okay to test it on the on the main line coming in and and we're not looking for Perfection here. A lot of guys get kind of silly about it. They're like, well, you know, 5 kilowatt heater.

You normally draws 20 amps and this one's drawn 22 or 21. like, whatever. Like that's not the issue. Obious.

You're really not checking it to see the specific amp reading. I have never once ever replaced a heat strip because the amp reading it was giving me was wrong. Has anybody else ever done that? I'm sure it's possible you have done it. It was giving me half the a reading it was supposed to.

It was a 15 KW it was a 15 KW 15 or 20 something like that. Okay, give me half two. Well, but that's then only it's CU Like only half of the strips were working, the other half was broken. Okay, Okay, I guess that makes sense.

Yeah, yeah, right. Okay, fair enough if you have a uh I like these classes. If you have a uh a 10 kilow heater, then you expect approximately 40 amps. You have 5 kilowatt.

Here you expect approximately 20 amps. Now this is another interesting thing. All right. So let's say because because I've done this I've made this mistake.

Let's say you, uh, show up to a job and you show up and you realize oh, okay, this this uh air handler only has the 30 or 35 amp breaker on it. The wire sizing is for a 5kw but darn it. I have a 10kw heater with me. Have you ever considered just disconnecting half of that heater and only running 5K See, this is maybe this is just an old school thing u I and and probably because of the whole like sticker reality nowadays it used to be that yeah, you didn't have stickers, you would just kind of write what the and so you could get away with that I guess I'm just expressing you never want to do that because what's going to happen is the next service Tech's going to come out.

he's going to see oh, it's 10. it's a 10 kilowatt heater and uh oh hey, how aren't working well? By golly, it's disconnected and then they're going to connect it and now you're going to overcurrent the Circuit So things like that, it's just, you know, don't um, don't do goofy workarounds like that And again, clearly I'm only talking to myself because some of you have even considered doing that. Um, sizing. Breakers And sizing wires is really important.

You can never just replace a breaker with a bigger size without also considering what the wire sizing is. This is a simplified chart. Um, so when you uh, when you look at this, number six is 55 amp and a lot of you'll be like, well, yeah, but we have number Six going to Uh systems with 60 amp Breakers all the time. This is for the lowest common denominator of wire.

This is basically if your Uh air handler is fed with RX and this is something you may not realize, but everybody knows what RX is. Rx is the the wire. That's where they're put together with the jacket. You know, the jacketing allinone.

Um, it's also known as NM or non-metallic Um, that that wire has a lower temperature rate than other types of Wi. So when you have a regular stranded wire that's in Carlex or seal tight, uh, or any other type of any other type of wire other than an M, you're generally going to be able to have a higher ampacity, a higher amperage capacity on that wire. So when people say things like well, a number 10 wire is 30 amps, that's if it's RX Basically, there are other types that are also that and I'm not going to go into all this, but we have a an entire article in description, different types of wire and what their ratings are. The point B being that for most of the types of conductors that are used for say uh, a 10 Kow heater, um, you can actually do a number6 wire.

Uh, and that's the reason why. if any of you have ever thought about this, it's like well, I'm putting a 60amp breaker on it. How does that work? The other thing is is that you size wires conductors. This applies to both Air Handlers and condensers.

You size the conductors by the MCA Okay, minimum circuit ampacity. So whatever that is, you have to size the wire to cover that and you size the breaker by the max maximum fuse size, maximum breaker size or sometimes they call it mocp. Those are two different things We don't have to know anything fancy other than that. Now when you see the MCA number and say that MCA number is 32 and the question comes, well, can I use number 10 wire on that? It depends on the type of number 10 wire at that point, if it's RX no, if it's one of the other higher uh temperature capacities than yes 75 CI 90 c not covering.

That's not what this class is about. All you have to do is just go back and reference uh the article on that and there's whole charts from the NEC that covers all that. but it's important to know that that's a thing and corre that you can go figure that out when you need to. You can find that answer right and generally it's not going to come up.

Generally, it's not going to matter, but when you have a 10 kilowatt heater and you look at it, it's like, well, my MCA is over 55 so can I use number six wire? That's when that starts to matter. And when it matters, it matters because it's about not burning a house down right? exactly To quote whatever band that is about. Burning Down The House You don't want to do it. They make it sound like a good idea, but it's not a good idea.

Jessica's laughing. Nobody else is I'm old, right? We're old, isn't it weird? All of a sudden you wake up and you're the old person in the room. You know what I mean Dre Dre put that song on when for his first Gr experience inside the house, Did you did you? It's good I Respect that, All right. So obviously you can't undersize.

Breakers You can't oversize. Breakers when it comes to air handlers especially. Um, C Can you undersize a breaker on a condensing unit? In some cases, this is not a trick Question: Can you undersiz? Yes, In some cases you can go. And by undersize I mean you can go below the max.

Now, inspectors don't understand this, so we just go with the max because we don't want to argue with them. Um, but you can actually do that in the case of condensers. In some cases, you really can't do that with air handlers. And the reason is is that the current that a electric heater draws is steady state.

it doesn't have Peaks it doesn't have valleys. It's just 20 amps. When that 5 kilowatt heater's on, it's 20 amps. When that 10 Kow heater's on, it's 40 amps and it's just that simple.

And it runs steady state. That much make sense and so because of that, it's not like you have this this starting current where you've got a little bit of flex there. It's like, okay, well we have a little bit of buffer, it's just bam, it's on or it's not. Uh, and so when you run in into a case where you have a heat pump and the inside breaker is tripping.

really keep that in mind. It could be a Msize breaker. But also like everything that goes into those heat strips because they draw so much current has to be really well connected. Um, one of the stupider things that I've seen people do is they'll have like a wire burns up or they got to remake a connector or whatever.

and they'll just use whatever size wire. Well, when you're talking about heat strips, it's just like the wires that go to your compressor. only worse because there ain't a compressor out there that draws 20 amps steady state. They don't exist right? Are not in residential? They may, they're going to Peak at times.

Why did I just say that? That is true that you you will get some I guess that are in that range but older R 22s and then also if you get like a um you have like an inverter driven system that's you know, screaming in heat mode you, you may get that, but you're not typically going to have that. So so when you think about um, what wires you're going to run to, even to the relays or contactors that could power heat strips, you just got to think about that. You can't just just pull anything, uh, off the truck and use it. Make sense Cool.

Um, the final thing that I want to talk about and I'm not necessarily going to go through this whole illustration here, but it's this concept of blower interlock. Uh, a lot of man, different manufacturers do blow or interlock differently and the the concept is is fairly simple and the mistakes that people make are also fairly, uh, consistent. So blower interlock is just the idea that, um, it makes sure that whenever heat is on, your blower is on and this goes back to a time when thermostats didn't give a g- call in heat. Um, and in many cases they're still set up not to.

And so what they wanted to make sure of is that if you have a W call that's bringing on your heat strips, your blower is automatically coming on and again different ways that this can be done, but one really common way that it's done is actually on the high voltage side through a relay. And the simplest thing to explain this is whenever we again this is a whole class in itself and and Bert may go over this a little bit more next week. Um, but whenever we wire up a relay, we often wire it up where we are used to putting power in on the one terminals. Uh, if you look at this picture up here, Uh, illustration number two shows you kind of how we typically wire up a relay where we put Power in on the one terminal and then we feed out to our loads on the opposite side of the relay.

But when you're using a relay for interlock, you actually imagine turning the relay upside down. Basically, that's the easiest way to think about it. and if there's nothing else that you remember from this cuz you're like I have no idea what you're talking about. Just remember that when it's time to wire up a blower and heat strip interlock, just turn the relay upside down and you actually wire in your power on the opposite side.

So in this case it would be in the three or the six is the side that it comes in and without getting two involved here. the reason that that is is to ensure that it's not going to do the opposite effect because we do want the blower to come on anytime the heat strips are on. But do we want the heat strips to come on anytime The Blower's on? No, we do not. And so if you wire it the other way, that can be an unintended consequence.

And that is a very bad unintended consequence. And when this comes in is when you're replacing generally a factory relay with something like a 9340 truck stock relay. And a lot of guys people out there would say, well, why would you do that? You should never do that. You absolutely can do it.

It's just a matter of understanding what the heck you're doing. A lot of factory relays can easily be replaced with aftermarket relays like a 9340, but you just got to know what the intent is and the intent is for the electric heat for the blower to be on anytime the electric heat is on and the opposite to definitely not be true. So what is the final step you do? If you've ever messed with the relays that do blower electric heat interlock, what's the last testing step you need to do? Need to R Blower and make sure your heat strips are not running. Absolutely, You need to run the blower and make sure that your heat strips aren't running.

You need make sure that they go on. You need to make sure the blower comes on when the heat strips are on, right? So run in heat. Make sure the blower comes on and then you need to put fan on only and make sure that your electric heat stays off. Make sense.

Yep, okay. um. another thing that's just worth mentioning is you may still run into some more old school systems that have heat sequencers in them. Okay, and a heat sequencer.

Uh, it. and I should have a picture up in the in the YouTube video. We'll put one up here. but a Heat SE Quencer is a type of relay that's heat activated and it automatically has a time delay in it.

And so because of that, if you're ever working with a system that has a heat sequencer in it, some people call it a stack sequencer. Um, you'll notice that there's a delay in both directions. There's a delay for the heat to come on, but there's also a delay for the heat to go off because it has a little snap action disc and it doesn't. It's not magnetically driven, so it's not like contacts that just open or close.

There's a little disc in there that's actually being heated up and then it eventually snaps and then it kind of resets. So it kind of does this this thing and that takes a little bit and so if you ever run into one like that and you're like these, he strips aren't going off. what the heck's going on? It's because it just takes a little bit to cool down before those, uh, return to the old position And the opposite is also true. It can in some cases it depends on the timings and so you can actually look up that relay and figure out what the timings are for the different Uh stages within that sequence.

So not a little bit like 3 minutes. Not a little bit like 3 minutes, right? right? Not a little bit like half an hour later these heat strips are still running and again, the the the worst phrase that technicians will say is I think that's normal I Think that's normal. You have to know if it's normal or not and you have to make sure that it's right before you leave, right? and that it's that impulse that we get to say like ah, I don't have time to deal with this right now, but things like your electric heat staying on all the time, you definitely have time to deal with that because that's a very expensive problem to run into. All right.

So when it comes to electric heat heat kind of top things. we do have to make sure that we test it on installs. We have to make sure that we make sure that it goes on. We have to make sure that it goes off when we do our fall.

PMS We need to make sure that we operate those heat strips at very minimum, even if it's just jump ring it out. That's better than doing nothing right. Same thing is true with gas furnaces too. I Didn't mention this, but obviously we need to be operating that gas furnace and we need to be doing all this test protocols that we just talked about.

We're going to be doing a lot more gas furnace testing, um, a lot more gas furnace training as well. So whatever things you're used to doing right now on that front, we're going to be doing a lot more of Um with electric heat. It cannot get more easy in terms of the technical aspect of it. It's very simple: you apply power, they heat up, but when in doubt, pull the blower out, pull the heat strips out, actually, physically take a look at them, make sure that you're burning them off if it seems like too much, take a look, um, and then make sure that if you are doing any changes at all in the actual high voltage wiring, relays, connections, Any anything like that that you ensure that you test this and make sure it's working properly.

All right, any questions about any of that? anything else you'd like to add BT I Feel like I Just kind of incomplete? Go ahead. Um, just that this is more of an older setup. Um, with the blowers now pretty much all being x13, you can't interlock the high voltage and bring on the blower and so you can use the relay on low voltage that if W calls then the the lower calls right? Um, so you can do the same thing with low voltage. That would be a more common setup today.

Yeah, correct. And then the other setup is they're also just tapping straight into the speed of the blower with white. More and more your your 24 volt calls are just going straight to the blower. So the blower is actually just looking at what's calling and that's how it's operating.

and again, we're in this kind of weird state where when you're a service tech, you're going to be seeing a lot of stuff like this still. Um, but when you're installing the newer things that are coming out, you know it's all of this is pretty much going away. It's like talking about charging A system that has a fixed orice and how you charge by superheat. You know those are pretty much all not all gone, but but mostly gone at this point.

Um, and then it makes it a problem though. and this is why it's still important to train. Because the less you see it, the more likely you are to totally screw it up when you actually show up to do it. The same thing is true if you show up on an R22 system, forget to pay attention and start adding 410A to it.

and and again that happens. more the less you see something and so it's important to still have in your head and the more things and this is just a kind of a final a final tip here. the more things that you're expected to remember, the more likely it is that you just do that. Ah, it's probably fine thing and what I'm saying is, you don't have to remember everything.

You don't have to remember how to do this. I Can guarantee you you're not going to remember how to wire up a 9340 for blower heat interlock. but we have this nine panel. This is just half of it.

Here's the rest of it. We have this nine panel that shows all of this and when you first look at this, even it's going to be like oh, my brain's melting, right? But you just got to go through the steps and read through it and it will make sense. Then all of this stuff exists. Okay, this is also one of the checklists uh, that exists on the HVAC School lab.

So everything that's a nine panel that we do like this where it's a square also has a checklist on the app. and just again. I'm not saying it doesn't have to be my app. If there's something else out there that shows you how to do the same thing, use that.

but don't just say I Remember there's something about this, but yeah, it's fine cuz again, those can be very, very costly. Um, costly things. So wire sizing is important, knowing when to go look at wire sizing and also knowing when to um, stop and figure out what you're doing there. But testing is always the key thing because if you even if you do screw it up, even if you do wire something wrong and you test, you're like uh, feat strips aren't going off then you can.

You can easily find that. Figure it out. So ell's getting a little too excited over the3 relay as a te strip. There you go.

Yes, like I did and melted it. Yes, that's right I do remember um this very conversation the 90 uh that this that this relay had some important uh job related to the heat strips. and so when I found a failed heat strip relay one of my first on calls I decided to put a 93 relay in there. um because that was so much smarter than using a cont contactor on my van.

but they're rated for like 14 in y Max Yep, in fact, that's one of the ways if you've ever thought about this like what makes a contactor different from a relay like cuz they really kind of do the same thing. They have an electromagnetic coil. they pull contacts in and out. Um, generally speaking, a relay, at least in the residential world is something that's 15 amps or lower contact rating.

So that means that for compressors and heat strips, no bueno, You cannot use a relay for those. Relays are generally used for low voltage control. Um, you know, passing power for low low voltage purposes or for what we do like a blower. That's pretty much all.

They're good for heat strips, compressors, you're going to melt them. So yeah, and again, that's just paying attention to the current rating. and this is something that even things like using wire nuts I'm just going to end here. but like just using wire nuts to put wires together, it's like hey I got a wire nut that that the wires will fit so we're good right? Not necessarily that wire nut has a rating, it has a current rating and it also has a rating of how many wires can go under it.

Um, same is true of every conductor. So I don't expect you to know all that stuff of us do, but you just have to stop and say is this, does this look right like Am I doing something that makes sense here. Um, and yeah, it is going to be on the package right now Again, you may not always have the package and all that, but that's just where it's best to. It's best to stop and think about it, and especially as those currents increase.

When you're working on you know, 10kw or even in other markets 15 20 kW Heat you got to really start thinking about those main connections that are coming into that. Appliance You know are they going to handle this? And that's why many cases you end up going to separate circuits. you'll have a you know, one circuit that powers one set of 10kw and another circuit that powers the second set. Um, just always thinking about that.

Like wire size connections. Um, all of it. Those all have ratings. You may have really good wire, but if the connections that it's coming into aren't rated um for that additional current, then those connector.

those connectors will melt. In fact, that was one of the things that I used to see a lot with heat strips. Back in the days you'd go in and the wire nuts would just be all melted off. And it was often because sometimes they just didn't make a good connection.

but in a lot of cases they were expecting too much of those wire nuts. Cool. Awesome! Bert's going to be here next week I'm on vacation so it'll be a lot more fun. Thanks everybody! thanks for watching! If you're willing, give this video a thumbs up and drop us a comment.

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