There have been many changes to the 2015 edition of NFPA 70E. Many of these changes were described in this article previously posted here: Changes to 2015 NFPA 70E

This week's Question of the Week:

Which change to the 2015 NFPA 70E is the most significant?

Change from Hazard Analysis to Risk Assessment
Deletion of Category 0
Deleted Hazard/Risk Category Table (now PPE Category)
Explicitly prohibiting using incident energy AND PPE category together
Something else (please describe)

Normal Operations- Allowing operators to operate MCC, Breakers, etc.. under normal operations without Arc Rated PPE

Besides many changes that we have seen in NFPA 70E 2015, the most significant changes to me is "Explicitly prohibiting using incident energy AND PPE category together". With these changes, if we perform arc flash risk assessment using Incident Energy Analysis method, we have to follow Annex H, Table H.3(b) for protective clothing & PPE selection. To me, I like this, because it was simplified to three PPE descriptions (< or =1.2 cal/cm^2;>or =1.2 cal/cm^2 to 12 cal/cm^2; and >=12 cal/cm^2). Of course, a great care should be taken while selecting the required PPE. And if we use Arc Flash PPE Category method to determine PPE, we have to use Table 130.7(C)(15) & Table 130.7(C)(16). However, most of the arc flash labels that we see in the field till date contain both incident energy and PPE Category. And now, when there is no PPE category on arc flash labels (performed using Incident Energy Method), many technicians may react like bring back our PPE Category , because they had been so much used to in understating the risk by PPE Category (formerly known as Hazard/Risk Category). So, the NFPA 70E 2015 edition is also a testimony for willingness to change and adaptability

There seems to be some special semantics involved when stating: "Explicitly prohibiting using incident energy AND PPE category together"

When I perform a hazard risk analysis, methods of IEEE 1584 are employed to determine the calories per cm2. Based on those calculated calories/cm2 results we then post HRC without applying further risk factor. The PPE requirements for HRC 1, 2, 3 or 4 are printed on the labels as described in NFPA 70E, as a reminder to the workers. This combination of PPE description and calculated incident energy is preferred by some agencies.

We do NOT combine results from the tables based on 'type of work' that apparently include a risk factor, however; that is
1) an inequity imposed against those calculating actual caloric exposure: all chores are given equal (maximum? ) risk, and
2) depending on how the words above could be interpreted by a jury of laymen, could constitute violation of "explicitly prohibiting using incident energy AND PPE category together".

Methinks this is cutting-room floor stuff.

Going back to 70E-2012 for instance with a medium voltage starter, operating the starter (contact closure operation) with the doors closed is H/RC 0. Work on the exact same starter while energized is H/RC 4.

There are 3 steps going on in the background. First someone calculated (or measured) the incident energy and generally determined the hazard. Second, the likelihood of the hazard occurring (risk analysis) was performed and then for some tasks where the risk was determined to be very low (arc flash very unlkely), the H/RC level was adjusted downwards. Third, with this information in hand, PPE was determined based on the H/RC score.

If you perform an engineering study using IEEE 1584 then this is step 1. Steps 2 and 3 must still be done. Thus it would be incorrect to assign an H/RC level (and use the PPE table) if only incident energy was determined and that the risk was not addressed. Risk should be addressed under one of the many risk assessment standards. This is still an engineering study albeit a safety engineering study. This then arrives at a risk-based score and then necessary PPE (if any) can be determined based on the risk assessment.

It would be incorrect to take a hazard analysis and then convert this into an H/RC score and then subsequently into PPE because the risk assessment step has been skipped. That being said, a whole lot of engineering studies have used IEEE 1584 and then skipped the risk assessment step and just made the assumption that all electrical equipment is inherently dangerous. However following OSHA guidance on this condition the correct approach is that it cannot be used (unsafe). This is akin to working with mechanical equipment without guards as long as the workers wear gloves for protection.

Under 70E-2015, this methodology issue changes somewhat. The first table is a risk assessment. The second table is pretty much a straight up hazard assessment, and the third table is PPE. One could effectively review/validate the first table as a risk assessment and then substitute IEEE 1584 for thesecond table, and then follow up with the existing PPE table. Strictly speaking this is adopting rather than using but it still requires some kind of engineeering study. Thus the comment is akin to using NEC for mining equipment instalations despite the fact that the preamble says it does not apply. The moratorium on mixing incident energy and risk assessments is now academic rather than real because they are separated.

Operating the starter with door closed and working on it while energized with door open are so to speak "two big differences" and incident energy exposure during arc fault has nothing to do with risk factor here. There is no incident energy exposure with the doors closed, hence hazard level is 0 cal/cm2. Working on the exact same starter while energized could result in significant incident energy exposure, hence hazard level could be very high.

Downwards adjusting the H/RC level based on assumption the risk is low and sizing PPE based on the H/RC score as proposed above sounds to me like advising quilted jacket against protection from bullets instead of bullet proof vest just because the risk of being shot seems low. Indeed, tactical body armor is rated in terms of its ability to stop bullets. The rating does not take into account probability of being shot, instead it assumes the worst 100% probability one is shot indeed. In other words, bullet vest will either protect you or not. Similarly, arc rated PPE is assessed in terms of its ability to withstand incident energy it is rated to. PPE rated less than incident energy it is exposed to could ignite and cause more damage than no PPE at all. Hence, PPE is commonly selected based on calculated incident energy, not based on H/RC level derived by risk assessment using downwards adjustment techniques etc.

Regarding newly modified NFPA 70E-2015 table method, it is now outright unusable and I would forget about 70E table method due to the inherent controversy introduced in the year 2015 edition. Read this forum thread at http://arcflashforum.com/viewtopic.php?f=34&t=3443 for more information.

Careful here. I articulated the logic of the tables. I certainly didn't agree with it. In terms of the invalid logic used to recommend H/RC 0, 2, and 4 for the same equipment in the tables in at least the 2000-2012 editions (the ones I've had copies of), there is no disagreement from me. In this regard, the 30,000 foot logic of the new tables (first, do you need PPE? Second, what is the hazard of the equipment you are working on? Third, what PPE is needed?) is great.

Your argument is that because the second table cannot be practically implemented without the exact same effort required to perform an analysis via IEEE 1584 is also valid at least from an academic point of view.

But let's just suppose for a moment that the "client" in this case is a small warehousing operation, perhaps even a "storage rental" office or an office building of some sort. The software alone runs $5K+ assuming that the prospective owner is actually an engineer perfectly capable of performing the analysis, assuming the prospective individual does not have days or weeks to grind through the analysis equations by hand, checking and rechecking results. Granted the online software that you make available significantly decreases the up front cost assuming that some of the key data (impedances) is easily obtained. There is the rub though...determining impedances to each bus is the time consuming, complicated, error prone part of the process. This is never mind the fact that said individual probably doesn't have a PE license even though many have suggested that only someone with a PE license should be considered qualified to perform an arc flash study. That leaves paying an engineering firm and the minimum price is usually $10K and goes up to around $30K for a "small" site, and gets well over $100K for a large site. For the record my "bill" for a 5 year arc flash study is $200K for my site and this was the lowest of multiple bidders. That also happens to be a significant piece, if not the majority of, the annual profit of many warehouse/office building operations.

Even under the best of circumstances, any said business owner is definitely going to do a cost-benefit analysis and consider whether the engineering study is even worth it. And given the cost/benefit, they are unlikely to buy into such a thing. I worked at a 28 man sand mine 10 years ago and the boss wouldn't even consider it then, and we were a "progressive" company, willing to do most anything when it came to safety. The $30K quote we received was equal to about 5% of the gross margin. Safety (and profit) were important, but there were a lot of other safety initiatives worth doing with $30K and at the time (2003), NFPA 70E (2000 edition) looked like a great way to enrich specialists and engineering firms since it was clear then (as now) that there was no intent in the Code to make it practically possible for an average business to do the analysis themselves, and at that time, OSHA and MSHA did not have "arc flash" on the radar. MSHA still doesn't.

And this is the money argument. It does not even begin to address all manner of temporary setups such as test drill rigs, travelling service crews, logging camps, and portable agggregate plants for instance where such an arc flash study would have to be done every few DAYS. In this case again although I think we can all recognize that IEEE 1584 or a similar arc flash calculation method has tremendous value and peace of mind, it is not practical for some circumstances.

Finally we have the most obvious use case which is when there is no arc flash study in the first place and the field inspection is being done to load the data into the arc flash study. It's a "chicken and egg" problem. But again, at least the tables are better than nothing at all.

Hence we arrive at the situation that is the sole reason that despite blatant, glaring problems with the methodology, as has been stated many times over, it is better than nothing. I consider the changes in the 2015 edition a huge step forward in terms of improving the overall safety and result. It still does not address the issue of how do we start with almost no data and provide reasonable estimates of incident energy. But simply rejecting the idea altogther without proposing a practical alternative is not realistic either.

It has been proven in a study on the subject by Doan that without any arc flash protection, injury is 95% likely. With just the (original) tables, it drops to 50%. With IEEE 1584 including the 1.2 cal/cm^2 assumption, it drops to 0%. With the new changes hopefully the 50% chance improves even more. But trying to suggest that an engineering analysis under IEEE 1584 is the only acceptable practice for ALL businesses is not realistic.

I see nothing wrong with offering exactly this...a solution that is essentially "0 cost" but still has a significant failure rate over doing nothing, or an option with a significant up front cost, but almost no failure rate. At least as a minimum we can avoid the situation where all of the other benefits of 70E (reducing exposures in the first place) are still deployed which in itself even if the tables were not used, is a significant reduction in likelihood of injury.

So...take the tables for what they are, imperfect but at least a solution for those situations where the full analysis is just not going to be done for whatever reason. If anything the only caveat here that I would have is that there is no discussion about failure/success when using the tables WITHOUT the little fine print notes on validity, which lets face it are meaningless because by the time you validate them, you already did all the leg work for IEEE 1584. At least then someone can go into it with their eyes wide open. Putting the full list of mandates and assumptions out there without acknwledging that the majority of the time that the use cases have to simply ignore the requirements is not recognizing the use cases that exist. Again...perhaps suggesting an imprved alternative would be more beneficial.

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My point is that it's better to stay away altogether from energized equipment than rely on PPE recommendations from the controversial NFPA table method. I see a big time problem with offering a solution that is essentially 0 cost but still has a significant failure rate over an option with up front cost but almost no failure rate. Going back to the tactical body armor analogy, you better have proper bullet proof vest while in the combat zone with bullets flying around. And stay away from the zone when only a quilted jacket of questionable quality is available means of protection.

Indeed, the full engineering arc flash analysis can always be done even with the most limited budget. While in fact the cost of most arc flash software programs runs $5K+, there are however alternate cost effective solutions, for example ARCAD's Short Circuit Analytic, Arc Flash Analytic software programs and mobile apps allowing average Joe to perform comprehensive short circuit, arc flash analysis, create arc flash labels meeting and exceeding OSHA and NFPA 70E standard requirements and regulations within $500 budget.

It must be hard realizing that there were and still are available free or very much affordable DIY solutions available (not requiring paid annual renewal fees, maintenance fees and other money grabbing tricks) when you have already spent a fortune on arc flash software and services. Don't worry life is easy and it's never late to give a try and switch to alternate resources.

I did not see the mention of the Informational Note that states that without proper maintenance and installation the incident energy calculations may not provide adequate results.

I do agree with the statement, but that are not clear cut requirements set to consider a piece of equipment properly maintained!

Yeah we have NFPA 70B and other standards, but 70 E note does not provide clear indication what to follow.

Maintenance is usually first thing clients cut from the budget and now what?
Do you still provide them with the risk analysis that they need because their insurance is requiring it knowing they are not providing maintenance as needed and cover yourself with an assumption in your study report?!

What do you guys think or do?

I understand this new statement in the 2015 version, but excuse me if I missed a topic discussing it, but where does the operation of the breakers and control panels under normal operations with risk analysis performed and labeled as dangerous or Cat 4?

I am not sure how to answer this question....in many cases I have the entire MCC or Switchboard rated High to Dangerous due to Main CB being part of the assembly and the rating of the gear is based on the line side of it.

Can anyone help me answer this?

I appreciate what you are saying here, however; how many independent agencies (not some government research trust) are willing to put their name on a "risk" assessment for typical arc flash analysis? I would venture none. So we simply list the calculated cal exposure and as a user convenience list the corresponding HRC (despite not being supposed to say that word anymore) with no devaluation for low risk jobs.

OSHA REQUIRES a risk assessment specifically for all plants using "highly hazardous chemicals". Four examples are ammonia, SO3 (even as flue gas), MIBK, and MEK. All are very common chemicals in many plants, not just places like Dupont or Dow. One is also required for any moving machinery such as assembly lines, presses, robots, and packaging. There are both generic and industry specific risk assessment standards, recognized by OSHA, for all of these. Fines have been issued for failure to do a risk assessment. The electrical industry is next with 70E-2015. Its just a matter of time. The ostrich approach does not work. All of the above industries have tried and failed.

A probability of an arc flash event, whether it is high or small, has no impact on the gravity of damage when the event occurs. Therefore, one should be properly protected in case the event takes place.

By deleting Category 0, it seems the NFPA 70E group has finally admitted that there is no such thing as a minimum incident energy for a second degree burn on a bare skin. Ultimately, it's all about how fast the energy is delivered. Very small energy exposures can cause damage as long as the energy is delivered fast enough. Also, huge amount of energy but delivered over long time interval could be perfectly safe. While being well informed and aware about the importance of energy flux rate in arc flash analysis, nonetheless the NFPA 70E group has not addressed the matter in new edition of the standard.

I also find very symbolic the fact the new NFPA 70E has explicitly prohibited using incident energy and PPE category together. While the standard does not elaborate why the prohibition, I hope the group may have finally realized that matching the PPE cal/cm^2 rating to incident energy exposure in cal/cm^2 will not necessarily protect a person wearing the garment. Namely, an "arc rated" PPE designed to withstand XYZ cal/cm^2 while the energy is delivered within relatively long time interval (0.5 or 1 sec per existing ASTM standard) most likely will set on fire and only aggravate the problem if same (or less) amount of energy is delivered at higher rate but within shorter time interval.

It seems confusing that the NFPA Handbook shows a sample label with fields to be filled in for "available incident energy" and "level of PPE", whilst just half a page earlier states that "available incident energy" cannot be included with the "PPE category" in table 130.7(c)15(A)(b).

In my mind (sorry to be late to this discovery), this indicates that the committee does not wish to mix methodology, however, listing the PPE based simply on available incident energy should not be a problem.

NFPA 70E provides Annex H as guidance for determining PPE when the engineered approach (calculating incident energy) is used. Annex H is a little more flexible since what would be called "PPE 2" goes all the way up to 12 cal/cm^2 before the hood and multilayer flash suit becomes a requirement instead of an option. Since a lot of PPE on the market today exceeds 8 cal/cm^2 this may allow additional flexibility.

This is an active discussion in my company now. In addition to providing various consulting services, including arc flash analysis, we have a great many manufacturing sites across the world that we need to be concerned with as the facility owner. We have considered using the tables for some small, simple sites that are well within the bounds of the notes and we came to a similar conclusion. As the owner we have to be able to document that we are compliant in addition to being complaint. By the time we gather the utility impedance and/or transformer data, determine which section of the table applies to each piece of equipment, and identify the equipment, we have expended almost as much effort and cost as we would with an IEEE 1584 arc flash study, and we have produced a result which is significantly less accurate than a study. Keeping this cost/benefit ratio in mind we have not been able to convince ourselves that the tables are the prudent course of action to use for our smaller sites that are within the scope of the tables.

Also note that an arc flash study for a small site can be completed by leading practitioners using the expensive software with annual fees for less than $10k that was previously mentioned. As awareness of arc flash hazards increases, I see increasing numbers of inexperienced and minimally trained folks performing analysis that is incomplete or seriously flawed. These situations are usually brought to my attention through an discussion about overdutied equipment or coordination problems, and after peeling back the onion there is often a flawed short circuit study, numerous miscoordinated OCPD, as well as notable errors in the arc flash analysis. Making arc flash analysis practical for individuals with less training and technical background is a fine goal if it results in increased safety for workers. Based on what I've seen in recent years we as an industry need to do a better job teaching folks about the gravity of this analysis and ensuring levels of training and engineering quality control commensurate with the importance of getting an accurate incident energy estimate.

Actually it does make sense as the "Level of PPE" and "PPE Category" are two different terms (grammatically at the least). Could someone make a shot of the page from NFPA Handbook showing the label and post it?

From a European point of view I just don’t understand why prohibiting using incident energy and PPE category together is a good thing. Our stance in Ireland/Europe where we carry out our studies is that incident energy is the most important piece of information and this is what we educate people on.

Although the NFPA70E standard is highly regarded and referred to in Ireland/Europe, it is outside Europe’s jurisdiction. For this reason coupled with the fact that our PPE is tested and rated in Cal/cm² (IS EN 61482-1-1 Live working – Protective clothing against the thermal hazards of an electric arc. Test Method 1 – Determination ATPV)

I do not see this as a productive move or one that will be adopted here in Europe (I should note that AF hazard is currently an open playing field in Europe and we are following the US very closely). The more information the better would be my opinion.

In Ireland our approach to tackling electrical safety is risk assessments. Under no circumstances should a non-electrically qualified person and/or someone who is not aware of all potential dangers, including AF, be responsible for carrying out an electrical risk assessment prior to live work commencing. This brings me back to my point, qualified people should understand the meaning of both incident energy and PPE category and will automatically know the relationship between the two - separating the two does not offer any other benefits.

That would be my thoughts anyway.

Andrew

There is a difference in terminology for the most part between European and North American safety standards. I'm not 100% sure how electrical hazards are driven n Canada but in the U.S. OSHA requires that PPE is selected to address recognized hazards and the risk assessment arises out of a PPE requirement in 29 CFR 1910.132. Now the catch here is that this section talks only about requiring PPE but the underlying assumption is that this is the method of last resort after all other options have been exhausted. OSHA does not reference it but is essentially invoking the principles inherent in ALARP/ALARA (ANSI Z10) which says that effectively we first try to engineer out the hazard, then try to minimize/eliminate it with administrative procedures and paperwork, and finally if all else fails, we use PPE. However because the principle of ALARP/ALARA is never mentioned anywhere in the regulation, it generally points to the idea that PPE is the one and only acceptable solution without even making reference to any others. In the European standards by contrast, the entire focus is for the most part on doing a risk assessment and reducing/minimizing/eliminating risk via the ALARP/ALARA concept, which is why for instance arc resistant equipment is much more prevalent.

Personally, I think that Europe got it right. There is a lot we can do in terms of risk assessment and that we should not get so focussed on the idea that PPE is the one and only answer to all situations. If we don't do this then all the available technological approaches to minimizing and/or eliminating arc flash hazards become expensive, extra options where in a relative sense, just purchasing and using PPE is financially far more attractive because the time and effort, not to mention the equipment and installation, to actually develop a permanent solution to arc flash all to often gets ignored.

And when I say this, I do not mean that a "risk assessment" is when someone reads and follows the label on equipment. Far from it. The risk assessment starts before the label is even developed and looks at the tasks and the risks and develops solutions to reduce the risk to as low as reasonably achieveable (European standards use practicable, U.S. standards use the word achievable). In the location I now work where there are around 1200 buses (SKM terms) in the power system study, 22% are under 1.2 cal/cm^2. There are more but at a certain point we stop modelling. 22 exceed 100 cal/cm^2 so wearing PPE is not an option. Just 7.2% exceed 1.2 cal/cm^2 in a trip time of 65 milliseconds or less (the limits of vaccuum breaker technology). Thus at first glance it at least appears that eventually as we ratchet things down over the years, we can theoretically get to under 1.2 cal/cm^2 plant wide.