Subscribe to our mailing list

+1(503) 655-5059
Home > Videos >Arc Flash the Easy Way - Part 3
Arc Flash the Easy Way - Part 3, Modeling and Initial System Analysis

The third installment of this series focuses on the use of the EasyPower Arc Flash Suite to construct the one-line model from the collected data and then proceeds to the initial steps required to calculated arc flash incident energies. Industry standards describing the use of the IEEE-1584 model are detailed and examples provided.

See the full transcript of the webinar below.

Download free demo

 Watch our most popular videos

EasyPower OnSite Intro

Utility Short Circuit & Arc Flash

Arc Flash Hazard Reduction

Arc Flash Hazard Reduction

Dynamic Stability Studies

 See all of our training videos

Full Transcript of the Video

Note: You can turn on captions in the video by selecting the small CC in the lower controls of the video (select English).

Jim Chastain: (Note: This transcript is a test of an automated transcribing system - the accuracy may not be 100%). Good morning everyone. Welcome to this third segment of our four-part presentation on how to implement an arc flash solution at your facility. My name is Jim Chastain, Iím with the applications group here at EasyPower. And our focus for this four-part series is how to offer options and ways that the facility owner can reduce the cost of compliance. We like to start with simple questions. Again we appreciate your feedback. It's not mandatory and there's no obligation whatsoever. But if you would please respond and provide us some feedback on these particular topics. First of all does your system include batteries or DC or hybrid components. We probably won't be touching on these much today but we are building additional webinars for future use and we like to kind of gauge what the demand is for some of these topics.

(00:01:08) Appreciate your participating. It looks like we've got most everybody uncloak included here and here's how things are split out surprisingly equal. And our second question is essentially what part of that analysis gives you the most aggravation. This is in terms of mitigation of the instant energy mitigation and same goes with this question is that we have basically a relatively broad brush approach for this part of the presentation and we are developing other webinars for specific parts of the system and specific application. So again your feedback is important. We appreciate your participating. Here's how folks have voted on the on the topic and for those views that selected other, please feel free to enter in the questions list suggestions for some of these other areas that we can focus on. We may not yet have time to get to all the questions on during the presentation but anything that is entered in that in the question box we will cover at least via email so the agenda for today for the most part will focus on the use of the easy power tools starting with a one-line diagram review.

(00:02:46) Then do some short circuit arc flash and coordination examples. The idea is to show illustrate what the results are required. The reports that are required for compliance monitoring and effectively make sure that you have a feel for the fact that you're on the right track that you're producing the right type of output based upon the input that you're putting into the tool. Now along that line we at the last session we threw up the slide which is essentially an estimate of the time required to do some of these steps. This is not to kind of limit anything.

(00:03:30) This is basically to give you an idea of how much you need to estimate and times of how dense your system is how complicated your system is and it's not push the button once and everything just kind of magically appears. So you know part of that is becoming aware of the nuances of what the study is producing and part of that is understanding how the tool works and what the complications your system may present in both of those categories.

(00:04:04) So, the de facto standard for arc flash calculations was developed by IEEE in 2002 or at least released in 2002. An application note titled IEEE 1584 was released in 2013 and there the results of that effort was a collection of four equations that produced the worst case arcing current and radiated energy and energy when given a minimum set of system parameters. The bottom line is that there are some tweaks if you will or some adjustments that are offered in these documents that may or may not apply to your study or your facility. And so it's worth being aware how the tool can implement these augmentations. The fact is the models themselves are recommended with some amount of limits and specifically the IEEE 1584 model is primarily recommended for voltages between 208 volts and 15000 volts. Three phase for both 50 and 60 hertz systems for voltage ranges between excuse me for current ranges between 700 amps to 106 thousand amps and then conductor air gaps between 13 millimeters and 152 millimeters.

(00:05:34) So obviously there are some systems or some portions of systems that lie outside of that range and they are they have been the basis for at least in the early days of this model for some criticism and so built in to easy power is actually the ability to select other models which again we're not going to touch on here. And if you have systems that out lie outside this limit I would encourage you to contact tech support and discuss what the alternatives are. One in fact and I've included a handout on this webinar is for highline utility work where there is a different model altogether than the three-phase model and easy power can accomodate those systems as well.

(00:06:22) So again utilizing the application code and contacting tech support when you have questions are available. So some of these tweaks include the recommendation to examine the system with and without motors in that and determine which is a worst case for your system. Also to look at any configurations of the system that may support operation for any period time such that there may be a need to inspect or maintain different parts of the electrical system during that configuration. This is a function that we regard as scenario manager and as you set up the specific configurations and labeling scenarios then the tool can automatically make those comparisons and and from that you can know what to label each of the busses for a worst case. Likewise 1584 recommends that you compare 85 percent arcing current with 100 percent arcing current and then use whichever produces the worst case incident energy.

(00:07:32) And again this is because due to the fact that the curves in the model are exponential and logarithmic based there are some times that the trip settings on the protective devices may produce may be long enough at 85 percent that it may produce higher incident energy. The suggestion in the requirement in 15 in NFPA 70E is to label system elements that need inspection during operation. Well as we've seen that doesn't mean those are the only elements that we need to collect data on and so it's important during data collection to be aware that there are some specific characteristics of the system and elements in the system that need to be recorded as part of the analysis process. One of which is the bus orientation whether there is vertical bus work or horizontal bus work in a panel or a bus way. What the working distance is for any particular procedure that needs to be.

(00:08:46) Part of the support of that particular element. Whether or not a main breaker in a panel can be included or should be excluded. If a particular piece of bus gear is in a enclosed box versus open air and then the recommendation by the IEEE model is to utilize momentary current which is the first half cycle and we'll see it in some cases that actually complicates the calculations so we'll discuss that a little bit. And then also the suggestion or the understanding that you need to consider the worst case utility current supply and X over R ratio. Because in spite of the appellation infinite source an infinite source for the utility numbers does not necessarily mean you'd be looking at the worst case. So any study once you've completed the one-line diagram will start with a short circuit steady and arc flash should be based upon the most recent up to date.

(00:09:56) Short Circuit Analysis and one-line diagram including these alternate system configurations. So what we're looking for here is basically the worst case current that any bus will see or experience in a worst case. Balance 3 phase fault and in addition to the amount of current. We also want to compare that against what the manufacturers have tested those elements to withstand and make sure that one the system will survive a worst case fault into the elements and the equipment will operate as the manufacturer has as tested and guaranteed. So then the study is used to develop and or recommend changes for our system which might include mitigation if we need to have personnel working on a piece of equipment. We want to take steps to make sure that they have the least exposure to instant energy.

(00:11:00) Some of the other functions are recommendations that could result from an arc flash study is an improvement in device coordination which is the ability to stage or sequence protective devices from the most remote element to the the primary supply or protective devices for the system. And the purpose there is to make sure if we have a remote fault that it doesn't drag down the whole system because it could be could have been cleared locally.

(00:11:36) Many of these are to the benefit of the facility and the operations above and beyond just the requirement for the arc flash compliance itself. Now obviously if we're this dependent on overcurrent devices it's important to have up to date information on the equipment itself which will be in the data sheets EasyPower includes the most recent information from manufacturers on each of the elements and is able to produce a time current characteristic curve which can be used for coordination. We'll talk about that separately. And then any time there's a relay or a sensing device that operates through a circuit breaker that has some opening time than that total time between sensing the fault and then breaking the the current the arcing current has to be part of the arc calculations. So obviously we want to document all the data that was used for the constructing the one-line diagram and the elements in the system analysis and part of that is to make sure as we're making changes or improvements down the road we understand what what the ramifications are and the change of equipment on the less study part of the documentation will be a report of the assessment type incident energy working distance the required arc flash protection boundary available fault current and trip time.

(00:13:22) All this again is informational. So that in a report such that people don't necessarily have to go through the one-line diagram every time to understand what any particular hazard is and then the bottom line is we want to include information that can be used by the operations team for maintenance and planning successful repair work and ongoing maintenance without exposing personnel to undue hazards.

(00:13:54) So these power arc flash suite to us consists of four separate modules a short circuit module which as I indicated was going to calculate the impedances and then the maximum current under four conditions for each bus. The arc flash module which will calculate the instant energy and allow us to make adjustments for any required changes and 1584 application power protector is used for the coordination function and then we also recommend an optional module SmartPDC which answers the question if this computer so smart why can't it do the coordination itself.

(00:14:35) And so we'll touch on that real briefly standard features and include that are included with the tool and elk and you'll see me implement these are. Or take advantage of these as we go through this smart breaker allows us to instantaneously change the configuration of the system during analysis and see what the results would be if any particular breaker or connecting device were open or closed. And the two recalculates both short circuit an incident energy smart duty automatically compares and compensates what a manufacturer's test results were for a protective device compared to what the environment is in the system. So if a manufacturer tested a breaker in a environment that had an X over R of some specific value because we plug that breaker into our system and that X over our environment that that breaker now sees is different. The test condition or the test environment needs to be compensated so that we're looking at how the breaker will perform in our system.

(00:15:43) You're going to see me invoke the use of the library multiple times and there's some other features that I'm not going to spend too much time on including manipulation of the one-line and features that we call that are part of our easy controls feature series that become very useful and we will again touch our minds as we go through this. Now as sweet as we fought the buses once were in short circuit focus we can't fault a single bus. All the buses in the system or some subset just by indicating which part of the system we want to fault each protective device displays the required arc boundary let through energy and the user's working distance all of which are part of the seta and then a requisite report is the arc flash spreadsheet we refer to it as the arc flash hazard spreadsheet and includes all of the data that's utilized in calculating instant energy in arc flash boundary.

(00:16:54) So where we left off last week is we've completed the data collection we've constructed the one-line diagram. And as we did so we entered the data that has been collected we do a very simplified one-line diagram of the typical elements in our system just to make sure we understood the mechanics of the tool. So now we've gone back with that knowledge collect to the rest of the data built up the one-lined diagram and our first step now is going to be calculating short circuit studies so we've completed the data collection. We've drawn a one-line diagram entered all the data and we want to see now that we can present or get out of the tool short circuit arc flash and coordination, so let's jump into EasyPower and see how that works.

(00:17:50) All right. Is a one-line drive diagram of a typical radial system and we can see that we have we don't have any missing data. Again if we had something that wasn't populated at a minimum for short circuit analysis the tool will give us an error report but as long as we go to short circuit focus and receive no errors then the tool thinks at least we're on the right track. So as I meant short circuit focus we're looking at the first thing we want to do is look at that momentary current. So we select half cycle current up here at the top row and we want to select a three phase balance fault. The tool has the capability of displaying other or invoking other types of faults but in terms of arc flash as I mentioned earlier the three phases model the IEEE 1584 is the only one that's been developed for arc flash.

(00:18:49) And it utilizes three face falls. So at this point we're ready to fought the buses. I haven't selected any specific bus. So my fault all the buses and as we do that we see nice numbers and pretty colors and for the most part we're looking at this point just to see if there's anything untoward or out of order or the wrong order of magnitude. The tool has the ability to display all three phases. Again it's balanced it's a balance fault. So they're all going to be the same. So for simplicity's sake we're just displaying a face. Now what this means if I have a fault three face fault here on the main bus we'll see from each face coming from the utility.

(00:19:42) A current of twenty thousand six hundred twenty five amps will also see a motor contribution because we're including Motors in this system that totals up. It looks like somewhere near three headed amps from the load down stream. So the total stress on this bus may amount to as much as almost 21000 amps. So that's what this bus needs to be rated at. So if we don't have any we don't see anything obvious as far as the bolt of fault current. The next thing we want to do is to check out equipment duty to do that. There's a little icon here on the second row if I invoke equipment duty I see a red fuse here and if I kind of scroll up I see another red shoes up here.

(00:20:33) This one has a minus 8 percent and this doesn't have anything well one of the other reports we're going to produce ultimately is going to be this the equipment duty reports So let's go look at that now. Short Circuit reports icon at the top easy Power calls spreadsheets text output. Let's create equipment duty report expand it and include all devices. So as we apply that and then go back to the one-line under our list of windows now appears equipment duty report and what this shows this is for the FS one the manufacturer the type that the fact that the datasheet indicates the test standard the manufacturer used and it's rated for 60000 amps and we're showing that it's going to be exposed to 55000 amps which means we got about eight point three percent headroom on that particular device.

(00:21:36) Now the reason it's it's flagged is we've set our limit or our alert limited at 10 percent within 10 percent of the limit and so on scroll down the rest of the way and I don't see anything about the other fuse so that presents us with a couple couple of decision points. First of all if I go into my short circuit options and I look at my controlled tab I can see right here on the equipment duty threshold that I've set this for minus 10 percent or within 10 percent of the of being non-compliant. If we were to if I were to say Well I'd like to set this up to 20 percent if I want to look at anything within 20 percent of the rating. Is to a minus 20 percent and apply this we see that now at this point we have several other devices that don't necessarily fit that are not necessarily out of compliance but they're within my 20 percent limit.

(00:22:42) So for now I'll just leave this at minus 10 percent. But that explains why the the red indication on FS 1, still bothered by a lack of data on FS 2. If we were to look at the data base because it didn't show up on our our report our equipment duty report. So let's go back to database and go and see where changes is because we can and we look at the get this fuse Okay we see we set up the part number for the fuse the size for the fuse when we go to short circuit we want to click the Calculate button and see numbers change here because that indicates the manufacturer has the tool is located the manufacturer's datasheet.

(00:23:37) And this using the test environment and the interrupt rating that the manufacturer has recommended. So obviously we haven't completed this step before I do that. Let's just go ahead and do it now. I'm gonna click calculate, sure enough my tech my test environment changed and my interrupting rating changed and so that was the problem that this wasn't showing up on the on the report but it was still flagged red. So it makes one wonder do I have any other elements in the system that I don't have accurate data or at least a minimum amount of data to be able to be recorded and equipment duty the utility that we use an easy power is under file database browser. As I invoke that it brings up this nifty little utility that shows me all the buses and all the elements in the system.

(00:24:36) And I want to look at my equipments by grouping so if I look at the buses I can see that on several of these buses I don't have the rating now this is normally something that will be on the nameplate for the panel or bus work and the manufacturer or the panel builder will indicate what the bus rating is and what the bracing is. Interrupt rating. And so clearly either I didn't collect the data or I didn't enter it. And so I need to go back and fix that if I go down and look at my fuses switched fuses so I can see this is where I could have checked earlier and I would have found that my interrupt rating and my X over R values were not properly recorded because I hadn't invoked the Calculate button so the enter the database browser can be very useful in verifying whether or not my my data is completely entered right.

(00:25:39) So take a step back go to short circuit Focus look at our short circuit current again half cycle so it's momentary look at our insane energy. Now this but this fuse is no longer an issue. And and this one still has an X or has it exceeded or gotten any better than my 10 percent current limit. So I'm I feel pretty good on the equipment duty to go back to our short circuit reports. Now what we want to look at or create a report for is a high voltage and low voltage momentary reports that includes the duty. And we can we can designate simplified medium or detail form that we're going to cover more of this as we get into next week.

00:26:35) But at this point I want to make sure that the information's being dealt with and presented properly. And as I go in and look at my list of windows I low voltage momentary report should look something like this and we'll talk about why this information is useful for other purposes. Next week OK. So at this point we're fairly satisfied that we're producing the reports that we wanted. We don't see anything abnormal about my short circuit report. Now normally we go through that coordinations step at this point but I'm going to handle that separately because most of this are most of these are moulded case circuit breakers. If we look at our database that it and consequently they're not going to allow us to do any adjustments. So let's assume I've handled that prospect we've dealt with coordination or we're not requested to do coordination as far as company policy because we feel that that's all under control.

(00:27:45) In any case, couple of things I wanted to touch on just because we're here it may be that that we want to look at and include the short circuit and arc flash calculations as part of my panel schedule is the power includes utilities that allow us to take and isolate individual elements of the system if we. Rather than look at the entire one-line it may be useful too. Like I say isolate on specific elements so we can either emphasize or report on them or keep track of it so minute. Take this particular panel and it's feeding in its bus work take off this part of it and by going to easy controls drawing and clicking on this new drawing insert it carries that part of the design onto a single sheet.

(00:28:42) And I'm going to call this panel. Looks like it's one a bus to a panel one underscore a now part of my part of my report I may want to include the schedule so if I highlight the panel and right click I can insert to schedule and it looks something like this. Now we can see the standard default schedule presents all the loads the totalizes each of the phases and gives me information that I consider pretty normal but because I'm doing in our flesh study I developed a custom schedule so that I can show that information on my panel schedule. So to invoke that I'm going to go back. My main one-line and I want to go to the file properties and under the Properties tab we can assign a project name the school and do that.

(00:29:52) I can do other kind of comments that's useful but what I'm really looking to change is a panel schedule. Right now we're using the default that comes with the tool. What I want to do is stipulate this customized version I've created in XML and I'm going to call it Jim's panel schedule and as I do that it says OK this is going to change everything. Are you sure that's what you want. Bravely tell it, yes it is. And as we go back to I know I can put the panel schedule here on the main one-line if I wanted to just as we did before. Just go up to right click insert schedule and it'll give me the ability to put the panel's schedule on the one-line rather than do that I'm going to go back to my my sheet my answer sheet and you can see now I have an extra row in here that includes a symmetrical short circuit current, arc flash boundary, working distance, and the incident energy.

(00:30:55) All of which is is useful. And as we make changes and go through the analysis it will be updated. If we make changes on the panel schedule Okay so I digress let's go back to a short circuit focus cycle current three phase fault fault all the buses the window reduces in size because it's telling us that all the reports are down here at the bottom of the screen.

(00:31:27) And as we saw before they're also listed under the list of windows. What I want to do at this point is utilize you arrange for arc flash icon going expand our main window and arrange for arc flash which shows all the calculations and parameters that are going into the calculations for each of the buses. If we wanted to isolate a focus on a specific one we DoubleClick that particular bus. And so it shows us the voltage the upstream trip device and you can see in this case the upstream trip device is actually the one upstream from the panel and that's because we've set other options short circuit options. Arc flash hazard tab these are the control settings that I was referring to earlier that are reflected in the IEEE 1584 one which is the application note. So one of the settings and these are global settings so one of the settings was whether we include or exclude the main. So we've included we've set this up to be exclude main the tool lets say OK we can include, exclude, or go and show both.

(00:32:47) So as we apply that we're going to go to our we want to go to our incident energy so, invoke arc flash icon here which is the burning man symbol double click on the bus and we see two numbers here. When we go back and open up my short circuit options and leave it here so we can work on it.

(00:33:17) The lower number will be the calculations. If we use the main breaker the higher number if we use the upstream we exclude the main breaker. And again this is this is has nothing to do with reliability or the expectation that this breaker will fail. It has more to do with the fact that there is or is not a barrier of arc flash barrier between the incoming conductors to this main breaker and somebody working on this panel. So if the spread is too great and we want to be able to utilize this device one solution may be either to change the breaker into a situation where the there is a barrier between the incoming conductors or move an intermediate protective device outside of the panel so it is not affected by that. So it doesn't allow us to worry about the use of this main breaker.

(00:34:20) So that's the function of this worst case arc flash hazard selection guide so for now we're going to exclude the main breaker. Now all of these settings can be overridden on a local basis. Again they're global settings I mentioned earlier that I triply recommends 100 percent arcing current and 85 percent arcing current be compared, and then whichever produces the worst case incident energy be used and the tool does that force automatically we see down here on the arc flash hazard hazard spreadsheet where there's a dark type under fault current trip time and it's an energy 100 percent arcing current was used for those calculations. If the type is magenta as we see here on the main that means 85 percent arcing current and and that's how you can tell that comparisons don't automatically These are adjustable but by default the recommendation is to use a 185 and 85 percent.

(00:35:32) Again, the recommendation by IEEE to use momentary current for calculations. There are times when we may want to consider something else if we have the fault currents that are very low or and situations where we have multiple contributions to this bus and we have Webinars on this topic so we can we can talk about this in more depth. There there may be an opportunity to use the integrated method which uses momentary current for the first half cycle adds to it. Interrupting current for the next five to eight cycles and then for anything beyond 8 cycles it adds up the energy produced by the long term short circuit current and where the result is as a more accurate instant energy because just using momentary for the full fault time can be very conservative. All right.

(00:36:28) So we've got working distance and inches can be in any particular units we're choosing working distances from this chart down here to apply to enclosed bus work or to open air for the range. In this case from 300 to 750 volts we are established an energy threshold of 4 calories. Basically we're saying for anyone in the plant any qualified workers their normal work gear their normal work dress will provide for calorie protection. What we're doing is calculating an incident energy at that specific working distances. In this case 18 24 and 36 and the tool will tell us what the what the energy is at each. And then we have to make a decision whether or not the four calories are going to be adequate. So it'll flag any area that's not that exceeds four calories. If we want to say Well, no I've got a process here that needs or requires someone to be in a 10 inch area working distance of 10 inches.

(00:37:42) I would I could just enter that in my matrix and apply it. And what we see down here on the arc flash hazard spreadsheet if we expand this little plus sign it'll show us both the default working distances 18 24 and 36 as well as the the 10 that we requested. And so that gives us the ability to say okay in this particular bus if if we're need to work on something at 10 inches the incident energy three calories. If our normal dress is four calories and then we should be covered as far as the requirements for hot work on that bus. Well the tool is presenting up here is the arc flash boundary which we learned earlier in this series is the point where the incident energy is at 1.2 calories per square centimeter.

(00:38:43) And if by default working distances at 18 inches then we expect the 1.3 calories to be very close to what the arc flash boundary is. Right. Other elements of the short circuit options arc Flash hazard tab in just to kind of take it one step further. If we go to the Advanced tab we can we can control whether or not there's going to be a PPE level as part of the display for labels and not. Again we'll talk about this more in-depth next week. And and this would be the area that we would apply and utilize open-air buses which is a single air, to a single phase to ground calculations.

(00:39:35) All right so for the most part this is the requisite analysis we're looking at basically. Does this make sense once we fault a single bus multiple buses all the buses then we're able to verify which areas specifically we may want to focus on for mitigation and because we need to do work there and for some reason we're not happy with the answer and energy at the working distance required for those job procedures. All right so it take a step back from this we'll go into reports in more depth. Talk a little bit more about mitigation next week and arc flash labels. What I like to do now is talk about coordination and again this requires essentially the use of the coordination module which we refer to as our protector.

(00:40:53) We're also going to touch on SmartPDC. So this particular example is a little bit more complex in that we have several layers just what protective devices are going to go in to short circuit into a coordination. Having already done kind of a short circuit approach with the tool when it falls a single bus downstream looking at the current and what we see is the branch current for this particular fault and because we set the remote current and voltage indication we're seeing also the contribution of each of the remote busses to that fault. So if MCC 2B has a fault we will actually see as much as 130 amps contributed to that fault from this remote MCC. What this is also showing is that this bus will still be at point 95 per unit which means these motors could be running somewhat degraded but they could be running even while this bus is thought that in it's it's bolted just fall into at least 50 percent.

(00:42:13) Now. While I'm here we're looking at incident energy during the. Excuse me that short circuit current during the first half cycle the tool allows me to utilize this sequence of events icon. And as I do that it shows or indicates a chronological order for all the protective devices upstream from where the fault is located so in this case if MCC 2B false, this breaker will trip in 190 milliseconds. This this breaker will trip in 35 seconds. This fuse will trip in 32 seconds and this relay will trip and 600 excuse me 300 milliseconds and their flagged red because they are out of order. You might say Jim that's good information, can you give it to me in a report. By selecting the PDC options, right hand column, create a sequence of events report and then go back down and fault that bus again.

(00:43:18) That's going to show me that same information in tabular form. Now if I go back to my one-line I don't select any bus and I fault all the buses that means it's calculating each bus and each upstream trip device order. But there's too much information to show on the one-line. But fortunately on the sequence of events now I can show every bus and the upstream pecking order of protective devices tripping. And I noticed here in every in every case of the downstream buses the relay is tripping out of order and sometimes with or without the inclusion of the upstream fuse. So we do have some amount of coordination issues that we need to deal with in this particular system. So the next step in the process of coordination involves picking a largest downstream load and then picking or selecting the next two or three upstream protective devices and then looking at the elements on a temperature time current characteristic curve. Well just this minimize the time we spend here I'm going to do that by less clicking and selecting the motor everything up to the relay and I could do this on either leg.

(00:44:52) But the idea is to is to coordinate ultimately all of it. So I'm gonna plot the TCC. Now when I say coordinate all of it there's there's always a conflict between coordination and mitigation. And so there has to be some decision made as to whether or not we have an adequate system set up both for human protection and system reliability which becomes a more complicated discussion. So as I'm rearranging these labels I see that this then blue line to the left is the motor starting curve and indicates that during a normal start. The current drawn by the motor can be off to the left for any period of time that's indicated on the left hand axis. And as long as it doesn't exceed the curve that means it's considered the manufacturer considers that a normal start the short stubby line is the thermal damage curve and these reflect the information that we entered when we set up the motor in our one-line diagram on the TCC page we indicated a locked-rotor multipliers of six and the inrush and stall times, which is used to plot these curves.

(00:46:20) If we let's say by company policy wanted to use a locked-rotor multiplier of 12 if we apply that you can see how it changes those curves and make potentially makes coordination more difficult. So for now I want to take the easy way out, leave it at a 6x Now I can I can display that on a temporary basis either by opening up the motor icon on the one-line or the motor plot on the TCC. So the functions or the dial settings on the trip devices are reflected if I hover over the effect in each of the labels it shows the current dial settings for each of the protection devices Here's the relay.

(00:47:06) Here's a first down stream breaker and here's the upstream breaker and here's the fuse which is not adjustable. So the challenge for any engineer is to be able to left click and drag and the tool shows me what adjustments I'm changing as I do this movement and ultimately get the curves for the breaker. Is this set up to the right hand side of the motor starting curve and to the left hand side of the thermal damage curve and. And it takes a fair amount of patience and it's somewhat tedious. But as you notice well that the tool will not allow me to just willy nilly place these anywhere. They can only be set up for the datasheet reflects a dial setting that's available on that particular device.

(00:48:05) Then the next upstream device which would be the fuse is not going to be adjustable. So my BL2A would be something that I'd want to drag over and set up and to the right from the downstream breaker and then ultimately I'd want my related trip last which presents the conflict between mitigation and coordination for coordination. I need to slow the relay down to be able to allow these other trip devices to do their thing for protection or mitigation. I probably want my fastest tripping devices tripping any time there's a fault so there's always that conflict between the two methodologies. Now we can see from this that if we have a fault downstream of this bus or double click on it we see our parking current. We also see tick marks and the curves are clipped at the maximum current that will be generated through any of these breakers.

(00:49:12) So through breaker 2A the maximum current 41 thousand, which is going to be this puppy right here on the end and the to say so this is the bolted fault current which is greater than the then current that's indicated on the bus in part because there's additional current coming from the motor. Now, so again the question is if this computer is so smart why can't it do this coordination thing itself. It may be that I'm not very good or I'm not very careful for some reason I've missed the boat and I leave my system set up like this which may not be acceptable either in terms of coordination or incident energy. Again I can fault this bus show the archingcurrent fault current and show the incident energy and it's more than likely still controlled by the relay if I can right click and insert the arcing current.

(00:50:23) Sure enough there is a arcing current and according to this the relay is going to trip before the breaker trips. So rather than risk embarrassment or creating an unsafe condition or in this case a condition that may not even allow motors to start regularly or repeatedly I'm going to invoke SmartPDC, which allows the computer to give me some recommendations of where I should be starting with these set points. So it's calculated the currents through each of the devices. It's made some recommended settings and redrawn the one-line or the TCC plots such that we have the downstream breaker now clear of the motor damage curve here and clear of the motor starting curve to the left its position the next upstream device which is BL2A, the magenta one, up and to the right and it's pulled the relay back up.

(00:51:34) So it's clear now of the downstream breaker that if and it's also calculating incident energy which may or may not be better but at least it's going to be based up on the settings of BL2A. And how do I know that is if I right click on BL2A and insert the arcing current it shows me that at 100 percent arcing current this bill today will clear in this amount of time. And so that's the the energy is going to be calculated for this time. Where this current level crosses over the upper boundary of that to breaker now it may be useful to say well how much clearance do I have between the breakers and an arcing fault. I can select a downstream breaker down control select the upstream create the difference and then center it over my arcing current, might want to do the same thing between the upstream breaker and the relay and so with a fair amount of confidence if I center this over my arcing current, I can say for an arcing fault I have 300 millisecond separation or clearance between the time the downstream break will clear and the upstream breaker starts to pick up. And 1.85 seconds between the time this breaker has a chance to clear and the relay does its thing, now more valuable than than just doing the fancy drawing and the re reshuffle of the plots is the fact that it will produce an auto co-ordination report. Now for me which shows ok for this particular device these are the elements that I'm trying to coordinate with.

(00:53:28) These are the old settings. These are the new settings and these are the comments that an engineer should be paying attention to because we have in this case one of the breakers is set to maximum setting which may not necessarily be selective with another breaker. And if we kind of scroll through this the net result is the engineer can now managed by exception rather than go through the tedium of a large number of resetting all the protective devices. In this case it's saying OK the fuse is unable to protect the lowest point of the transformer curve from damage which may have been a design a design condition. But at least we're making a note of it. So then from my ultimate report I do want to save for the project. I want to save this plot indicating that I've made I've considered all the ramifications of these particular settings.

(00:54:32) I may want to make some adjustments myself and say rearrange this particular curve with the risk of the possibility of having some kind of conflict here between the starting curve and a moat and the breaker response. But let's say I was willing to risk it for the extra room I have here from our thermal damage again this these are the kind of considerations an engineer would want to take into account. So I saved the plot I saved the report. And when all is said and done we ultimately want to save it at this point which I'm not going to do. We ultimately want to print out a report and then make recommended adjustments for the systems trip settings and either make those adjustments ourselves or request the maintenance manager to make the changes as a result of the study.

(00:55:50) OK so at this point, I'm gonna back out of PowerProtector. At this point we've looked at short circuit focus we've looked at the arc flash module and calculations we've looked at the co-ordination module which is called PowerProtector and we've looked at SmartPDC. At this point we are able to produce and have verified we can produce short circuit currents and X-server over our calculations equipment duty reports arc flash incident energy calculations from which next week we're going to generate labels and we've shown how to do manual coordination, how the tool will give us the ability to examine the adequacy of our protective device set up. And if we're so inclined we have the ability to have coordination recommendations made automatically by a SmartPDC.

(00:56:55) So I'm a happy camper. Let's go and pick up the rest of our slide show so what we're going to pick up next week then we're be the reports and the labels. And then how to interpret some of the ramifications as far as mitigation and recommendations to the to the facility. Appreciate your attendance today.

(00:57:37) We do have the ability if you're a tool owner and you'd like to have someone by all means you have access to tech support via e-mail and phones. But if you're at the point of doing your first study and you'd like to have your files reviewed in an engineering review we can quote time and materials and give you the the peace of mind that an expert reviewed your work and as basically helped to verify the accuracy of your calculations. And invite you to check out Again we have next week's webinar scheduled there. We also offer for any new tool users a Power Start for free, which is a one hour GoToMeeting session with new tool owners for tool orientation and specifically addressing any issues that your system may present. Also available to anyone with a tool maintenance agreement current who has employees come on board since the tool was first purchased and that may need a new tool orientation.

(00:58:57) I've made available arc flash reference material as a hand out. There's others on the web site and you can check out regional training which will be in Cincinnati this year. We also have a new system on power systems analysis a new training three day training class which will be offered here in Portland later this month. Really will not be focusing on arc flash whatsoever it's more more in-depth analysis of a standard power system design and maintenance issues. Very very useful for someone who maybe hasn't been in that capacity for a long period of time or has moved in from say control systems engineering position and now has more responsibility to look at the holistic power system itself. I encourage you to download the flyer.

(01:00:04) It's going to be like I say the end of October and I think it'll be very informative for anybody and a facilities engineering position. Like I say we probably don't have time to cover questions today. Thank you all for attending and any questions submitted will be responded to in emails. Have a good day.