LS ELECTRIC America - Boot Camp Session 1: VFD Applications

Summary

The session delves into the practical applications of Variable Frequency Drives (VFDs), led by Dave LaRue, the Eastern Regional Sales Manager for LS Electric. Spanning a career of over 37 years, Dave shares his rich expertise from Maine to Florida, unpacking the intricacies between constant torque and variable torque in varying systems. Emphasizing industry examples and cost-saving insights, attendees are equipped with advanced understanding of VFD sizing and programming, highlighting key differences in applications for pumps, fans, and conveyor systems. Additionally, upcoming boot camp sessions are introduced, promising further exploration into VFD programming and PID basics.

Highlights

• Dave LaRue shares 37 years of VFD experience in an engaging boot camp session 🎓.
• Explore the financial benefits of applying VFDs to reduce energy consumption in systems 🌍.
• Discover how to tackle VFD complications like overvoltage with dynamic braking solutions 🔍.
• Upcoming sessions promise to expand on practical VFD programming and PID use 📅.

Key Takeaways

• Understanding constant vs. variable torque is crucial for VFD applications 💡.
• VFDs significantly reduce energy costs in pump and fan applications, leveraging the affinity law 💸.
• Dynamic braking and regen solutions are vital for managing overvoltage in VFD operations ⚙️.
• Proper VFD installation and motor choice mitigate reflective wave and capacitive issues 🔧.

Overview

Dave LaRue, a seasoned player in the VFD field, kicks off the boot camp with insights into the differences between constant and variable torque. His background echoes across three decades, promising a session filled with practical knowledge and engaging industry-specific stories.

This session unpacks the power-saving potential of VFDs in industrial applications like pumps and fans. Attendees get a deeper look into the affinity law and how it translates to significant energy savings—a hot topic for any industry looking to cut costs and reduce environmental impact.

Key technical challenges, such as managing overvoltage through dynamic braking and understanding motor compatibility, are tackled. As the session wraps up, Dave introduces future sessions on advanced VFD programming and PID basics, hinting at more knowledge and skills to be gained.

Chapters

• 00:00 - 00:30: Introduction and Speaker Background The chapter introduces the speaker, Dave LaRue, who is the Eastern Regional Sales Manager for LS Electric, covering the area from Maine to Florida and up to the Mississippi. Dave mentions having over 37 years of experience, primarily as a drafter. He addresses some of his customers present in the session and notes that this session is new to him and will last about an hour.
• 00:30 - 05:00: VFD Applications and Functions This chapter introduces the topic of Variable Frequency Drives (VFDs) and their applications. It begins by setting an informal tone, inviting questions from the audience. The key focus is on understanding the difference between constant torque and variable torque, and how this distinction affects the sizing of the VFD. The chapter ends by mentioning a previous presentation by someone named Steven.
• 05:00 - 10:00: Energy Savings and Cost Analysis The chapter "Energy Savings and Cost Analysis" builds upon prior knowledge of DFT (Drive Frequency Technology) operations, specifically its role in converting AC to DC, accessible via online platforms such as YouTube. It focuses on the nuances of constant versus variable torque applications, emphasizing their practical application in systems like pumps, fans, and conveyors. The text implies a continuation from basic principles to real-world applications, aiming to clarify the distinctions in various torque scenarios.
• 10:00 - 15:00: Pumps, Fans, and Compressors In this chapter titled 'Pumps, Fans, and Compressors,' the focus is on understanding terms related to Variable Frequency Drives (VFDs) and their application. Specifically, it covers how VFDs are identified in price sheets by others and competitors, distinguished by constant torque and variable torque ratings. The chapter explains these terms by illustrating the overload capacity that a VFD can impart on a motor within an application setting, using a 100 horsepower constant torque as an example.
• 15:00 - 20:00: Torque and Load Considerations This chapter discusses the concepts of torque and load, focusing especially on variable horsepower ratings. It highlights how the rated amperage at 125 horsepower is 150 amps, compared to 183 amps. The chapter also talks about the importance of the 150% rating to manage initial loads and handle situations involving shock loads, enabling machinery to start efficiently or cope with sudden strain.
• 20:00 - 30:00: Advanced VFD Features and Demonstrations The chapter 'Advanced VFD Features and Demonstrations' discusses the ability of Variable Frequency Drives (VFDs) to handle overload conditions. It highlights that a heavily loaded VFD can manage up to 150% of its capacity for one minute, translating to 228 amps on a 100 horsepower drive. When rated at 110% for one minute on a 125 hp drive, it can handle 219 amps, illustrating the importance of selecting the correct VFD for variable torque applications.
• 30:00 - 40:00: Installation and Troubleshooting The chapter discusses issues related to the installation and troubleshooting of motors and conveyor systems. It highlights a common problem where the motor lacks sufficient overcurrent and torque to start a load effectively. An example is provided where a distributor sold a 300 to 250 horsepower variable torque rated VFD (Variable Frequency Drive) for compressors. Even with a 350 horsepower system, there were still issues.
• 40:00 - 50:00: Reflective Wave and Motor Protection The chapter titled 'Reflective Wave and Motor Protection' discusses overcoming pressure differences in systems. It highlights a scenario where a system runs efficiently at 89 pounds of pressure but fails to operate at 92 pounds, despite the minor difference in pressure. This signifies the importance of accurate sizing between constant and variable systems, which is based on the overall RV (perhaps referring to a technical term or variable not fully explained in the transcript). The discussion suggests technical adjustments and considerations necessary for proper motor protection and performance in varying pressure conditions.
• 50:00 - 59:00: Conclusion and Q&A The chapter concludes with a Q&A session where the main discussion revolves around different types of duty ratings for lineups. It highlights that most lineups are designed to work for constant variables, except for a few exceptions. The conversation specifically compares the heavy duty or constant torque ratings between models, mentioning that the "G 100" model is suitable for both heavy and normal duties with a higher rating of 120%, whereas the "is-7" model is only rated at 110%. The "s100" model also has a rating of 120%, making it suitable for heavy-duty operations.

LS ELECTRIC America - Boot Camp Session 1: VFD Applications Transcription

• 00:00 - 00:30 alright guys I guess we'll get started hmm like I said this is new to me doing this I'm Dave LaRue and the Eastern Regional Sales Manager for LS electric cover from Maine to Florida to the Mississippi so I have some customers here and I'm trying others mm my background I said I'm an old man they're doing this for 37 years then the draft guy and most of those 37 today it's only gonna be about an hour
• 00:30 - 01:00 and I'm gonna touch on a few things you guys have any questions hit me up on the chat monitoring on that on the side so very informal let's get started what we're gonna talk about first is the difference of a constant torque and variable torque in how you size the VFD there's a Steven did a presentation
• 01:00 - 01:30 prior on the basics it talks about how a DFT operates and now it converts ac/dc and that is on our YouTube in a most everything we're doing now and we do these training classes you'd be able to look at that and get it off of YouTube as well so now I'm not gonna be talking about the basics aspect so we won't talk about is the difference between constant torque and variable torque and applications applying two pumps fans conveyor systems go on and so forth when
• 01:30 - 02:00 you see in our price sheets it's known to us as others and competitors you'll see constant torque and a variable torque rating what that means and what it breaks down to is the amount of overload or percentage of overload that the VFD will apply to the motor in an application so as an example I'm showing you a 100 horsepower constant torque
• 02:00 - 02:30 which is also rated 125 horsepower variable tour you'll notice the rated amps is only 150 - versus the 183 so that being said you'll notice at a hundred and fifty percent and that's usually for one minute and what's that's for is to get loads up and running or if you're in a shock load something's
• 02:30 - 03:00 heavily loaded overcome inertias maintain speed or torque you have a hundred and fifty percent for one minute so with that overloads you're looking at two hundred and twenty eight amps on a hundred horsepower but that same drive rated at one hundred and ten percent for one minute on one hundred and twenty five is actually only two hundred in nineteen eighty so what that means is if you put a variable torque rated VFD on
• 03:00 - 03:30 125 horsepower motor and you're running a conveyor system you may not have enough overcurrent or the ability to generate the torque to be able to start a load I'm just going to use an example recently and I had a distribute or sell a three hundred 250 horsepower and we'll talk about compressors later that was a variable torque rated VFD we got in 350 horsepower but it was unable
• 03:30 - 04:00 to overcome the load at 92 or 93 paddles of pressure in the system whine it run at 89 but it wouldn't run at 92 you would think he pounds of pressure would make that world of difference but he didn't so he definitely had to take it back but when you're sizing constant versus variable what you're doing is you're sizing based upon the overland RV
• 04:00 - 04:30 ft lineups most all of them are constant variable to work except for one hour small single things rate it's heavy duty or constant torque rating the G 100 is both heavy duty and normal duty which has a higher 120% rating what I just showed you in the is-7 on the is-7 is only good for 110 percent and the s100 is good for 120 in our age
• 04:30 - 05:00 100 it's a it's a fan in pump drive and it's rated 420 % for 60 seconds once you get above 125 for ferrets only 110 percent now that's not to say you can't oversize a variable torque drive to be able to handle heavier loads it all goes back to these type of scenario and so if you adhere and I needed to do 100 horsepower worth of load of 228 hams I
• 05:00 - 05:30 would oversize to a 150 horsepower variable torque and probably could get by doing now we also have a couple of other programs coming up basic VFD programming that's on April 30th and then on the electric LS electric boot camp PID basics that's gonna be May 7th reason I'm bringing this up is I'm going to be talking about pumps and fans order that
• 05:30 - 06:00 is that people yelling at me I guess trying to give in to the webinar sorry guys I'm not going to talk about how the process works PID proportional integral derivative which actually there's no derivative in there they will be talked about in later classes on how you manage pressure and flood so we're just going
• 06:00 - 06:30 to talk about the actual applications themselves why do we put fans and pumps PFDs and fans and pumps basically it's all about money there's a thing called an affinity law and if you actually look I'll show you some curves later you look at operating a fan at 80 percent rated saves almost 50 percent of the power of the fan itself
• 06:30 - 07:00 engineers are god-sent they can do a lot of things but they're not going to be able to Sundays a pump or a fan system to be exactly what is needed for that particular application and without it having either understands that or oversize most engineers or all engineers I know they always design their systems above what is required to be able to
• 07:00 - 07:30 handle the applications so you'll notice in this chart on the centrifugal pump eighty percent flow of at 80 percent speed 52 percent power at 80 percent speed that's the curve or what's called affinities law that means operating or you actually don't need to operate at a hundred percent in most applications what they do is they usually type of either a throttling valve pressure
• 07:30 - 08:00 relief diverters things like that to be able to handle if you're running across the line because the pumps is going to run in 1800 rpms being able to lower the speed of the motor to meet the actual demand you'll notice you'll gain almost 48 percent power reduction in that and what that means is dollars this is just
• 08:00 - 08:30 some stuff I googled yesterday to put in the presentation just to give you an idea of the cost across the East Coast knew I didn't go into Massachusetts because I think they're even higher up that one but New York's at eighteen cents a kilowatt hour and you'll notice it it goes down until you get to North Carolina and then back up again as you move into Florida so you can see that can be fairly expensive if we use north of New York as an example and I'm gonna
• 08:30 - 09:00 run 100 horsepower now this is extreme 365 days a year but it can you know we have software and it can be calculated on the energy side engines actually h100 rather will do that for you Oh any working at 24 hours a day a cost well over a hundred and twenty-five thousand dollars to operate that that VFD 365 days a year so if I'm running an
• 09:00 - 09:30 80% loaded on just the simple math that's $20,000 in energy savings in that particular application if you take that into your accounts or you know into your plans or so on so forth and you walk around and look at how many across the lines and it's not only just the small you know larger boat or small butters 10 horsepower our 5 horsepower that all cost money so you can see you can save a
• 09:30 - 10:00 great deal of money by using the F T's in these types of applications hands are much the same what you'll see it's a centrifugal fan though the curves upon curves going deep almost identical you have flow pressure and power as the speed increases of course more power is required to do the same thing and what they use to handle that our products called dampers now what you'll see is
• 10:00 - 10:30 you'll have an inlet nap or an exhaust damper you'll have in-line dampers that would have say pressure of flow meters of pressure meter so on and so forth what that is done is what you do is that would be feted or operated either externally by some type of input controller and then the pressure or flowed with feedback to the controller which then move the damper again the VFD would be operating across the line as
• 10:30 - 11:00 you can see it an hour possibly higher because it's building pressure constant by removing or opening the damper bringing the flow back to the VFD in running a PID loop in that in setting your setpoint the air pressure or the amount of energy used is dramatically different lower oh sorry the gotchas
• 11:00 - 11:30 when you're doing pumps you'll run across each either centripetal or a positive displacement now the different is on a centrifugal pump you'll see here is the flow actually really doesn't start pumping until you get approximately 30 Hertz or half speed and then from there the flow will pick up you're slinging it is with the terms and terrifical pump is but when you get to
• 11:30 - 12:00 a positive displacement pump what happens now is each rotation of the shaft or whatever the driving mechanism is bills pressure internally into a piston environment or something like that to where the suction valve closes the discharge valve opens so every time it goes around we're required to use the same amount of torque with the same amount of energy to be able to pump that
• 12:00 - 12:30 so why would I do that well what happens is you get you get some metering oh it's great for higher viscosities or high pressure applications well thing is is the affinity law does not come into play with the positive displacement pumps it's a constant torque application a hundred percent of the torque or whatever the value is to run it doesn't
• 12:30 - 13:00 change even impulse you know once you get above full speed if you're over speaking you get into what's called a constant horsepower conformation and then the torque will drop off at that point so you have to be careful so the guy says that I want to put a VFD on my palm your first question begins should be is it's in Tripucka or is it positive displacement because if it's positive
• 13:00 - 13:30 displacement you have to make sure you apply a constant torque style of eft mixers are another one um I have done some mixers where I got scared when I showed up because I sold a variable torque and got the error and it had changing viscosity that'll be in something you as simple as if you're stowing to all bakeries where they drop
• 13:30 - 14:00 flour or water and the dough changes consistency so you may start off at a load torque requirement but then as it changes or it moves the viscosity change I had 13500 horsepowers to Merc in the Senate ovale for their batching on drugs and viscosity and the material would change the process of it start out approximately less than a hundred
• 14:00 - 14:30 horsepower worth of requirement but at the time of the end of the 72 hours of process it would be almost rubber it would be that much of a change in difference that's why we had to do the 500 horsepower and that's even including gearboxes the mixers I would always use constant for air compressors goes back to the one that we were talking about I talked about earlier on failure um it was a constant torque or reciprocating
• 14:30 - 15:00 displacement you hear the precipitating that's the same charm for positive displacement again you've requires a lot of torque to overcome them the head or the load or unloading pressure a lot of times these air air compressors and these people will run these motors in the service factor I don't know if you guys know what service factor isn't not but you have one point of service factor when you operate on VFD a motor can have
• 15:00 - 15:30 one point one five or 1.20 and what that means is if it's as an example I'll use a hundred amp motor with a one point one five service factor the motor can actually operate in one hundred and fifteen amps and still operate fine but when you put it on a VFD it's 1.0 unless you oversize the DFT to make up for that service pack the variable torque are usually a rotor screw you can time for
• 15:30 - 16:00 vanes much like centrifugal pump but again always confirm with the manufacturer the Baker is definitely well welcome back systems there is usually in that toner I think's been telling me that for a year and I still can print with it they're usually fairly straightforward if the motor will run it's constant torque it'll move it in bounce screw conveyors you know you have
• 16:00 - 16:30 to be wary of depending upon what the loads are such things or some type of material like that if it starts to harden up you have to make sure you have enough torque to be able to overcome on the loads inside the screw conveyor Rock conveyors you may have to start that motor in a rock quarry where that say they had a problem with a V belt or something at the top and it's topped with a anti rotation device back
• 16:30 - 17:00 rotation device and you may have to start those lugs they may require a dish oversizing of the VFD in that I made the comment of prophylactics - Twinkies I've done both I actually put VFDs on a prophylactic machine to help with the dip how long it was in the dip to allow X amount of material to make sure it had enough material placed on to the mold
• 17:00 - 17:30 Twinkies I did a system in Richmond where we had to maintain a certain amount of time in the bakeries with a simple time for the VFD system so I mean babies are in the industrial world or break for you know couldn't process control and applications another one is something here is shaker conveyors I've done quite a few of those in Southeast Georgia with the peanuts people there's other people you shake
• 17:30 - 18:00 conveyors to move product and such well you have to be careful with this application what happens is a lot of times these two Malaysians are these shakers oh yeah I did I'm laughing in chancery guys um where they have eccentric four concentric I don't know which particular word to use but it's it has an over running load and what will happen is you will get a over voltage
• 18:00 - 18:30 situation now what will cause that is the VFD will see the motor is an over running condition you know people use edges of your car driving downhill and you're having to put the brakes on well actually on a VFD once it sees an over running condition it is trying to keep it from being an over running condition so it builds its PCBUs you try to do
• 18:30 - 19:00 work and as it builds its unable to stop the rise the DC bus so once the DC bus reaches a particular voltage you will get a trip you know some of them are all over the place some can be 750 others can be 800 850 volts the drive does that to protect itself plus the capacitors and the drive that's what causes the over voltage tripping now punch presses I did one for a distributor in New
• 19:00 - 19:30 Jersey it was 350 horsepower on that you'll notice that large wheel right there and as it comes down you're become you're getting into the regenitive or the move or the function of the punch press but once you hit the punch press hits now you're driving it back up it's much like the pump jacks that come out in California and not
• 19:30 - 20:00 California but Texas and Oklahoma they have a problem with those types of things as well tell me back oriental solutions this is how you solve these types of problems it's a nice little feature you know I'm bragging on the drive down is we have a what's called a region avoidance and what it does is it will monitor the DC bus and you can say here
• 20:00 - 20:30 and you can set it up in simple parameters I'd only think it's like four or five parameters that's need to be set if it sees that the DC bus reaches a particular level will cause a 700 volts the drive will actually speed up and what it's doing is instead of trying to hold the motor back it speeds up to catch where the speed is so thereby it doesn't require higher DC bus to do work
• 20:30 - 21:00 the DC bus will drop you'll notice there's I mean there's a safety function you don't want it going too fast over and it'll have a over speed trip firing 50 percent based it's that max frequency now we're not talking about this over speeding for a minute we're not talking about it over speeding for five seconds most of these times or most of the over speeding is in a very short period
• 21:00 - 21:30 this is a better chart to explain but if you sit here and I've done this with our software we have a very good software that does this our drive you now so here's a reference frequency and all of a sudden I'm seeing a problem where I'm beginning to rise on the DC volts and the region avoidance at that point senses it and then speeds and here's your output frequency see how it comes up it senses where was it okay okay you
• 21:30 - 22:00 know sense that the it speeds up to override that region above Wiggins and then comes back down again I've used
• 22:00 - 22:30 that I've used it in these punch press applications or these shaker applications Stephens done them as well they may work extremely well the punch press you have to be careful um it's great when it's running it'll drive through it but if you do a a very quick change in speed you can still at that point still find yourself in a situation where you're getting over both
• 22:30 - 23:00 trip that's one way of software when the next is actual dynamic braking now what dynamic braking does is you will have a rise in DC voltage and those types of situations that causes the DFT to trip you don't want it to trip and as an example you take this Lawrence force deduction man that's a lot of inertia
• 23:00 - 23:30 that you know you're running at 60 Hertz or 55 Hertz when you want it to slow down if you begin to hit the D so again the drive tries to speed up to catch the load and as it does it could trip so you would say all right I put out a loan 602nd decel right well yeah that will eventually work but most people do not want to stop a fan in ten minutes so that's the issues that has to do with
• 23:30 - 24:00 production how quickly to brew safely to bring something to stop so then you would begin to use dynamic braking now we have other in other companies Heather - there's other solutions again within the drives themselves it's called we call a power braking and what you would do with that it's as the DC voltage Rises again it's monitoring the DC volts it applies brakes or it tries to stop
• 24:00 - 24:30 the motor rotation and then but what happens is if it's since it's it's going to go trip again trip it will let the motor Coast a little bit again we're talking microseconds or nanoseconds not down of the micro probably milli seconds and then catch it again stop yeah that's it again stop catch it again now what will happen even if you said say 10-second DISA don't it still may take a minute to stop that load and
• 24:30 - 25:00 you really don't know how long it's going to take until you do that what the drive is doing is it's going to do its best to stop without overpowering the drive or that trip but again that's a software solution another type of application of dynamic braking is in sawmills you'll notice how this particular law carriage goes back and
• 25:00 - 25:30 forth now a lot of these are done hydraulically but that's again limited in speed because you can't really bear it but so much and cost a lot of energy to run hydraulics for probably 60% efficient with a hydraulic system so you're taking that massive load and you have to stop it notice how quickly they stop it and then starting in reverse and come back that's a lot of loading so that's another area where you would
• 25:30 - 26:00 use dynamic writing could be able to start to stop a motion like that now how do you do now any braking dynamic braking what you're doing is in this symbol this is the SCO our diode front end you'll be generating a c2d City and it comes across a pre-charge circuit the pre-charge relay and what this symbol is showing is what's called capacitors you're charging those capacitors within
• 26:00 - 26:30 the circuit it's usually 40 horsepower and below for us we have a transistor another IGBT and insulated gated bipolar transistor that then as a monitoring circuit that will open when it senses it gets to a particular level so then it opens the circuit that you would come in p2 and B and you would hang also your second you would hang some type of resistor and connect fret connect to the
• 26:30 - 27:00 drive of itself and we'll talk about resistors here inspector the smaller their feeds they all come with this built-in transistor you get into larger units above the 40 horse powers there's things called we call them dynamic braking units what they do you look here is they'll connect directly to the DC bus and they in turn of monitoring this external device is monitoring the DC bus
• 27:00 - 27:30 and then it determines when to drop across the resistor these are current rating so when you're getting two larger horse powers they could require multiple units in series to be able to offload those types of loads and resistors you wire into the DC bus you're running across a resistor so then you have your dynamic braking these resistors they
• 27:30 - 28:00 sized based upon the loads and what's needed based upon Watson okay they can come in you know in an open situation where you can mount of them say in a separate enclosure I would not bound an in an enclosure with the VFD because basically the resistor is your electric heater most times of being an even one configuration you can mount them externally on top of the drive package or what when I say drives and Watson
• 28:00 - 28:30 ohms there's also a thing called a duty cycle and what a duty cycle means is how often you want to stop what you're doing so if you look at the cinemas may be hard for you guys to see you will see a hundred percent IDI is that percentage of IDI is the duty cycle you'll see one hundred percent you'll see five percent you'll see ten percent and you'll see 15 percent now there's also not only these
• 28:30 - 29:00 duty cycles but they are also sized based upon the amount of torque or the amount of current that's going to run through them you'll notice this is a minimum but here is a maximum saying that we're going to give you one hundred and fifty percent so you have to determine the duty cycle and what a duty cycle is as you break it down into an hour and use that as an example if I'm going to start and stop this load once an hour and a five percent duty cycle
• 29:00 - 29:30 it's fine it's not an issue if I'm starting it by 10 times starting and stopping five ten times an hour then you're starting to look into the higher duty cycle Oh Kevin over there um so what you'll do is you'd have to look at maybe the 10 to
• 29:30 - 30:00 the 15 percent um you have a situation on the punch press think about that every time that comes around that could cause issues so that's every revolution that would be almost at a hundred percent on duty cycle I'm going away sorry guys but that would
• 30:00 - 30:30 almost be a 100 percent duty cycle and what happens is the own values really you know they don't really change that much what changes is the watts you know minimum is here is 123 ohms at a minimum while like a 5 person or a very small duty cycle those is 317 percent but it's 530 watts at 100 percent versus 53 at
• 30:30 - 31:00 ten or twenty seven and five what that means resistor up you'd have to have enough capability to handle both the while the heat and the ants running through those resistors there's another function called regen what it does at that point is instead of dumping that energy and wasting that energy across
• 31:00 - 31:30 resistors um continuously or you know doing a dirty duty cycle will have a your company will have a regenerative device that basically has the same device on the output of the VFD which is an IGBT device that is connected directly to the inverter itself and it will take that DC voltage and it will create AC voltage much like it does
• 31:30 - 32:00 on the motor itself you know it's not designed to change to eat or anything like that so the circuitry and the additional components and controls and things like that it's less because you're only gonna operator to 60 Hertz and a set voltage level so it's gonna come through and what you want to have is some type of current suppression or impedance in the system you know that way it chops off Peaks we'll talk about that in a little bit that then feeds
• 32:00 - 32:30 back onto the lab I recently had a crane manufacturer that came to me because they are the federal government's changing the energy standards for cranes for lift motors because cranes are usually you know 50 percent or 20 percent want something to be approved um
• 32:30 - 33:00 plain women um so you know he was looking at weddings to overcome the energy failure energy savings um because he was dumping across a large Bank of resistors so that's where the energy aspects can come into play you know how much is it going on you know put back online I um depends on each particular application um but it is you know it can be a cost effective device um to be able
• 33:00 - 33:30 to save money versus having large resistor by physical space maintenance so on and so forth and and in the future as a cost of the odds of UT's come down you're going to see more and more No don't murder you alright um again this
• 33:30 - 34:00 one kind of got stuck in here but I'm use this as an exotic conveyors conveyors usually fairly you know you'll have screw conveyors prac packaging conveyors but there's a couple of gotchas this was not too bad not dude in here but I've seen a lot worse always I ask to you you know how many our pubes there are in
• 34:00 - 34:30 the motor itself mm-hmm if you're at eight thirty six hundred or a two-pole motor you know it's going to have less RP or less amps so it's gonna run about 111 in you know 4-pole will have a little bit more so on and so forth all the way down the state 900 rpms what you can notice is rather a dramatically larger you know I'll give him that line up nice 1 million cheap project no it's a de novo or Nashville
• 34:30 - 35:00 Tennessee worked with Hazen and Sawyer the engineering group they sent out this big spec I knew there was you know several large 400 horsepower motors to be driven by the FDS but they were 600 rpm motors and I knew it and I bid the project and I bit to the amps and that's where I do too much I actually lost the project because I kept screaming at
• 35:00 - 35:30 everybody the contact on contractors and everything else but my competitors were not sized properly which time to find out I was correct but you have to you know make sure of the amps on the motors that you know VFDs don't really care about horsepower take care of that in amps so that's which was real looking for they different types of motors and what you need to know and how to apply them on VFDs you don't see these as much
• 35:30 - 36:00 as you used to used to see a lot of these Lincoln used to make a multi guard that was also umberto rated film encapsulated I loved it London's good motor but what you're looking at is how much and how it can operate or immerse when you start changing speeds I'll talk about it I'm filming close fan cool here in a little bit but when you charge changing speed it can cause issues with the motor constant torque you know some
• 36:00 - 36:30 manufacturers say they can go down to four to one meaning that if I'm at 1800 rpm like I'm with that say 5 or 85 450 RP use and still maintain constant torque without burning up the motor I would never run it up and drip proof that level and then tend to wounded variable torque you know what that means is if I can run from 1800 rpms down to 180 rpms but it has to be variable torque meaning the amps at the
• 36:30 - 37:00 lower end are not as high as it is on would would be a constant torque device okay well excuse me most times you'll see these applications on pops so they're they're pretty much going to be available for installation closed very cool um now again the EPAct standard this came into play at 97 1997 and what happened was
• 37:00 - 37:30 the energy group or the US government set energy efficient standards for motors if you guys think about it what is the biggest energy user on a totally enclosed and cool motor it's not the frictions and the bearings you know you're talking about in terms of usages it's the fan on the back of the motor that actually uses energy so what motor
• 37:30 - 38:00 manufacturers have done to meet the efficiency ratings is they've used a higher class insulation more copper windings smaller thomas' between the stator and the rotor but by having a smaller fan in lower rpms and lower air movement it saves energy and efficiency of the motor but by doing that when you operate in a constant torque environment it can cause issues because the fan is not moving a lot of air oh you'll notice in some motor
• 38:00 - 38:30 manufacturers on it Baldur's one of them marathon does it they will have a note that says they can do four to one or ten to one constant torque but again with a fan change so that means that they were put in a larger fan on the back of that motor vehicle to end of one constant torque and with these again the 20 to one you're down to 90 rpms but again but
• 38:30 - 39:00 variable torque you're not seeing a lot of current at that low you're not even pumping at that one applications are pumps conveyors and things when you get more into the industrial world or machines and OEM builders this is where you find telling closed non ventilators and what you'll notice about those if you actually looked at the frame sizes say one horsepower a which you would normally expect to see in a 50 60 frame
• 39:00 - 39:30 now would be in a 145 143 145 could even be 250 and what they're doing is they're compensating for their dough fan for cooling by having a larger surface area by increasing the signs of the load the frame so that's how they take and dissipate the heat from internal in the motor itself and by doing that that has a higher temperature rise internally and it also allows that motor to operate in
• 39:30 - 40:00 a much wider speed range sometimes upwards to a thousand to one so now you're down to one point eight rpms I'm being able to do that I see these and you know applications at large speed ranges conveyor systems and small extruders on a small plastic extruders again although this is me a constant torque application on these I see a lot of great distributor in New Jersey just
• 40:00 - 40:30 put a bunch of these in in an application you know these are in the hundreds of horsepowers nice opportunities we're there it's all enclosed blower cool weather again I think separately mounded motor and on the back that maintains a flood if you put a motor starter on it and allow that motor sculler just to run across the line no matter what the speed of the motor itself it has that cost of plug that gives you a thousand to one but also it makes it easier internally and
• 40:30 - 41:00 these types of motors where there was no fan to now now a simple encoder and with an encoder feedback that now gives you two thousand to one speed rings encoder feedback is it's probably going to be more for torque applications when you're starting to do paper machines or you're doing shared loads and coordinated drive systems it's not so much for the speed regulation but for the ability to
• 41:00 - 41:30 regulate the torque or the motor shaft when compared you know on a rewind or unwind stands in those types of environments but most times it's not needed for extruders a lot of times people put them on there but most times an extruder doesn't usually require it because AC drives too with their speed regulation and ability the program was called slip compensation you know if I have a simple rpm meter I
• 41:30 - 42:00 put on the motor and I can make some calculations and changes with internally within the VFD and I can get it dead not so much and then the driving the motor will maintain that so that's one nice thing about that oh here we go all right this is where you're getting into installation issues with motors there is a problem with monitors has a thing called capacitive parasitic capacitance
• 42:00 - 42:30 and if you talk to them at a repair shop so you talk to certain customers they know exactly what that is but if you'll notice see these little marks these little cut marks these bear you know people knew this but a bearing is one of the most precision design I mean products that are cubed has ever made think about what it does you know operating of thousands of rpms and maintaining integrity this what happens
• 42:30 - 43:00 it is is you get a very very very very quickly these will start notching and heat and so on so forth what causes it is what's called a parasitic capacitance that's a big areas words now you'll notice here these are symbols for capacitance and what will happen is between the rotor and the stator that will develop a capacitance and what a capacitance is is like a battery to
• 43:00 - 43:30 start storing energy so it'll start storing X amount of energy between that area and what happens is is anytime it's just like a capacitor any capacitor wants to discharge itself so it's one to go to ground and the only thing on the rotating member of that unit is the dielectric strength of the grease in the bearings so what
• 43:30 - 44:00 happens is that times the grease begins to get thin out of course and as it heats up it becomes even thinner and what will happen is a little arc will either hit this Barre where these batteries will discharge their current once they reach a particular level it will discharge and you'll do a little nick here it builds up again do another Nick here build up
• 44:00 - 44:30 again do another neck or it will actually out of the motor into gearboxes or machines and actually you're running out there which then that can cause problems in the bearings or what else in the additional loads that is driving so how do you solve this okay a couple different ways there's a lot of different people to do it different ways I ran motor repair shops about 20 years
• 44:30 - 45:00 ago and this had just come out about 20 years ago in the phenomenon was really in you know it discovered and you know this is an aegis but on other manufacturers have Shaffer ins so what we would do in the motor repair shop is we would now these Shaffer rings on women you know when the name of the motors either on a shaft and the driven equipment or on the backside and then we
• 45:00 - 45:30 would take in machine a Spicer ceramic spacer and make an insulation sleeve between the rotor and the arm armature and stator for the bearings so there was no path for the electricity to flow through so that you know with electricity a path of least resistance would be driven to the shaft ring which then would be grounded directly to the stator which then goes to ground because
• 45:30 - 46:00 you have to ground those motors that's kind of an expensive way of doing it to go that far I'm sure prices have come down some of those things have changed I have customers and distributors that handle cool-blue I've seen the demonstrations what they'll do with these is you would you know depending upon the size of the motor these common mode chokes what you would have is you
• 46:00 - 46:30 would wrap it or your motor lead through it and will neutralize a lot of these type of common mode noise and additional frequencies I'm not saying one way or another but I've heard people swear by them um so that's another inexpensive way to at least knock it down you can put these in a drive cabinet you don't have to do a lot of machining on the motor itself so that's another way of doing it they there's another one I'll talk about it there's another way of
• 46:30 - 47:00 that you can fix this as well a reflective way when I first found this business again 37 years ago I was a DC guy I was telling reliance electric large 500 horsepower Zahn extruders for Reynolds metals and so on and so forth so we didn't have issues and when deity's first came out I was working for rockwell at that time there was a coca-cola plant and I got a
• 47:00 - 47:30 phone call it was an OEM had shipped in equipment they had a I guess he was a four-day cabinet had there must have been 15 25 horsepower of the FDS and that four bay cabinet it was running all with the new line the filling line the transfer lines the packaging line conveyors and they had run all 20 of those motor leaves into one like 4 or 6
• 47:30 - 48:00 inch conduit tied to the system and of course the drives I got a phone call he says oh they're all tripping we had problems so when I set it up I immediately think about what was going on coming into a box and it been so bad that all the cables had melted inside that kind of do it and they had to actually cut the conduit act completely could reuse because it was so melted and intertwine and caused by the high voltage were reflected way and what
• 48:00 - 48:30 reflective wave is it was found that a long time ago when they started doing the transmission of medium voltage across miles and miles and miles and they determined that you threw a switch at a particular time and the length of time of the switch versus the amount of impedance into the cables its reflected back with the VFD when it's reflected back there is a formula to determine the critical length
• 48:30 - 49:00 so in the old days at the time it took to throw that switch on meeting the voltage transformer or a capacitor bank could take a minute or a second a full second or two seconds to throw that switch but would be f DS today using that same formula that switch is now in microseconds so you're talking about thousands of a second you know at six kilohertz six thousand times a second is
• 49:00 - 49:30 what's happening so when you look at that formula to determine the reflective wave it went from a hundred miles the fifteen feet if you use that formula so what happened started happening twenty years ago it was these types of thing where you see phase to phase or phase the stator because what would happen is it would generate voltage up to 1,800 to 2,000 volts and the old days and motors
• 49:30 - 50:00 were only insulated to 600 volts of course at that point you're exceeding the insulation and if they were cheaply made and they were dipped there would be air pockets inside these coils and what would happen is these higher voltages would exceed the insulation value with a cable and it would start breaking down the air pockets inside the dip and it would create a very corrosive product called ozone everybody knows those are
• 50:00 - 50:30 very corrosive and it breaks it down and then it would cause a short and then the drive of trip but what was finding out what was happening is the insulation then would cool off and then reseal you start to drive again oh he was driving drive people like me crazy I show up oh you're grabs a piece of crap buh-buh-buh-buh-buh look so the only way you actually could find the size if you took and put the motor in it in those days you would mag with a 500 volt
• 50:30 - 51:00 emetic leader but today with the VFDs and the insulation you only you'd have to make it almost at 1500 volt which is a destructive test yet be careful but that's the only way you could find out that that was a problem how you fix it you look here this gives you an actual sine wave at 500 feet no filter and no actual load on the cable itself and you'll see that you're down here in the 1400 volt 1500 volt range that's
• 51:00 - 51:30 demonstrating where the voltages now some of the simpler ways to do this is just to put a what's called a load reactor it's still a just a load or a line reactor on the output of the VFD and what you're doing is you're adding impedance and the impedance is like the old adage trying to suck you know through the garden hose that's only a half inch and you got a five inch line downstream you're not gonna get it out
• 51:30 - 52:00 so it will chop off and give you somewhat of a you know a sinusoidal waveform but the problem is is if you're going out beyond a hundred to 150 feet that phenomenon will real real though resurface when I was wrong the motor in Paris out in the drafts bachelors DuPont did a lot of work with us so I'm set up demonstration for them using line reactor actually using these inductors
• 52:00 - 52:30 they weren't cool blue in those days in a filter technically which I'll talk about in a second and you know I didn't have thousands of feet I only ran a maybe two or three hundred feet of cable on the floor and we demonstrated he tested and they were all basically about the same these cables just this inductive cable did a good job and then the line reactor did a good job as well but today you get out here into the old
• 52:30 - 53:00 gas industry or some of these other areas where you'll have longer leads or longer runs think submersible pumps some of those submersible pumps could be thousands of feet in the ground because it's submersible pump that's where the oil that's where the get asked what's where the water to be able to handle that that's when they developed what they call these output filters where an output filter is is you still have this in dock you'll notice there's a line reactor
• 53:00 - 53:30 there just like that but it also has capacitors these little symbols and what those capacitors are they are tuned to a particular voltage level you can actually tune the capacitor to turn on or to suck up a particular voltage so if it's above 460 volt the capacitor will then grab that voltage it will load you know it'll store it in that capacitor but since it's a capacitor okay it still
• 53:30 - 54:00 has to drain the ground that's what you're seeing here you have to be careful I don't know how many of you guys do industrial plant I need to do along when we made stuff in the US wasn't this old man wine again but I had run into things and you had to be aware of it HRG systems try and resistance for eons and what that is is normal I saw paper mills I've seen it in data centers is they cannot afford to be shut down so if
• 54:00 - 54:30 they had a ground fault you know even trip breakers upstream I had a 200-horsepower VFD sitting on a wall or next to of I think it was the Delta I forgot what the configuration is on the transformer and it just physically blew off the wall but what was happening is they have grounded that BFD and you do a grounding system my resistance ground you're actually grounding to a resistor back that gives the customer time they
• 54:30 - 55:00 monitored the the current gives the customer time to find the ground fault without shutting the plant down or shutting down all of the their plant there are processes so if you put something like this or just the EMC filter that's sitting inside the drive that is connected to a ground that can cause major issues so if you're in a plant you know be aware of a higher resistance ground if it's a critical facility with the filter you'll notice
• 55:00 - 55:30 at 500 feet it's now you know you're never going to be 460 it's never gonna be perfect but if 500 feet you'll notice it's a much cleaner sign we basically have taken about 600 volts off the top of it so it's much cleaner much better for them that were much better listening and terrible for the motor it's tough yeah if I'm sitting here and I'm telling you I'm going to generate
• 55:30 - 56:00 49 volts I walk into the facility look at the electrical guy and I look down and there's th hmm ehh w-what do you think is gonna happen to that Caden I've had fram oil filter plant called me and they had bring in the control wires and the output of the VFD in the same conduit and it was turning the PLC on which was turning the
• 56:00 - 56:30 paper machine on and off so you know you have to be very careful when you do your installations separate conduits grandma conduit back at the VFD if you're using tha tune it's a 600 volt rated no no I triple lead back long time ago wrote a paper again I used to do a lot of industrial and get cable tray so their table tray type of cable and what was
• 56:30 - 57:00 they found out is with the VFDs a normal engineer would specify approximately 50 years expect to have their cable last 50 years but when it was applied to a VFD it would cut the cable of life in less than half so they were having to replace the cable plus there were some induced currents between you know if it was a large horse power of the ft cable on the cable tray you could induce currents and
• 57:00 - 57:30 to say a smaller one banking or confusing the smaller DFT and causing it to trip thinking on an overload situation they've come and this is a Belden wire I'm just using him as example item you know I don't care they have a thousand volt braided there's some that's 2,000 bolt they'll have some that's even 600 volt but it's basically a shielded cable with higher insulation it has a ground and it's separated so
• 57:30 - 58:00 you can have that you could use this to run multiple leads and a single conduit so instead of having to run one conduit for every lead it's you know the prices have come down it's not exactly cheap but it's gotten to the point that you know this would be something I would recommend once you get into these situations on your installations so well gentlemen what time is it huh better now
• 58:00 - 58:30 I got playing pretty good Oh any questions I appreciate y'all stopping in um hopefully I recorded this I'm being it if it didn't but I apologize if it didn't hope you guys are safe and again we have you know we got our next one coming up oh what's the next one
• 58:30 - 59:00 April 30th which is probably next week so you guys have fun