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 Post subject: Glove usage for arc flash.
PostPosted: Tue Jul 08, 2014 9:01 am 
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Hello, I am pretty new to all the arc flash stuff. I have recently been given the task of getting our plants arc flash compliant. I am a journeyman electrician but now I am a process engineer. I have been reading and trying to understand all of the PPE and requirements. We have had the arc flash analysis done at three of our plants the last will be done next week. With all of this we have come to the conclusion that this changes our lock out tag out too.
One of my questions is gloves. Most of our devices roughly 95% have come in at Cat 0. I thought we were good. I have since found that Cat 0 requires gloves. Our actual labels on the machines don't list them. So, we have operators that will shut off a safety switch to lock it out for usual clean up and related work. That appears to me to require leather gloves or insulating gloves as required. I have been looking around online and ran across these:
Ansell PowerFlex 80-813 DuPont Kevlar Glove with Black Proprietary Soft Palm Coating

Item #: 808136 Model #: 103535
Brand: Ansell®
DuPont Kevlar cut resistant gloves; Yellow, 13 gauge, machine DuPont Kevlar liner; black, proprietary soft foam palm coating; EN 407 Level 4 flame resistance; Hazard/Risk Category (HRC) Level 2 Arc Flash Protection (ATPV) 12 cal/cm2 ; ANSI Level 4 cut protection; knit wrist; sizes 6-11.


For our average operator that might throw a safety switch and or breaker for LOTO would these not be fine? Our techs would have the insulating gloves as required for checking voltage etc.

Am I thinking wrong?

I am trying to find a way for the operator to do their normal operation and still maintain the arc flash safety without the need for a tech to throw a switch for LOTO.

Thanks

Joe


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Tue Jul 08, 2014 10:25 am 
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If you refer to NFPA 70E-2012, Table 130.7(C)(16) lists heavy duty leather gloves as protective equipment for the various HRCs. There are notes associated with the HRCs.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Tue Jul 08, 2014 10:53 am 
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I just read 130.7 and unless I am reading it wrong those gloves will be fine for arc flash burn. I don't feel that a safety switch or breaker puts you in a shock hazard. I am talking cat 0 & 1. Am I wrong? Trying to think easy to use and most apt to be used with fewest complaints from workers. If I'm wrong I'm wrong. Really I'm just wanting everyone to have a pair of gloves handy that they won't think twice about putting on.

Thanks

Joe


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Wed Jul 09, 2014 12:58 pm 
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There are really roughly 4 glove options (none, arc rated, leather, rubber) which depend on the conditions and there are several hazard/risk conditions as well to match up to (no risk, risk but minimal arc flash hazard, shock hazard only, arc flash hazard only, shock and arc flash hazard).

If this is an operator live working is outright not allowed so we can eliminate the shock hazard cases. That leaves just:
1. No or minimal risk. Do you wear arc flash protection to reset a breaker in your house? If not, why not? Specifying arc flash protection for ALL electrical tasks ignores the likelihood of an arc flash and makes the electrical and safety departments look like idiots...and seriously erodes their credibility on this and other issues.
2. If the hazard is under 1.2 cal/cm^2, we don't require any special PPE anyways currently under 70E because it is outside the arc flash hazard boundary. So even if an arc flash happened, no PPE is required.
3. If we get through the above two special cases, there are arc rated gloves on the market and the description above sounds like one of them. If operators aren't wearing the rest of the PPE that goes with it, this would be ridiculous as the point of arc flash PPE is to protect the head and face area. Loss of limbs does not generally cause death and right now the standards are not there to prevent injury (the threshold is a 2nd degree burn, not a first degree burn), but merely to prevent fatal ones.
4. All leather gloves and rubber gloves with leather protectors have been "type tested" which means any glove meeting the description is acceptable without needing an actual test for ATPV. Leather gloves are good for 8 cal and rubber gloves with leather protectors are good for 40 cal. Usually this is a better option than the arc rated gloves but with leather gloves rapidly falling out of favor in the industrial environment (great for abrasion, lousy for cuts, punctures, chemicals, liquids, and often comfort), other options are bound to pop up.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Thu Jul 10, 2014 6:19 am 
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Thanks PaulEngr.

I think I am going to go the route of the arc rated gloves for the LOTO in CAT 0 areas. Just so happens that all of our normal LOTO are cat 0. Anything higher will be in the hands of the Tech's any way.
The problem here is the PPE Category Level Chart for 2012 says that gloves are required for Cat 0. Our labels do not indicate that gloves are (as needed) that now means required to everyone involved. So with that everyone thinks they need there equipment de-energized for them. We do not have an ESP done yet so things are becoming very difficult. I think our mistake was to have the arc flash training before we had our plans in place. Then again some of the things brought up by people will help shape our ESP. Its kind of a catch 22. I am trying to see things as best I can from both the workers side and companies side to keep things moving and keep them safe. Its proving to be a very time consuming project.

Again, thanks for the input. Anything else you might want to suggest feel free. If you have any experience doing an ESP or have any suggestions for that I will use them.

Joe Meyer


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Thu Jul 10, 2014 10:01 am 
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jmeyer wrote:
Our labels do not indicate that gloves are (as needed) ...


Inflexibility is a problem of trying to put too much information on a label.

Do you put detailed PPE listings on all of your facility's other warning labels (e.g. for hazardous chemicals)?


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Fri Jul 11, 2014 7:26 pm 
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The PPE chart assumes you using the task table, too. If you did the engineering study, you assume responsibility for PPE selection and risk assessment, too, and the chart does not apply.There are vague informational notes alluding to this and the definition of arc flash hazard says it but for normal operation of equipment which has been properly installed and maintained, the risk of an arc flash hazard is minimal. The 2015 edition will make this much more apparent, as does OSHA's update to 1910.269, although that is for distribution and not utilization equipment. So my comment about gloves for breakers in your house was alluding to this. It also sounds like you are running up against the "qualified" definition. No one is qualified on everything. Linemen for instance usually have no business working on industrial drives. Operators can and should be trained to recognize basic electrical hazards and how to avoid them.This means recognizing broken conduits, downed lines, breakers that tripped as opposed to overload relays, open wires, etc. Training should include basic situational assessment...that water running down or out of an electrical panel means get help, and how to safely operate disconnects and breakers where you don't have to rack it out to lock it. It should include an understanding of barricade tape (caution or danger) that electricians should be using to warn unqualified personnel of hazards. But training for unqualified personnel should end with hazard recognition and avoidance. It should not involve hazard mitigation. 70E is pretty clear on this distinction and what unqualified personnel receive training on. So having unqualified personnel trained on using PPE to reduce hazards is working outside the required training. That being said my present employer went to something even more silly. Operations personnel are required to use 40 cal suits for LOTO. This ends up with silly situations like an electrician standing next to them in a cotton short sleeve shirt and jeans. We've gone so far as to even make it a two level system but so far, managers are knee jerking it and requiring 40 cal suits even for 120 volt lighting panels.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 14, 2014 6:17 am 
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I would recommend using leather gloves for cat 0 normal operation of breakers and disconnects. I don't designate "heavy duty" or anything other than "Leather Gloves". Keep in mind that your hands are much closer than 18 inches which is where the cat 0 is calculated to.

I recommend doing no more than this. If it is difficult to comply then we have a tendency to cheat and not comply when no one is looking.

Keep it simple but make is safer.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 14, 2014 8:11 am 
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Unbelievable comments and concepts here. Exactly why I got out of this arc flash/electrical safety work. Everything from moonsuits to no PPE use was interpreted for the same situation in different facilities. I felt that I was really bringing something useful and possibly life saving to my clients, some of whom are very large corporations who put all thought and energy into repelling litigation than to actual employee safety. After the fact finding and reporting the actual ESPs were non existent or just smoke, a document no one was responsible for or was really interested in, just something to have in the file for when the 'shit hits the fan'. Many employees were no more responsive to the realities of electrical safety than the 'girls in the office' were. It was just a subject of contention for most of them. The way I see this going I can't think things are getting better.

I visit this site weekly and have been interested in all the questions and opinions expressed. At this point it is just for my own safety and reference. If the standards and interpretations get any more convoluted I'll not have the interest in even reading about arc flash hazard anymore. I'm lucky this is an option for me. I feel for the people having to work in this field at this time.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 14, 2014 9:06 am 
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I agree with CarlM, we jsut need to answer the question. When working with Category 0 the operators at our stations wear long sleeve cotton shirts, jeans, safety toed shoes, safety glasses, ear plugs and their hard hats, with leather gloves. They are not qualified to do anything other than operate a breaker, disconnect, mcc bucket, or switch so they are never exposed to any shock hazard. We do keep the proper PPE avialable to them for when they operate equipment that has a higher category than 0.
Thanks!


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 14, 2014 4:59 pm 
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I agree with "Let's keep it simple". Joe for your operators who are operating disconnect switches for Lockout Procedures- a pair of good quality leather gloves. For your technicians performing troubleshooting, who could be in harms way of electrical shock, rubber insulating gloves with leather protectors.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 14, 2014 5:43 pm 
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Facility I worked in previously required long sleeves (non-flammable) and leather gloves for any person operating a disconnect or MCC switch. Most employees wore gloves anyway, so that wasn't much of an issue, and they kept gloves and welding jackets in the vicinity of disconnects that were to be operated by employees that typically wore short sleeves and/or no gloves.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Tue Jul 15, 2014 8:37 am 
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We have never specified PPE for LOTO. Most of our machines have plugs that get a cover locked on them. Some are typical fusible disconnects, ranging from 30 to 100 amps@ 240v 3 phase. A few have simple lockable rotary switch disconnects for the purpose. Many of these machines are locked out 2 or 3 times a day during setup.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Tue Jul 15, 2014 11:54 am 
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CarlM wrote:
Unbelievable comments and concepts here. Exactly why I got out of this arc flash/electrical safety work. Everything from moonsuits to no PPE use was interpreted for the same situation in different facilities. I felt that I was really bringing something useful and possibly life saving to my clients, some of whom are very large corporations who put all thought and energy into repelling litigation than to actual employee safety. After the fact finding and reporting the actual ESPs were non existent or just smoke, a document no one was responsible for or was really interested in, just something to have in the file for when the 'shit hits the fan'. Many employees were no more responsive to the realities of electrical safety than the 'girls in the office' were. It was just a subject of contention for most of them. The way I see this going I can't think things are getting better.

I visit this site weekly and have been interested in all the questions and opinions expressed. At this point it is just for my own safety and reference. If the standards and interpretations get any more convoluted I'll not have the interest in even reading about arc flash hazard anymore. I'm lucky this is an option for me. I feel for the people having to work in this field at this time.


First, I can understand the frustration. I was there myself about 10 years ago when "arc flash" entered the NEC for the first time and at the time, the 2000 edition NFPA 70E was lousy at best and the only folks promoting arc flash safety were arc flash consultants out there flocking like sea gulls (fly in, crap all over, fly out).

Second, to summarize, what we currently have is a lot of study work that has occurred over the past 20 years. The results are very surprising, and continue to turn up new surprises all the time. However arcs are also highly variable so you can run the same test several times and get different results, often significantly different results. The current most widely recognized engineering standard (IEEE 1584) used a relatively fixed set of test conditions designed to simulate an "average" size MCC bucket. However it does not do so well simulating panelboards, open air conditions, DC systems, switchgear, or other gear in which the box size is different. It also falls down depending on the shape and position (angle) of the bus bars/cables. It also depends on the phase angle at the moment the arc starts and it depends on the X/R ratio (motor loads vs. lighting loads change the results). All of these other factors change the results. So the end result is that something as "simple" as how "bad" an arc flash can get is actually not all that well quantified. So before even consideirng anything else, suggesting that "one size fits all" is simply not true.

Not only that but several other factors come into play. When it comes to electrical safety, protective devices (disconnects, breakers and fuses) play a huge role. That equipment has to work correctly and has to be maintained. Trouble is that breakers are notoriously hard to maintain as a rule. They don't necessarily even indicate that something is wrong until they are called upon to stop a fault in progress. Thus maintenance of equipment becomes a huge and very important issue to deal with. There are however no good "what is good maintenance" standards out there right now.

Furhter, there are all kinds of facility-specific issues to deal with. Plants dealing with conductive dusts such as foundries, carbon fiber/fiberglass shops, brine plants, and a lot of metal working shops have serious problems with highly electrically conductive dusts (that are often also thermally very insulative). This means that even the atc of opening a panel, something which is frequently very safe in many other facilities, can be extremely hazardous in and of itself.

Then we move on to other factors. Starting about 15 years ago, there was a sea change in the way the "safety" analysis gets done. Previously we had a lot of prescriptive standards which means that you do everything one and only one way according to the standard. Over time it has become very clear that we can't have a one-size-fits-all solution. For instance when it comes to burners, the safety precautions used for a backyard grill are very different from that of a oxyacetylene torch and different again with a manually lit boiler, and different again with one that is 100% automatic, and different again with different fuels (oil, gas, coal). Instead most safety standards have gone down the road of looking at acceptable risk. This concept is concerned with not only "how bad is it" but also "and how likely is it". We can't go around protecting everyone from every hazard in every situation. There are now even semi-numerical methods for being able to say when something is "safe enough". This concept has been in use for several years (decades in some cases) across chemical, nuclear, robotics, and a lot of other "high risk" industries but only slowly trickling down to other areas such as electrical safety. Some operations are already very familiar with these concepts and use it on a regular basis. Others have never even heard of it and just want someone to "tell me what to do".

And since the whole area of electrical safety is relatively new, and by the way highly profitable for many consultants, there are lots of opinions floating around, all pushing and tugging in different directions dealing with the exact same problem.

So when you say, "Everything from moonsuits to no PPE use was interpreted for the same situation in different facilities." No, it's not the same situation everywhere. There is no one-size-fits-all answer. And that is once you get past all the "noise" out there and settle on just the hard, simple facts.

Hence the reason that I was one of the ones articulating everything from one extreme to the other. I was by the way suggesting that many individuals where I work at now promoting the idea that "moon suits" are some sort of security blanket that make all these concerns magically go away are all wet. I used them as an illustration of how not to do things...by knee jerking it.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Jul 21, 2014 7:11 am 
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Paul,
My comment about different PPE requirements in different plants was not in reference to actual working conditions and electrical situations but of the different intellectual climate of the people involved with this subject. I can deal with the difference in a manufacturing clean room vs. a petroleum plant. It's the people, the management that either go too far or those who hire a consultant and put the report in a file cabinet. And the difference between workers who embrace the idea of improving electrical safety and those who reject any changes in the way things have been done. That is where I've been disappointed. Also I have seen more PPE studies and labeling that are grossly inaccurate. There are a lot of hacks in the game.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Thu Jul 24, 2014 11:22 am 
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CarlM wrote:
Paul,
My comment about different PPE requirements in different plants was not in reference to actual working conditions and electrical situations but of the different intellectual climate of the people involved with this subject. I can deal with the difference in a manufacturing clean room vs. a petroleum plant. It's the people, the management that either go too far or those who hire a consultant and put the report in a file cabinet. And the difference between workers who embrace the idea of improving electrical safety and those who reject any changes in the way things have been done. That is where I've been disappointed. Also I have seen more PPE studies and labeling that are grossly inaccurate. There are a lot of hacks in the game.


I can agree with that sentiment. If we narrow the focus to just arc flash, the 2012 edition of the 70E Code provides just one method for doing the estimate which is a set of tables. Those tables all rely on a set of published assumptions. The only way to verify the assumptions is....to do a full blown engineering study!

At this site at one time they used what I'm just going to call the "quick" method for estimating the values. This is the same method that you see frequently done for short circuit calculations. Speciifically, iignore motor and capacitor contributions and assume that all cables have zero impedance. Finally, assume infinite available power on the primary side of transformers. As long as the motors are not too terribly large and there aren't a lot of them, this results in a relatively conservative estimate of maximum short circuit current which is good enough for sizing cables and other equipment.

There are huge problems with this, though. It can underpredict the contribution of motors to fault currents. And more importantly, it totally ignores impedances which are real and have a huge influence on the actual short circuit currents. Thus it results in a significantly higher current, which will give a false indication of how quickly protection devices will trip, and usually results in a relatively low arc flash estimate. However this "quick-and-dirty" method which is not too far off from the ANSI method is what was actually done for short circuit calculations for years. In fact that is what the first arc flash estimate for the plant I'm at now used.

A more detailed and thorough approach does just the opposite and gives more relatistic values which frequently result in much higher and accurate results for both currents and arc flash. On top of that take the more detailed version we got here 5 years ago and a glaring problem with it is that it ignored VFD's, many of which were operating motors and had limited capability for transferring fault currents from the loads. Introduciing these into the estimate drastically dropped the original values.

Finally, and this is where I agree with you, you are on your own as far as determining what the real risks are. That is, the likelihood of injury and the extent of those injuries. OSHA data shows that arc flash injuries rarely happen below 250 V. And they show that arc flash events are very rare (roughly 1 in 100,000 workers per year), and they show that of those injured severely, only about 1 in 10 actually dies. This number has improved over the years, roughly dropping by 60% since around 2000, so the arc flash ideas are having an effect. But there is still a lot of unknowns and site specific things. For instance on a lot of draw-out breakers that I've been working with over the last couple weeks, the door is more or less just a cover with a hole in it that keeps foreign objects out of the breaker mechanism. Behind that door, there really aren't any exposed conductors, either. The major danger from an arc flash point of view is racking the breaker on and off the bus. Yet the various standards suggest that opening the door is a risk that should not be taken without protection. On the other hand I have lots of MCC's, many of which contractors in the area always gave plenty of extra slack (sloppy work) in the wireways, often FEET worth of excess cable, thinking they were doing us a favor. This makes it really easy to have cable flop out and move when you open the door to an MCC, as well as provides a definite hazard of pinching a cable when closing the door. So...same activity, different outcomes. There are plenty of consultants though that say that opening doors is not a major hazard, and others that say they are. Both are right, in the right circumstances. For the record there are even some OSHA accident investigations where either event resulted in an arc flash. So it's not to say that it's not possible but in the first case it is highly unlikely, and in the latter depending on conditions it might be very possible. So should the standard develop towards "don't worry about doors", or towards of aminimum standard such as "be careful of debris or defective equipment when opening doors, and be mindful not to pinch cables while closing doors"? It's hard to say because from a highly litigious point of view the standard has to say "wear PPE when opening or closing doors" but then leaves the concept open to different local interpretations. If this is not asking for a diversity of opinions and arguments for/against a standard, I don't know what is.


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 Post subject: Re: Glove usage for arc flash.
PostPosted: Mon Aug 18, 2014 4:31 pm 
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I tested the Ansell PowerFlex and they work quite well in arc flash. The front side of the glove and tips of the fingers which are coated take over 25 cal. The rating in ONLY on the back of the hand. Leather works too in NFPA 70E. The NEW OSHA 1910.269 requires 14 cal protection or leather.

Don't know that this is necessary but this is what the standard says.

Hugh Hoagland
e-Hazard.com


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