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 Post subject: Are provisions in earlier editions valid until rescinded?
PostPosted: Wed Dec 23, 2015 7:09 am 
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When updating your arc flash program is it permissible to continue to use provisions listed in earlier editions of 70E if they have not be specifically rescinded?

The 2015 edition did specifically rescind some previous provisions, like Level 0 is eliminated, and the Prohibited approach boundary has been deleted.
But the 2015 edition is silent and other provisions that were in previous editions. Some examples.

1) 2009 cited the exemption from analysis for circuits 240V and under derived from 125KVA or less transformers. Since this was an incorrect extraction from IEEE 1584 which citec 'nominal' circuits under 240V (ie 208V) and, since the 2015 edition still recognizes the IEEE 1584 analysis method as a valid method - can we assume that this provision still applies and we are not mandated to perform analysis on circuits 240V and less, and 125KVA or less?
My assumption is that this is still a valid exemption.

2) 2009 130.1 Justification for Work. "If deenergizing the electrical circuit is infeasible due to equipment design or operational limitations, the task me be performed with the circuit energized. An example of infeasible due to equipment design might be that removing the source of voltage for a single instrument circuit would require a complete shutdown of a continuous process." The 2015 edition doesn't include this text, and one could argue that the text provided rescinds this justification. But does it?

3) 2009 Standing Work Permit "Permits that cover routine work tasks to be performed by trained and qualified employees can be written to cover a long period of time." There is no reference to this statement in 2015. So for routine tasks, like changing fuses, where are electricians are trained and qualified, we would have a 'Standing' work permit that covers the task and does not necessitate the writing a new Live work permit for each individual task. We are talking here 'routine' fuse changing like in common disconnects or MCC buckets, nothing unusual or atypical, and all low voltage. Is this concept still valid?

I see two approaches we can take;
The first, is to treat this similar to court cases. The law (Art 130) is evolving. Precedents and decisions of lower courts (earlier editions) are valid until overturned by higher courts (rescinded by text in later editions). This also makes logical sense. The concept of the 'long term permit' for routine work permits US factories to be productive. Is it really beneficial to anyone to write 500 live work permits to the same electrician over the course of a year to do the identical work each time? So my thought process is that we take the total 'evolution' of arc flash in its totality. If the NFPA feels the need to rescind a prior condition, like Level 0 - it does so in text, and in a manner that is specific, and not subject to interpretation or guessing the intent.

The second, and other approach, is that each new edition supersedes and cancels out, all previous editions. We only read and follow 2015, and make believe that earlier editions do not exits. If you were using the Long Term Routine Work Permit concept, you now drop it, and write permits for each and every task, even if they are identical and performed sequentially (even if the same day).

There is legal ramifications here as well. If I continue to operate with my 'Long term permit for routine work concept' and there is an accident and OSHA investigation, am I covered under the sense that I was conforming to NFPA 70E? Can I reference the 2009 edition as being valid since it was not rescinded?

How do we, as American Industry, deal with a safety guideline like Art 130, which is expensive to implement, and is initiating substantial changes with each edition?


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 Post subject: Re: Are provisions in earlier editions valid until rescinded
PostPosted: Wed Dec 23, 2015 1:28 pm 
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haze10 wrote:
When updating your arc flash program is it permissible to continue to use provisions listed in earlier editions of 70E if they have not be specifically rescinded?


First off, 70E is a consensus safety standard. It is similar to many other standards that are developed under the NFPA organization as well as several other organizations (ie, NFPA). However let's consider how three of them are treated: NFPA 70, NFPA 70B, and NFPA 70E. These are respectively, an equipment standard, and maintenance standard, and a work practice standard. All 50 States reference NFPA 70 and treat it as regulatory. At the opposite extreme, NFPA 70B is referenced in an Informational Note (that is, NOT CODE) within 70E but it doesn't really get recognized anywhere else. So it is simply an engineering standard. Finally 70E falls somewhere in between. It is not specifically referenced by OSHA or most state standards but it has been cited by those same organizations as a reference standard.

With NEC, violation of the "Code" is basically the same as violating a regulation and it is treated as such. With NFPA 70E organizations are free to implement any safety rules they want, but OSHA and state organizations hold them to taking steps to prevent injuries to employees from burns and shocks. 70E does not carry greater weight than any other equivalent safety standard such as IEEE 516 (that OSHA and 70E both actually reference) for shock protection but today it is somewhat of a de facto standard. OSHA and other organizations also don't reference any particular edition of the standard. Indeed, MSHA (the mining portion of OSHA) references only the 1976 edition of NEC and OSHA themselves more or less adopted an early 1990's edition of NFPA 70E into regulation.

So when we get down to arguments in a court of law, it goes something like this. You can argue that you are doing the "right thing". This carries the burden of proof of proving what "the right thing" is as well as proving that it was being followed. With an engineering standard or any industry consensus safety standard such as PMMI for packaging systems, it's only necessary to prove that it was being followed. The burden of proving the consensus safety standard is nonexistent unless one were to get into arguments of who has the better standard. Although the battles between IEEE and NFPA are infamous, it is mostly just nuanced differences.

So in answer to your question...we're splitting hairs here to begin with but the key is to understand the "why's" of the provisions in 70E in the process of crafting your own standards. "Category 0" was thrown out for good reason...there's no justification for it. 1.2 cal/cm^2 is a standard based on burn injuries to bare skin. So it makes no difference whether you are standing completely naked in front of a panel, dressed out in shorts and a T-shirt, or in "standard industrial workwear", up until the point that the clothing melts or catches fire and becomes a greater hazard. So the committee removed all the "category 0" stuff for good reason...it was not justifiable.

Similarly, the Code has had provisions for risk assessments and recognized that electrical equipment is not inherently dangerous that is properly functioning at least back as far as the 2004 edition. It is only during the execution of certain tasks and when the equipment is not functioning properly (mostly that the condition is "unknown") that the risk of an injury increases to the point where steps need to be taken to avoid injury. It is only in the 2015 edition that finally rather than dance around the subject, steps were taken to make this more clear. And the 2018 version is shaping up to be even more evident.

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The 2015 edition did specifically rescind some previous provisions, like Level 0 is eliminated, and the Prohibited approach boundary has been deleted.


It doesn't "rescind" anything. The 2015 edition is a complete document intended to be read without reference to previous editions. It is not structured like legal documents that build on each other.

Quote:
But the 2015 edition is silent and other provisions that were in previous editions. Some examples.

1) 2009 cited the exemption from analysis for circuits 240V and under derived from 125KVA or less transformers. Since this was an incorrect extraction from IEEE 1584 which citec 'nominal' circuits under 240V (ie 208V) and, since the 2015 edition still recognizes the IEEE 1584 analysis method as a valid method - can we assume that this provision still applies and we are not mandated to perform analysis on circuits 240V and less, and 125KVA or less?
My assumption is that this is still a valid exemption.


Yes and no. This is a conclusion that is specific to one arc flash analysis method. 70E cites something like a half dozen in the annex and there are others that are equally valid. It does not make a value judgement as to which is the best. So if you go with IEEE 1584, then the exemption applies. If you go with say the Lee method, then it doesn't.

That being said, the exemption is under review. In the next IEEE 1584 edition, it will change. Precisely what it changes to is still under debate. There is some lab evidence that it is invalid. So this is an area where as I said, your local standards may be based at least partly on 70E and may be based on other information as well.

Quote:
2) 2009 130.1 Justification for Work. "If deenergizing the electrical circuit is infeasible due to equipment design or operational limitations, the task me be performed with the circuit energized. An example of infeasible due to equipment design might be that removing the source of voltage for a single instrument circuit would require a complete shutdown of a continuous process." The 2015 edition doesn't include this text, and one could argue that the text provided rescinds this justification. But does it?


Even if it doesn't, this is the exact verbiage in the OSHA standard. Then again, OSHA copied it from 70E! This exception by the way has been abused substantially and it's a good thing to get rid of it. OSHA has a letter of interpretation explaining the exact meaning and attributing it to a "get out of jail free" card for the process industries is not what is meant. OSHA describes it as specifically making allowances for when the work going on would create a greater hazard such as shutting down a ventilation system that prevents a hazardous atmosphere from occurring around a starter where the starter controls the fan motor. What it does not exempt is loss of production. In fact I haven't ever encountered a situation where once loss of production is acceptable, that the exception is needed. Most of the time the better rule is the greater hazard rule where loss of production also means a large amount of cleanup/maintenance jobs that entail significantly greater exposure to hazards. That's also the argument that hospitals make with regards to working on life support equipment live.

Quote:
3) 2009 Standing Work Permit "Permits that cover routine work tasks to be performed by trained and qualified employees can be written to cover a long period of time." There is no reference to this statement in 2015. So for routine tasks, like changing fuses, where are electricians are trained and qualified, we would have a 'Standing' work permit that covers the task and does not necessitate the writing a new Live work permit for each individual task. We are talking here 'routine' fuse changing like in common disconnects or MCC buckets, nothing unusual or atypical, and all low voltage. Is this concept still valid?


No. De-energizing requires energized work, but the three tasks that require energized work are operating a disconnection means, applying temporary protective grounding (if needed), and testing for absence of voltage. The first one is operating equipment, so no permit needed. The third one is already covered under the blanket exceptions (testing) so again, no permit needed. Only the grounding MIGHT require a permit but doesn't. Under the original (pre-2012) layout, work was captured in Article 110 in general. It was either de-energizing/de-energized (triggering chapter 120) or energized (triggering chapter 130). But the provisions for shock and arc flash protection were stuffed under Article 130. So in the 2012 edition they got rid of Article 110 and incorporated all the provisions under Article 130. But the same principle applies. De-energized work, including the means of achieving it, don't require a permit. Otherwise why even bother working de-energized in the first place? The paperwork is the same either way and it encourages poor work behavior (I got the permit, might as well just pull the fuses out while they're hot!)

Where a "standing" permit would apply is in routine tasks that fall under the greater hazard rule such as if you allow work on control wiring in a 480 V MCC bucket. Since everything is already not exposed in a 480 V bucket (if terminated properly), doing troubleshooting on 120 V control circuits has a restricted approach boundary of "avoid contact". As long as you're not fishing wires blindly and so forth, there is almost no arc flash hazard and this is acknowledged in the informational notes. But the ridiculous way in which 130.1 is written requires a permit when you cross the limited approach boundary. Similarly there are problems with even visual tasks such as opening doors and doing visual inspections.

But more to the point many sites recognize that for instance somewhere around a 50-100 A breaker or smaller, the incident energy for 480 V equipment such as small lighting transformers and such is well below the 1.2 cal/cm^2 threshold. So they often recognize this as a group and make a safety rule (aka "standing work permit") to allow this kind of activity irrespective of what 70E says. And sometimes such as with cutouts even though they are not exposed if they are mounted 12 feet off the ground and have to be operated with a hot stick, someone gets confused about the basic issue (safety) and thus the "standing" permit is the way out of a quandry of silliness.

Quote:
I see two approaches we can take;
The first, is to treat this similar to court cases. The law (Art 130) is evolving. Precedents and decisions of lower courts (earlier editions) are valid until overturned by higher courts (rescinded by text in later editions). This also makes logical sense. The concept of the 'long term permit' for routine work permits US factories to be productive. Is it really beneficial to anyone to write 500 live work permits to the same electrician over the course of a year to do the identical work each time? So my thought process is that we take the total 'evolution' of arc flash in its totality. If the NFPA feels the need to rescind a prior condition, like Level 0 - it does so in text, and in a manner that is specific, and not subject to interpretation or guessing the intent.


If you are writing 500 permits, you're doing something wrong. It's an administrative procedure to make it harder to do energized work. If you are issuing permits to do work de-energized, then you're not following the Code correctly. There are some sites that get this confused and thus we get stupid knee jerk responses.

Second, no, rules of "precedent" don't apply here. 70E-2015 is meant to be self-contained, as is 70E-2012. With each new edition of 70 (NEC), each state has to look at it and "ratify" it at which point it becomes regulation in its entirety. The only catch here is that construction done under an earlier Code generally holds to that Code. Modifications require bringing it up to Code. So if I replace a receptacle in a house today I can use the $0.50 receptacle without the safety shutters. But if I add a receptacle, then I need to buy the $1 one with the shutters. If I put it near a sink or outdoors then it has to be GFCI unless I'm just replacing an existing one.

In rare cases (and this is generally pretty widely published), sometimes the various rules and regulations are made "retroactive". As an example OSHA made it retroactive to require lockout points in industrial establishments but gave a large number of years to bring equipment up to standards to comply. But, these are rare.

Quote:
The second, and other approach, is that each new edition supersedes and cancels out, all previous editions. We only read and follow 2015, and make believe that earlier editions do not exits. If you were using the Long Term Routine Work Permit concept, you now drop it, and write permits for each and every task, even if they are identical and performed sequentially (even if the same day).

There is legal ramifications here as well. If I continue to operate with my 'Long term permit for routine work concept' and there is an accident and OSHA investigation, am I covered under the sense that I was conforming to NFPA 70E? Can I reference the 2009 edition as being valid since it was not rescinded?

How do we, as American Industry, deal with a safety guideline like Art 130, which is expensive to implement, and is initiating substantial changes with each edition?


This is the correct interpretation. But OSHA is not into splitting hairs. OSHA's rule has been and will continue to be that employers must make efforts to protect their employees from RECOGNIZED hazards. As an example arc blast is a known hazard but as of today there really isn't much of any kind of consensus agreement (and a standard) written for it so there's no way to hold employers to doing anything about it. So again going back to my first point, you pick your consensus safety standard (or standards) and you follow it, or if you deviate from it, you should document why you are doing so. OSHA does not claim to be better at understanding the hazards than the approach taken by committees of experts that create nationally recognized safety standards. And they are not going to argue over the nuances of one edition over the other. If you want to stick with 2004 edition for another 10 years, as long as you can show compliance, they're not going to split hairs over what is in the 2009, 2012, or 2015 edition vs. 2004 or even 2000.

The reason why you want to use the latest regulations is because once the proposal and comment period is over, the regulations are LAW. There is no more wiggle room except in court. The regulator doesn't care about your situation or whether or not the regulation is defective, only whether or not you comply with the regulation. As an example North Carolina where I'm at still uses the 2011 NEC. As the legislature and the Code group are handling it now we are likely to not adopt another Code until 2019, and even then they are likely to put it off until 6 years later and only then adopt the 2023 edition of NEC. So we will go for over 10 years without an update. This is ridiculous but that's how it is.

If you notice though the trigger is not a new edition of NEC but a new regulation which references NEC. As a practical matter most engineering firms publish laundry lists of standards that read something like "the latest edition of NFPA 70, NFPA 79..." (and probably have NOT read them), in the same section where they say something like "comply with the current regulations of XXX State" which is clearly a conflict in itself. As a practical matter I've gotten into arguments with federal and state inspectors because typically I've implemented the latest edition of a Code and they're still referencing one that is between 3 and 10 years older. I have never had a problem with acceptance of the newer edition. But again, inspectors are not into arguing details at that level.

Above all, if you take 10 engineers and put a question to them, you will typically get 20 answers back. The design of the process for NFPA and IEEE is to get a consensus opinion out of a panel of experts such as engineers that can rarely agree on anything. In this manner, they are no better than lawyers who can also do the same thing in the general case, arguing the same issue on multiple levels, and when both lawyers can come to opposite conclusions even when the basic facts of the case are not in question.

OVerall, it sounds like something is wrong with how you are (mis)interpreting the requirements for an energized work permit. The requirements are quite simple. If you are crossing the limited approach boundary OR you are doing something that can be reasonably expected to cause an arc flash, then a permit is required. The exceptions to this rule are when doing testing, troubleshooting, operating disconnects or otherwise doing energizing/de-energizing, visual observations, or for anything under 50 V. But incrementing into it further, the limited approach boundary does not exist if the equipment is not EXPOSED. Exposed means that it is not insulated, guarded, or inaccessible. Read the definition of guarding in particular because just because you can visually see metal doesn't mean that it is exposed. In most cases equipment isn't exposed. An example of exposed equipment is most panelboards with the covers off. A counterexample is most MCC's because even though copper is visible, it doesn't exceed the guarded definition. As an example inside an MCC bucket even though there is clearly power available at the top of either the breaker or disconnect, opening the breaker or disconnect allows one to work on everything from the load side down. Even in units which are wired directly to the bus (not stabbed in), the wiring is clearly visible but not any more hazardous than an energized extension cord. Second with regards to arc flash, there has to be an interaction which can be reasonably expected to cause an arcing fault. We are talking about credible hazards here, not incredible things. Operating breakers, disconnects, etc., does not count, unless the breaker just recently tripped. Neither does a lot of other tasks. As an example a meter built to current standards doesn't have enough exposed metal to cause an arcing fault (not enough to bridge phases or phase-to-ground). So once we get down to essentially those tasks that involve making circuit changes (which is pretty much the only ones that apply) then we need justification. So either the equipment has to be designed in such a way that you can't de-energize it. And this would be limited for instance to light poles next to highways where they pull the fuses live. Or because of the greater hazard rule. This rule can be applied for instance when cutting off life support equipment, emergency equipment, lighting equipment, etc. But if the only reason for exercising the rule is to minimize production loss, you are out of luck, as per OSHA.

OSHA's standards by the way are reasonable. It is unreasonable to require any theoretical arc flash risk to be considered, just as it is with any other hazard. As an example the current national average electrical injury rate is about 0.1-0.2 per 10,000 workers per year. That is no different than pretty much any other work place risk. If we were to treat electrical equipment as inherently dangerous (instead of inherently not dangerous) then we'd pretty much have to stop all work and keep workers at home because the risk of commuting to work, even while walking, is far greater. Although this threshold varies by industry to a great deal with fishing and logging coming out at around 1 in 1,000 workers per year vs. electrical work at more than 10 times less risk, even when lumping in construction and overhead line work (which alone accounts for nearly half of all electrical injuries), as long as there are not ELEVATED risks for the task, this is what OSHA considers taking reasonable precautions.

As an example I've worked in one plant that declared that they will not do "ANY" energized work. I don't even know what that means. Properly de-energizing equipment IS energized work. There's no getting around it. The second example decided to not perform maintenance and just declare all equipment inherently hazardous and throw on the PPE for everything. Again we get into the daunting task of writing an energized work permit for everything at which point, why bother doing work de-energized if everything requires a permit as if it is energized? This has even gotten as silly as one power plant that painted red lines on the floor at the limited approach boundaries and required anyone crossing it to wear arc flash PPE even when the equipment wasn't even being worked on (just walking by).

70E by the way is argued to death by committees of engineers. Remember those 20 different arguments? Any and all changes are subjected to scrutiny considering not only academic concerns but also practicality. If you are seeing something in the Code that seems to imply writing hundreds of permits, then you are probably misinterpreting it. Any time a change triggers such a crazy situation, it is very likely that it will get spotted early on. And since there's nothing saying you must adopt the latest version if it doesn't make sense, don't do it.

As a case in point of historical note, the first version of 70E that went on notice about arc flash is arguably the 2000 edition. That version was terrible and not ready for implementation on a wide scale. In 2002, NEC referenced it first and required arc flash labels for the first time. This immediately brought wide criticism to 70E and resulted in the vastly improved 2004 edition. 2007 got incrementally better. Many expected arc flash to get dropped from NEC and thus be relegated to a purely voluntary standard but it survived into the 2005 edition. So most companies started to get serious about that time and when the first citations were issued by OSHA to a major automotive company in 2006, this sealed the deal. Personally I looked at the 2000 edition (in 2002) and came to the same conclusions but got more serious about it in 2005 when it didn't go away.


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 Post subject: Re: Are provisions in earlier editions valid until rescinded
PostPosted: Mon Dec 28, 2015 9:17 am 
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Paul,
Thanks, I can see you put a lot of effort into your response and it helped much.

With comments to NEC 70 being adopted by the State - there are political ramifications as well as just construction ramifications when a State adopts the NEC into code. THE NFPA requirement for 'arc fault' breakers in 2011 had an economic impact on the added cost of construction for a home. Numbers between $500 to $1500 of additional cost were ventured. Though not extreme, this incremental amount would displace a percent of citizens from qualifying for a home loan. States are then left to decide which benefit; arc flash breakers or home ownership, serves the greater good of the population. The State could either adopt the code with exception, or unless it felt there was justification, just stay with the last adopted code until they felt change was warranted. NFPA is not necessarily concerned with 'best overall benefit' to the population - just to improved safety at any cost. Arc Fault breakers in 2011 were not really ready for the market place but NFPA pushed it forward, and some States balked. 70E has never been adopted as code by the States so it gets less resistance when it changes or increases burdens as it is more of an operational cost than a construction cost, although it could be both.

The reason we, as a company, would need to either have the standing permit, or write 500 permits, is because of the way we look at 'exposed energized parts'. We are MCC bucket extensive and if you need to change a fuse in a bucket, merely throwing the disconnect does not completely remove all energized parts. The stab and wires leading to the line side of the disconnet switch remain energized unless the entire MCC is de-energized. Would changing fuses with the disconnect open be likely to cause an arc flash? Probably not. So maybe we have to re-evaluate how we judge guarded parts. The same may be true with performing amprobe measurements in a panelboard, as long as we leave the deadfront on, we are not likely to cause an arc.

So in 2009 the NFPA board recognizes that it is 'infeasible' to shutdown a continuous process to service one instrument, But today the same action is feasible and mandatory. Like the State adopting the NEC, I am reluctant to agree that the social economic benefit does not outweigh the risk. Not being cavalier, but on a 208/120 NQ panelboard with 1.5cals, is the risk of adding a snap in circuit breaker as severe, as losing $100K in production.
How many members of the NFPA board are licensed electricians? I know fifty electricians, and all of them will confess to installing a snap in single pole breaker in a 208/120 panelboard without risk, or even concern, of severe injury. I'm not saying there shouldn't be limits, but I am saying this guideline would be better accepted if it took real world into account. The 2009 reference to the continuous process was a good reference that benefited manufacturing and had consideration for real world economic realities. Do mechanics work on car engines while they are running? Have they ever been cut by the spinning radiator fan, or burned by the exhaust manifold? There is risk that should be tolerated, as long as proper training and awareness is present to avoid injury resulting from that risk. NFPA is now saying that there is no justification for live work other than that which results in a greater life safety risk. Under this standard you can't even do a life work permit for the snap in breaker unless the panelboard supports some other life safety activity, even if the financial burden is extreme while the actual risk is minor. Unfortunately, there is no advocacy for a best fit approach, where risk and cost could be mutually accessed - like we do in real life hazard analysis reviews.

In any case, your response was excellent, and greatly appreciated.


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 Post subject: Re: Are provisions in earlier editions valid until rescinded
PostPosted: Mon Dec 28, 2015 1:48 pm 
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haze10 wrote:
The reason we, as a company, would need to either have the standing permit, or write 500 permits, is because of the way we look at 'exposed energized parts'. We are MCC bucket extensive and if you need to change a fuse in a bucket, merely throwing the disconnect does not completely remove all energized parts. The stab and wires leading to the line side of the disconnet switch remain energized unless the entire MCC is de-energized. Would changing fuses with the disconnect open be likely to cause an arc flash? Probably not. So maybe we have to re-evaluate how we judge guarded parts. The same may be true with performing amprobe measurements in a panelboard, as long as we leave the deadfront on, we are not likely to cause an arc.
Quote:

There are two clauses. A limited approach boundary does not exist when there are no exposed parts. Exposed is used in a limited sense. That is contact (or approach) must happen inadvertently and not intentionally. So with most bolt-on circuit breakers for instance where the energized lugs are clearly visible, they are also recessed so far that the only way for contact to occur is to purposely stick a conductive object into the hole. If no parts are exposed, then the approach boundaries simply do not exist. The flaw here is with low voltage (<=150 V) equipment. The approach boundaries are to "avoid contact", except for the limited approach boundary which is what triggers the "energized work" rule. As an example of where this causes problems, low voltage (120 V) lighting panels and even buttons and pilot lights wired on the doors of many panels are considered exposed and even though the restricted approach boundary is to avoid contact, it triggers a 3'6" boundary. The only way out of this quandry is to recognize the illogic of it and adopt a local exception.

Second with regards to tasks which can cause an arc flash, again this is of course "inadvertent" contact but prior to 2015 edition the only guidance was to refer to the task tables. The task tables in turn gave NO indication as to which tasks caused arcing faults and which don't. And if there was no arc flash hazard or in other words, the likelihood of a hazard was extremely low, the tables did not provide any indication of this except that for instance the tables for medium voltage switchgear gave a lower H/RC rating without any explanation as to what it means. This situation was of course ridiculous because if there is no arc flash hazard then H/RC does not apply at all and the correct PPE requirement would be "none" rather than a lower rating. In the 2015 edition, this interpretation is partially fixed. There is now a risk table which considers whether an arc flash hazard exists at all or not (based on task) followed by equipment and PPE tables. You "can't use" the tables if you've done an incident energy analysis by strict Code interpretation and are forced to develop your own task tables but there's nothing stopping you from simply adopting the risk table in 70E as the analysis. The drafts for 70E-2018 specifically allow for this exact approach.

Quote:
So in 2009 the NFPA board recognizes that it is 'infeasible' to shutdown a continuous process to service one instrument, But today the same action is feasible and mandatory. Like the State adopting the NEC, I am reluctant to agree that the social economic benefit does not outweigh the risk. Not being cavalier, but on a 208/120 NQ panelboard with 1.5cals, is the risk of adding a snap in circuit breaker as severe, as losing $100K in production.


That wasn't a 2009 rule. That has existed since the 1990's. Virtually the exact same wording is in OSHA 1910.3xx, which in turn adopted the wording from an early version of NFPA 70E! And that exact informational note has been widely misinterpreted incorrectly.

https://www.osha.gov/pls/oshaweb/owadis ... p_id=25559

In the above letter to OSHA a manufacturer described your exact same concern. OSHA's response was also similarly very clear. "It appears that your panel is not part of a "continuous industrial process." The term "continuous industrial process" was derived from its use in the National Electrical Code (NEC). In the NEC "continuous industrial process" is used in the context of situations where the orderly shut down of integrated processes and equipment would introduce additional or increased hazards.1 Therefore, to qualify for the exception found in Note 2 of ┬ž1910.333(a)(1), the employer must, on a case-by-case basis, determine if the orderly shutdown of the related equipment (including the panel) and processes would introduce additional or increased hazards. If so, then the employer may perform the work using the electrical safe work practices found in ┬ž┬ž1910.331-1910.335, including, but not limited to, insulated tools, shields, barrier, and personal protective equipment. If the orderly shutdown of the related equipment and processes would not introduce additional or increased hazards, but merely alter or interrupt production, then the de-energization of the equipment would be considered feasible, and the exception found in Note 2 of ┬ž1910.333(a)(1) would not apply. Based on the limited information you provided, it does not appear that de-energization of the panel in question would introduce additional or increased hazards. "

Quote:
How many members of the NFPA board are licensed electricians? I know fifty electricians, and all of them will confess to installing a snap in single pole breaker in a 208/120 panelboard without risk, or even concern, of severe injury. I'm not saying there shouldn't be limits, but I am saying this guideline would be better accepted if it took real world into account.


I don't know the exact number but even if they're not, several board members clearly have the experience you are talking about. In addition IBEW leaders routinely make public comments on changes and more than once their issues are accepted rather than rejected.

You are articulating two of the inherent limitations of humans when it comes to evaluating risk. The first is that we are creatures of habit. If we do something incorrectly and we receive negative feedback (pain, injury) then we conclude that this is risky and we stop doing it. If however we do something incorrectly and nothing bad happens, then the conclusion is that for whatever reason, it's safe to do. We continue to do the same activity, no matter how unsafely, over and over again until it becomes habit, even if we are instructed differently, because experience tells us something different. Activities with low likelihood of injury are inherently troublesome in this regard.

The second problem is that we have an inherent difficulty judging events that have likelihoods less than around 1%. We just can't wrap our heads around something that may only occur once in 1000 times or even more infrequently. The "threshold" for major injuries that cause hospitalization or death is generally around 1 event per 100,000 workers per year, and that seems to be close to the standard that 70E is based on, and that's the current likelihood of injury due to arc flash in the United States. So when you ask 100,000 current or former electricians and none have had a major injury or fatality, then you're on the right track. 50 or 100 is just way too small of a sample size. A better way would be to ask if it's even possible. Two electricians in Georgia in 2009 were working on a temporary power panel while energized. One was killed and one was hospitalized when an arc flash occurred. This is documented by OSHA. So there is evidence that under the right circumstances arc flash injuries from lighting panels are at least possible. The question of course is which tasks entail that much risk. If the task can bridge phase-to-phase, then this meets the requirements. An example of where it can't happen is with current design meter probes with the probe tip covers in place where exposed metal is less than the phase-to-phase or phase-to-ground distance. An example of where it can (and has) happened is with draw-out switchgear breakers where the stab folds over while racking it in. Sorry that I can't give a similar example for your situation, so you may be on to something here.

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The 2009 reference to the continuous process was a good reference that benefited manufacturing and had consideration for real world economic realities. Do mechanics work on car engines while they are running? Have they ever been cut by the spinning radiator fan, or burned by the exhaust manifold? There is risk that should be tolerated, as long as proper training and awareness is present to avoid injury resulting from that risk. NFPA is now saying that there is no justification for live work other than that which results in a greater life safety risk. Under this standard you can't even do a life work permit for the snap in breaker unless the panelboard supports some other life safety activity, even if the financial burden is extreme while the actual risk is minor. Unfortunately, there is no advocacy for a best fit approach, where risk and cost could be mutually accessed - like we do in real life hazard analysis reviews.


Actually that's not what the standard says. As long as a greater hazard exists, then it is an acceptable risk. And this is not 70E's standard. In fact that's not the direction that MOST safety standards are tending towards today. The rule is going slowly towards comparable risk. So when comparing say mechanics to electricians, we need to look first at the severity of the injury (don't treat first aid cases the same as fatalities) and second at the likelihood of injury, and insure that we are treating things on an equal basis with regards to outcomes and likelihoods. This is the approach taken with moving machinery hazards such as IEC 61508, IEC 61511, ANSI TR3, and ANSI RIA. This is as opposed to a plethora of prescriptive absolute standards which more or less "encode" the risk/severity tolerance directly into the rule without regard for situational-dependent requirements.

Fortunately 70E has always allowed for this comparative risk approach as has OSHA (risk assessments), but it's buried inside the "arc flash hazard" definition as of every edition up to 2012 and they more or less just beat around the bush in the Code. As of 2015 it is made much more explicit and goes a long ways but guidance is still a bit weak. And don't bother with Annex F...it is crap. In the drafts for the 2018 edition they are taking another direction and interpreting risk assessments as pre-task planning and more or less leaving it up to the true end users (electricians) but hopefully somewhere along the way we can get there.

And finally, glad you noticed that there is something "different" about electrical hazards because there is. Electrical hazards account for less than 1% of injuries as a whole. This fact is one of the fundamental reasons why many agencies simply don't even bother worrying about it when a much bigger impact can be had by addressing slips, trips, and falls for instance. BUT electrical injuries are the 4th leading cause of fatalities and major injuries. It is very easy to understand why. There is almost no such thing as shock or arc flash injuries which do not cause hospitalization. You can't compare moving equipment injuries to electrical injuries because there are no "bumps and bruises". And this is why electrical hazards are treated as if they are life-and-death scenarios, because they are.

In a large company of say 10,000 employees, we can expect only one electrical injury every 10 years on average. But that one injury will require extensive hospitalization or a funeral. So the vast majority of electricians may NEVER be injured or even have anyone on the same crew that is injured in their entire careers due to an electrical cause. There are no "knuckle busters" which can trigger accident investigations and generally aid in locating and weeding out poor work practices. Thus the approach required for electrical work is completely different from the approach needed for mechanics.

Finally, economics does play a role as does injuries. Ultimately we have to concern ourselves with all of these aspects as well as political ones. Economics and politics are concerns but not the only ones. Practicality is another one. Year after year public inputs were made to 70E to stick a rule in there stating that "just walking by" was not an electrical hazard. They were all rejected but "accepted in principle" because although the general concept was correct, getting the wording right was the issue. As of the 2015 edition there is an overriding concern about doors being "closed and latched" when in fact that's not a necessary nor a sufficient limitation on arc flash incidents. The issue is removing exposed, energized parts. To a secondary degree there is also a belief that closed doors provide some protection against arc flash when in fact the research shows that the closed door does little more than add a projectile. Perhaps this will get fixed in the 2018 edition.

What is missing from 70E (actually the entire NFPA process) but exists in legal texts is that frequently the logic, justification, and history behind the changes are incorporated into notes attached to each passage. We don't get that with the NFPA process and finding it is challenging.


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 Post subject: Re: Are provisions in earlier editions valid until rescinded
PostPosted: Mon Dec 28, 2015 2:34 pm 
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Paul,
Very much appreciate your response. You are well versed in the reference materials which I lack and rely solely on Art 130.
Your knowledge and objectivity is impressive.
thank you.


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 Post subject: Re: Are provisions in earlier editions valid until rescinded
PostPosted: Thu Dec 31, 2015 7:10 pm 
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When you live out in "multijursidiction land", you learn a lot about the underpinnings of things strictly because everyone uses slightly different interpretations, terminology, and so forth. We basically all agree on the major details but there are all kinds of little nuances with the minor details.

If you want to learn a little more yourself, start with what you have access to and frankly what is far more relevant than 70E. OSHA trumps 70E in the U.S., except for about a half dozen other jurisdictions (aeronautical, military, mining, maritime). So without getting too deeply into those...lets get into the wacky world of OSHA by itself.

For a standard industrial answer without spending a lot of money and time on things that don't necessarily relate to what you are doing, I suggest you read OSHA 1910, Subchapter S to begin with. This is very revealing and unlike 70E, it is regulation in the U.S. Use th online version because it also gives links to the letters of intrepretation. What you will quickly recognize is that it's essentially an abbreviated version of NEC and 70E but there are some major differences to recognize. For the most part 70E and NEC are careful to work "with" OSHA but the two are not always exactly identical. Some issues to notice are the order of operations (de-energizing, applying locks, grounding, testing for absence of voltage, "try"), and who must do each operation (qualified or unqualified), and also when the greater hazard rule can be applied (see especially the letters of interpretation).

If you have more time, spend time understanding GFCI's and when they are or are not required. Again a letter of interpretation really helps here.

If you have more time, pay attention to Subchapter J (general LOTO) and how it relates to Subchapter S which includes it's own LOTO. Guess what? They are very different and most companies miss how they mesh together, either incorrectly applying only one or the other. Also read up on Subchapter O and how it relates back to Subchapter J (and again S) because this applies in certain cases to energized work such as when you are checking panel meters and/or making changes or adjustments (programming) to equipment.

Still more time? Here's a fun one. There is no definition of "maintenance" vs. "construction" in OSHA but it makes a major difference. OSHA 1926 applies to construction while 1910 applies to maintenance. But what constitutes maintenance and what constitutes construction is not what most people think it is. 1910.4 "explains" the difference and again there are letters of interpretation which help/hinder this. Why it matters is because 1926 does not have an "energized work permit" rule and on top of that 1926 requires tagout but lockout is optional while 1910 requires lockout but tagout is optional. 1926 probably applies to most "startups" and a lot of "overhauls", "shutdowns", or "turnarounds".

Still more time? Read 1910 Subchapter R. This is for "generation, transmission, and distribution". It's not just for utilities and depending on how you define "distribution" (no guidance here) it could mean everything down to the level just above motor starters including many panelboards, switchgear, etc. And again, very different rules in fundamental ways. Their lockout procedure is again different with some slight differences and in some cases, actual locks are not required, and energized work permits are also not required.

This is all the case WITHOUT even getting into international rules from other countries or other codes such as IEEE or IEC.


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