I know this is a bit out of the rhelm of the normal control type topic, but it seems that I have been awarded the new title of "Arc Flash Guru Guy" for our facility. I was wondering if anyone else out there has been awarded this title, and if so, have they found any good modeling and analysis software? Also, has anyone found any good websites regarding the arc flash topic? Any information on this subject would be fantastic.

Thanks in advance,
Beuwolf

I have just recently been apointed that position. Reading the NFPA 70E is a must to start with.

Have you got it yet?

I am waiting for my copy to come thru the mail. I am also investigating different modeling software too, just not sure what to look for besides the typical price justification.

Also has anyone had any formal arc flash training that they would be willing to recommend?

Also there is a some NFPA 70E Blue Book that might explain things a little better. I'm going to get one this weekend. Will let you know if it helps

Depending on the complexity of your power distribution system, you may not need modeling software. The calculations are not that hard. I'm writing some code to do it. Don't know how much modeling software is but you may be able to do it with your own software (even excel could make the calculations) or do it on paper. Talked to another guy and he said if you do it yourself, just document how you did it and OSHA will be fine with it.

Found this

http://www.bussmann.com/apen/arcflash/

May be worth a look, once you've registered.

We have SKM Systems's ArcCalc software. It has specific device trip curves for many brands of protective devices, and documents everything including the boundry, incident energy and PPE level required. It even can print 70E compliant labels to put on your panels.

In the past we had just used the 4ft default for 50-600V as allowed for panels where you haven't done the calculation, but for most of the panels, 4ft was absurd once you calculated it.

How did you calculate you energy for PPE? Or did you just go by the chart in the book. Both the 48" and chart are definately absurd after viewing the results of the calculations.

Did you look at changing you fuse types to reduce you Arc Flash? The type of fuse can really reduce it. I'm debating whether it would be cost effective or not to reduce the PPE that is necessary

"in lieu of the flash hazard analysis of 130.3(A), Table 130.7©(9)(a) shall be used to determine the hazard/risk category for a task"

For instance, if you were voltage testing 480V, and you obviously are standing within 48", so you have to have PPE Level 2*

Did you just impement the Arc Flash labeling of the panels or are employees required to use the proper PPE?

We are wondering how much resistance we will get from having to wear the PPE. Do you have any suggestions or are some PPEs for Arc Flash more comfortable than others?

Was the pun intended? :)

The employees are required. If they were caught without it, they woulld be written up. It's just the rules. We provide them with the FR pants and shirts. There is no excuse. Usually during the hot summer months, they just wear the pants and have the shirt ready in case they need to perform a task that requires it.

They go through Electrical Safety training so they understand it's an OSHA requirement.

So did most of your panels require class 2 protection?

One other thing I haven't found in the book is when we are working above 6' from the ground, we are also required to wear fall protection. They are not allowed to wear rings but our harnesses have metal buckles. How are we suppose to protect them from the metal buckles on the harness?

We have fall protection requirements here too. We had to select a harness that didn't flash or melt and affect the FR rating. I don't remember ever discussing the metal ring. But I think at the end of the day, we decided that here people probally wouldn't be working around exposed live conductors in a harness anyway.

It seems to me you can read it two ways. You could say that it is a conductive article being worn, and not allow it period. Or a conductive material being handled:

130.6(E) "Conductive materials, tools, and equipment that are in contact with any part of an employee's body shall be handled in a matter that prevents accidental contact with live parts..."

It also says that "means shall be employed to ensure that conductive materials approach exposed live parts no closer than that permitted by (restricted approach boundry)"

So for 50 to 300V, it would be avoiding contact. For 301-750V it would mean ensuring it was 1ft away from any exposed part. What 'means to ensure' would be I do not know.

It's a very good question.

I also have done the arc flash for my plant.

I started by hiring a PE to do a full Short circuit, coordination, and arc flash study of the plant distribution down to the panelboard and distribution bus level. The short circuit study uncovered many instances of circuit breakers not rated high enough. I just finished correcting all of that with replacements and series ratings. The PE used SKM software. The IEEE calculation is supposed to be better than the NFPA calculation but I am not sure why. The full SKM software to do the short circuit, etc. is about $10,000 for a decent sized facility. The PE I hired was a little cheaper.


Then I bought the SKM Arc Calc program for $995. And I am now calculating arc flash down to each individual machine's disconnect, based on the short circuit values from the study.


The bussmann short circuit guides are great for calculating short circuit currents, they match the SKM software pretty well. Don't forget the 4X FLA Motor Load contribution.

For PPE we have been going by the chart in the NFPA 70E, until now. We changed alot of fuses feeding our bus duct distribution system and we now have almost all Class 0 or 1 throughout the entire plant. We use the bussmann low peak fuses, class RK1.

If you have a small plant you can calculate everything just fine. If you have a large plant, especially an old plant with alot of revisions over the years, I reccommend hiring a PE to get you started. This whole issue is over safety and I would think when dealing with OSHA a PE's stamp is alot more convincing than a staff engineer's or tech's work. Especially if they visit after an accident.

The PPE our guys wear is all Class 2, or if they wear long sleeves there own clothes are Class 0. They have a couple of Class 4 suits for the high voltage rooms, but there may be only one place where they are required, since the study was done. We have one spot on out 480V substations where the incident energy is over Class 4. So basically you can't work on the substation without completely deenergizing it. You wouldn't want to work on it hot anyway.




We are still labeling everything. The label is necessary to tell the employees what level of PPE is required.

You will get alot of resistance from all employees. I even gave it some resistance. Our PPE requirement came from our safety department. I got involved with the calculations later on.

Our PPE kickoff started with two days of electrical hazard training. It was all those videos of guys dying of electrical shock and stuff. It was taught by a guy who worked the Utility business his whole life, so no one could win an argument with him. It set the tone very well. I believe the training on how and when to use PPE is required by OSHA as well.

Lot of cranes here so have to have harnesses on during voltage testing. I will try to make some calls to figure out how this is supposed to be approached. Voltage rated harnesses perhaps?



Just finished writing software to calculate the values using the IEEE method. Hadn't thought about hiring a outside guy who was experienced in this to introduce the arc flash training. This could give it much more weight than than our safety director doing the class.



Are there any faster acting circuit breakers that could replace some of our existing circuit breakers? The fault clearing times on these are killing us. With the fuses we are at class 1 on most of our machines.

One of the guys just asked me if prescription safety glasses would meet arc flash specs since they have metal frames that could absorb heat. Any ideas?

In our last training session we were informed that plastic frames are now required for electrical work. I don't know what code book calls for it though, probably OSHA. The glasses are supposed to meet an ANSI spec., i believe it is Z87.1 I have a sefety manager that handles all of that. So i'm not completely familiar with all the glasses requirements.

A little off-topic, but there's a couple great video clips of some serious arcing at

[url="http://205.243.100.155/frames/longarc.htm"]
[/url]http://205.243.100.155/frames/longarc.htm


see:
- 230 kV (1.2 MB mpeg) and 115 kV image of three-phase air break switches opening "hot"


- 500 kV switch creates a 100+ foot arc when one phase opens "hot" (1.5 MB mpeg)


- Arcing fault causes a substation transformer to explode (5.1 MB mpeg)

New - Another arcing fault in a substation - HV fuse fails to open properly (10 MB avi)

Dan

This 70E thing has almost turned into a joke. I work in the Auto manufacturing industry (UAW), and now when I open a panel to look at the status of a PLC, I must wear my "face shield (special UL appr.), HV gloves (rubber/ under leather), special clothing and no synthetics'. The company had to pay out big bucks for a survey on 'calory' exposure, training, etc etc. Now, per law, when your working with a 24 volt signal and a 22 ga. wire in a enclosure that has 480v in it......you gotta wear all that. Unless you lock out/ tag out. So I really love these guys out there making all the rules for us. If your a real sparky, you know the one hand rule, dont touch the hot wire, and dont carry on a conversation when you got your hand in the box. Oh, did I mention how comforably WARM these Bullwark shirt and pants are. Cant wait for summer.

It is extreme sometimes. We used to cheat all the time, until we got caught and some of the electricians were written up. Now we try to design for it, and alot of our panels are at Class 0 or 1, so the need for the heavy gear is minimized to almost never now. The fact most of our equipment is fed from fuses saved us in the long run.

Unfortunately, sometimes the only way people will take it seriously is to have an accident happen. That is what pushed the whole thing at my place. Fortunately the guy recovered almost all the way.

Ok, got most of my calculations done and have designed my labels, now I am a little confused about where to put them. Do they need to go on the front of the panel or can they go on the side of the panel? Most of our labels are on the side of the panel. The reason I do not really want them on the front of the panel is it is subject to more abuse and dirt than the side of the panel.

One of our welder technicins asked another question. When working on a wire feeder (which is less than 50 volts), do you need arc flash protection since it is feed from a 480 Volt power unit. My initial answer is no since the power unit is pretty much the same as a transformer but was wondering what others thought

My take on it is:

If you work in a hot panel with a voltage >50 volts then you need the arc flash stuff, unless the >50 volts stuff is segragated and covered from the under 50 volts stuff.

Most of our panels have a main CB, 480V. If the three wires at the top of the CB are hot but the main is off, the panel is still considered hot. Unless the CB is covered. Which was tuff for all of else to swallow initially. Now we mount disconnects on the outside of the panel, and lock that out.

Now how important is it to "REDO" all the calculations if motors are added or transformers changed and all that good stuff? In some plants I have been in, this could be almost impossible since machinery is moved in and out of production areas all the time. Would calculations just be done on the buss drops, or per machine? We typically move some kind of large current type device here at least once a week if not more. According to what I have read, that would require a new set of calculations, and it would mean a full time job for some one. Or am I making a mountain out of a mole hill.

I think you summed it up the best here.


Just use your best judgement when you move something.

How about the label position. I can find nothing saying the label has to be on the front of the panel. Does anyone see any problems with putting the label on the side of the panel?

I've never seen anything that said that you couldn't. If you are going to train everyone to look on the side then that sounds reasonable to me.

Our disconnects are on the side of the panels so it may make more sense anyway. I'm thinking about putting them right below the disconnect

You guys getting tired of all these questions yet?

Several points in our system are a category 0 or a low category 1. Our safety director wants to make the minimum flash protection category 2. Does anyone see a problem with increasing the category requirements?

The reason he wants to do this is to discourage working on panels live.

What a safety guy he is!! [That's an insult]

I would label the panels with what they truly are.

At my facility we only provide PPE for Cat. 2 & 4. because of cost. So if its cat.1 then you have to wear the Cat. 2. If its Cat.0 and you wore short sleeves that day, then you wear the Cat. 2.

Cost is a much better reason than discouraging people. Its discouraging enough without his help. Technically you need an energized work permit to work on a panel live. If thats not discouraging enough then I don't know what is. We fill these out once per year for troubleshooting purposes, right after the refresher training.


No, in a sick sort of way I'm glad others have the same issues I have. As it is I feel like our business is the only one in the county doing this stuff.

Didn't think about how much of a pain the work permits are going to be. That will be discouragement enough. Thanks for all of your help. I'm sure I will have more questions

Ok, couple more questions.

1. Is a crane with an exposed feedrail considered a movable or fixed conductor when when figuring the Limited Approach Boundary for shock protection

2. Where in the world should we put the Arc Flash Labels on our Buss Duct. We are usually standing on our head when we are working on them, there is a 1/4" of dust on top of them, and a lightening bug puts out more light than we got up there. I know they say you have to put them on, but I'm beginning to wonder if we would not be better off to put these on the entrance points to go up to the buss duct.

Probably Fixed. The festoon or burshes or whatever is moving is probably the moveable part.
I forgot about cranes. I never even thought about them. I don't think I have any exposed rails though.



We are putting them every so many feet(I think every 10') on the side where the disconnect box would go. I don't think it is necessary to label them though. I can't find in the 70E where it says you need to label anything. It says you need to document, and the permit is supposed to state the hazard, and its supposed to be communicated to the workers before they begin work. We agreed amongst ourselves to label everything in our facility.

Thats true, 400.11 states that it "shall be field marked to warn qualified persons of potential electric arc flash hazards"

I guess a simple arc flash symbol would work but seems kind of worthless if thats all the info it gives you. I'll go with your method and put them every 10' or so and make a label at the access point also giving the information. That should cover it and while they say you must have them on the panel, they don't say you can't put them somewhere else also so it should be ok.

Plus they will actually be able to read them at the access points

Whats your take on this one. I thinks it's a little overboard but I could be wrong. I was looking for some info on our fuses and found the following faq at http://www.ferrazshawmut.com/arcflash/faq/#1

QUOTE

Obviously this is not from any agency and the only justification I can find for it is a very strict reading of the NFPA 70E.

My problem with this is many of our guys who are qualified for lockout/tagout are not, and don't plan to be, qualified for working on live parts. They turn the disconnect off, lock it out, then test for voltage. They are mechanical guys. We are going to familiarize them with flash protection but don't feel that they should be working on live equipment. Are we suppose to train them and provide them with arc flash equipment to fill a tank up with oil?

Beuwolf_1 - I forgot to tell you, I got the NFPA 70E Handbook of Electrical Safety in the Workplace (Blue Book) and it gives so very helpful interpretations. You may think about getting it.

400.11 There it is.
This reminds me of all the other warning labels in the world. Sometimes I think we should junk all the labels and go back to using darwin rules full time.



Ahh! Another sore topic. I think this is going too far, but our plant policy is to do this. I personally rarely do this, because i know if something can be backfed or not, and i have dozens of lights, etc. that turn off when I turn the power off. There is my indicator. Another indicator is visually seeing if a disconnect switch is open or not. They now sell windows in disconnect switches to help with this. After all that I can still check for voltage just to make sure all three phases are off, but without my PPE. That's my opinion, not the rule.

Some european cabinets that I have seen, have a bright red light indicator(one light for each phase) when you open the panel, warning you if the power is still on.

http://www.elfin.it/english/bima/security.html Click on the Systems for Lighting and Signalling Catalog

I don't think we will implement the PPE for lockout. Getting them to wear the PPE while working on live equipment will be a major safety step for us.

Again thanks for all your help

I hope you all realize that this went from what I had hoped to be a rather simple question to a whole mess... LOL I'm glad to see that I'm not the only one that reads like mad, digs a deeper hole the more I read. I guess now to go back to another topic for just a moment. Who makes the best design engineer? At this moment, I'm gonna reflect on that and go with the advise of WWSD? (What would Scotty do?)

Time to read some more, and I really thank all of you with all the fine info that has me lap deep in reading material....

Thanks,

Beuwolf

Well after looking in the NFPA 70E blue book, looks like PPE is required during lockout procedures. It states in the notes for 120.1(3)


120.2(A) notes


Well that sucks. Will have to think about that on, might implement it later but I think the Flash protection will be more important when working on live equipment.

Beuwolf_1 - It's really not very hard. Go ahead and get the blue book, it clears up some of the grey areas. But mainly, use some common sense. We push lockout procedure more here and I get the feeling after we impement this Arc Flash protection will not be a big issue because what you have to go through to work on live equipment. I would say most will opt to shut the power off.

I went to a electrical safety seminar that these guys offered. It was more of a sales pitch but some of their products may be helpful for the programmer that has to open a box with live parts to connect to a controller. Plus they also offer voltage indicators that are visible from the outside.

http://www.grace-eng.com

So if you have an outside the cabinet indicating device like what is on this web site, is that considered a valid test for present voltage? Can you then open the door and use, say, your ohm meter to check a fuse, ( I would check for voltage first anyway, always), without PPE?

Technically no and I think I would rather check with some voltage tester. If the light bulb was burnt out someone may not pay attention before they think they have turned it off, turn and look at the light and say it's off. Article 120.1(5) states

Actually, the voltage indicator has a redundant circuit, so lamp brunout probably wouldn't be a big issue. I think that i would still double check before working on something electrical. But, it looks like a good device just to use for lockout/tagout verification.

I don't think I have seen what you are talking about. I have seen panels with power present lights but no redundancy. What is it, multiple light bulbs?

http://www.grace-eng.com/VoltageVision/DS-R-3W.shtml

This one.

Or, a window in a disconnect switch would accomplish the same thing.

Ok, thats a lot different than what I've seen on panels. I think I will look into them on our cranes. Depending on where the crane is parked and what they are doing, the service disconnects can be very hard to see. This would give them a little more assurance.

I was also awarded the task of helping with implementation in our plant. It ended up being a lot larger project than we anticipated and is still in the works after two years. We ended up hiring an outside firm to work with us. The first thing we did as a plant was to update our plant one line power prints from the out side transformers to the main switch gear to the supplied device. We gave the firm these prints and every panel was opened and fuse brand, type, and size was documented. This info was used with the SKM software to give the ratinings. We also hired them to give training, update our print library with the documentation for calculations and creating and installing about 1000 tags for the plant. The cost was about $35,000. All was stamped by a certified E.E.
Implementation in the plant is a bit dificult. About 90% of our panels came back as a Cat. 0 -long sleaves and pants. Work has provided all maint personel with FR uniforms for daily wear. We also provide each man with a pair of gloves, insulated screwdrivers and a new meter. None of this is something that was provided before. We have two Panel Rooms and I speced out 2 Cat 4 suits for each room and am in the procces of getting a hot stick and voltage "sniffer" (like the utility guys use) for each room as well.
Our plant has yet to establish a "policy" so I still see guys working foolishly -panel doors open and not within sight, etc.
I am fortunate in that I work for a large corperation that had a couple engineers train a guy from each plant and answer/interpret questions along the way. As far as working in panels with gloves, etc. there are exceptions and they are in the book. One thing to understand is that the Cat rating is for the power feeding the disconnect itself -not after. If this is understood and I am not at that part of the panel the risk is far less -the panel would be a zero after the disconnect. If you look at the "aproach boundries" and read through that portion you can see that if I am programing, adjusting a drive, or other such work and am 12" away from an exposed terminal I am alowd to have the gloves off. If I am checking for voltage at fuses, etc. then I need gloves to protect from shock hazards. If I turn the panel off for Lock Out I need to verify lack of voltage at the disconnect with the specifed PPE.
Until our plant implements a work policy I think I will still see broken disconnects, panels left unatended, or guys checking voltage without PPE. On the flip side I hope the training and focus on this project will help some of the rookies realize the hazards of electricity and respect the hazards.


Luke

Yes, that is something the Gerry stressed earlier. You must have a policy that employees must follow through on and be held accountable for violating.

And at $35,000 dollars, I would think someone would be pushing for it to be implemented.

This is a basic description of arc flash hazards that our maintenance supervisor had all maintenance employees, production supervisors and operators read. A bit technical for some people in places, but still some good info. Also I am not sure about the enforcement part it talks about. We just had a OHSA consultant in our plant and we asked him if any of the arc flash stuff was being enforced yet and he said no, but soon.

Thanks for the document. It has some good explainations I may use for introducing Arc Flash to the employees. We just about have all of our panels labeled and we have done some brief explanations of what is coming but we still need to have a class and explain details of Arc Flash protection.