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 Post subject: 130.7(C)(15)(A)(a) says PPE is required to walk by breakers
PostPosted: Thu Jan 29, 2015 2:13 pm 
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NFPA is now telling us that if all I want to do is walk by a breaker, I have to suit up to the level of PPE specified if that breaker is not maintained to the manufacture's specifications.

This is a HUGE burden for entities with large amounts of breakers because the level of additional work required to maintain per manufacturers specs is not practical. Also, requiring all personnel to suit up every time they walk by the breaker is not practical either.

We struggled with the decision whether or not to include it into our safety standard. We lean towards not including it and believe that the standard should be taken with a grain of salt. The chance of a breaker malfunction occurring at the exact time someone walks by is so unlikely that it is not worth the tremendous additional amount of work to either wear PPE or maintain breakers to manufacturers spec - especially when our breakers are maintained at least to some degree.

???What stance has your company taken???

For reference, NFPA 70E 2015, 130.7(C)(15)(A)(a), says for the task "normal operation of a circuit breaker, switch, contactor, or starter" arc flash PPE is required with one or more of the following:
The equipment is not properly installed
The equipment is not properly maintained
Equipment doors are open or not secured
Equipment covers are off or not secured
There is evidence of impending failure


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Fri Jan 30, 2015 5:55 am 
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Josiah Halverson wrote:
NFPA is now telling us that if all I want to do is walk by a breaker, I have to suit up to the level of PPE specified if that breaker is not maintained to the manufacture's specifications.

This is a HUGE burden for entities with large amounts of breakers because the level of additional work required to maintain per manufacturers specs is not practical. Also, requiring all personnel to suit up every time they walk by the breaker is not practical either.

We struggled with the decision whether or not to include it into our safety standard. We lean towards not including it and believe that the standard should be taken with a grain of salt. The chance of a breaker malfunction occurring at the exact time someone walks by is so unlikely that it is not worth the tremendous additional amount of work to either wear PPE or maintain breakers to manufacturers spec - especially when our breakers are maintained at least to some degree.

???What stance has your company taken???

For reference, NFPA 70E 2015, 130.7(C)(15)(A)(a), says for the task "normal operation of a circuit breaker, switch, contactor, or starter" arc flash PPE is required with one or more of the following:
The equipment is not properly installed
The equipment is not properly maintained
Equipment doors are open or not secured
Equipment covers are off or not secured
There is evidence of impending failure


Where are you coming up with "walk by breakers"? "Normal operation of a breaker" means changing the breaker from an open to closed position, or vice versa. It does not mean just being in proximity to a breaker that is energized.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Fri Jan 30, 2015 9:22 am 
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In addition to what was previously stated, I would agree that whatever the manufacturers put out as a standard for maintenance is poor at best. It is usually based on copying the same information over and over again and has a number of issues:
1. Molded case circuit breakers all reference NEMA AB-4 that I've checked on. NEMA AB-4 specifies exercising breakers, a quick visual inspection after a trip has occurred, and some deeper level testing ideas without lots of specifics. However only some breakers need to be tested (those that the incident energy study relies on). The testing frequency is not given. And dare I say it, there are a huge number of 15 and 20 A breakers in every residential installation that don't appear to be creating a major fire hazard so the requirements of NEMA AB-4 seem to not necessarily apply equally to all molded case breakers.
2. Testing for other types of breakers is even worse. EPRI (utility industry group) has collected lots of data on switchgear breakers. Many times the manufacturer fails to specify ALL lubrication points and many of the critical ones are missed. At this point at least for older switchgear breakers, I'd even suggest that EPRI is a vastly better standard to rely on than manufacturer information in particular. Manufacturers do not routinely send out "technical service bulletins" and updates to their manuals, unlike say automotive. So EPRI is probbaly your best bet, at least for older equipment.
3. NETA-MTS is a terrible standard. It has dozens of technical issues throughout it. It is written by a consortium of electrical testing companies whose goal is to line their own pockets. For instance despite research showing that it is not predictive and will actually damage older cabling, and the fact that the IEEE standard for "hi potting" specifically states that it should not be used, NETA-MTS specifies using it everyhwere. It also specifies using a torque wrench to check/retighten fasteners in spite of the fact that this shows a lack of understanding of simple fsatener technology. I could go on but you get the idea. NETA-MTS is referenced by 70E.
4. NFPA 70B is a little better than NETA-MTS but not by much. It is a maintenance standard though, not a safety standard. So about 75% of what it requires is not necessary to meet what 70E is specifying.
5. There is a lot of stuff in all of these that is there either because that's the way granddaddy did it or because one isolated case occurred with a type of equipment that is not even in use anymore, or where the older testing equipment had issues that the newer equipment does not have. Nothing was rever reviewed or deleted so the problem just continues to build on itself.

We do need a true safety bsed maintenance standard. But there is no such thing in any of the consensus safety standards out there. Manufacturers definitely cannot be relied upon to develop it on their own. So I'm at a loss as to what to do.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Mon Feb 02, 2015 5:50 am 
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In article 205 of 70E it states, "Electrical Equipment shall be maintained in accordance to manufacturers instructions or industry consensus standards."
I agree that manufacturers standards are very weak and do not address the level of maintanence needed to keep a breaker in good working order, but neither does doing nothing! And if you don't do anything, than you are liable if there is an incident.
I believe that the intent is for everyone to look at your electrical equipment and use all of the standards written as advice to develop your own maintenance plan that fits your needs. At our company we took the NFPA 70B and the NETA Standards and developed a good maintenance plan that operates and tests all circuit breakers, molded case or otherwise at regular intervals. We can at least show records that we are trying to keep our equipment clean and in good working order!
I think if you hide your head in the sand you are looking for a lot of trouble when you do have an incident!


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Mon Feb 02, 2015 12:41 pm 
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lovetacycle wrote:
In article 205 of 70E it states, "Electrical Equipment shall be maintained in accordance to manufacturers instructions or industry consensus standards."

I think if you hide your head in the sand you are looking for a lot of trouble when you do have an incident!


That was not my point. NFPA 70E refers to "properly maintained" many times but then cheats and basically states that someone else is responsible for creating a definition for "properly maintained". That is also why references to NFPA 70B and NETA MTS are in the informational notes, not in the standard.

My problem though is that quite literally, nobody defines "properly maintained" in any way that could be considered any kind of a standard. And I disagree strongly with the opinion that doing "something" is better than doing nothing. Take two good examples of where doing "something" in maintenance is actually WORSE than doing nothing at all. And these are both bad practices that are actually required in both NFPA 70B and NETA MTS:
1. Hi potting. Hi potting damages electrical cables by causing electrical treeing. That is why it is no longer recommended in the IEEE standards. Hi potting fails to detect anything more than a rough estimate of bulk contamination conditions, something that a visual inspection can also do without causing cable damage.
2. "Torque testing". Only about 10-25% of the force used to tighten most fasteners (bolts, screws) actually goes into tensioning the fastener. The rest is just overcoming friction. Thus torque isn't even a good measurement. Second, once the fastener is tightened, at a metallurgical/molecular level, the surfaces smooth out and the fastener relaxes, losing almost half of it's original tension. This effect happens within minutes/hours of the original tensioning. Coming back and putting a torque wrench on it will detect that all bolts and screws are always "loose" using the original tension specifications, even on the same job and the same day. And if the practice is to loosen and then retighten, this overstretches the fastener and weakens it, permanently. The result is that torque testing is not a good practice under any circumstance.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Thu Feb 05, 2015 2:28 pm 
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There are two issues- safety and liability. For both issues, it is incumbent upon the owner/employer to maintain the circuit breakers. I have seen circuit breakers fail and the arc is NOT a pretty sight.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Thu Feb 05, 2015 3:12 pm 
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For Maintenance of power circuit Breakers - check out US Department of Interior Bureau of Reclamation FIST 3-16. There's a whole series of standards free for download.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Mon Feb 09, 2015 8:26 am 
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I do agree with PaulEngr's comments on Hi Pot Testing. When I was working for a NETA company we quit doing Hi Pot testing with the exception of acceptance testing for cables and vacuum bottles. But I do not agree with your comments on Torquing. In all the years that I have been in the field performing maintenance on electrical equipment, I have never had fasteners loosen up on a regular basis. Sometimes when you go back on a piece of equipment the fasteners loosen up, but not everytime! The standards say that you need to test for tightness of the connections; you can use a torque wrench, infrared the connection, or use a DLRO and measure resistance. I am an infrared thermographer but you can not get an accurate reading if the equipment is not loaded.
I have been involved in incident investigations now for several years and I promise one of the questions asked by the authority having jurisdiction during the investigation is, "How did you verify the connection was tightened correctly? And when was the last time it was completed, show me the maintenance records."


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Tue Feb 10, 2015 3:06 pm 
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http://www.boltscience.com/pages/quality.htm
http://www.askbob.aero/content/can-you- ... per-torque

I can find more and these are just internet references, not actual mechanical engineering information but the conclusions will be the same and the above do a much better job of explaining the gritty details. Torquing to spec with a torque wrench to begin with is not very accurate, and rechecking with a torque wrench is at best a wild shot in the dark.

We deal with this problem here because we have several pressure vessels where the size of the fasteners gets up into the 2-3" diameter range. At that point it's not even practical to use even a large hydraulic "wrench" to tighten a nut and considering that it's a chemical plant, OSHA/EPA/whoever will definitely insist that we know with certainty that the tightening was done right. The actual process is high tech and expensive and far more complicated than would ever be done for most electrical fasteners.

The basic problem here is overcoming the friction of the screw itself is where most of the torque "goes". The actual holding force is the only thing that is of concern but this can't be measured with something as simple as a torque wrench. Despite massive advances in the field of nondestructive testing over the last 20 years, the fact is that there is still an enormous amount of data that either can't be measured or can be measured but only at great expense. As a case in point, why don't you X-ray overhead lines to look for defects and voids and internal failures between the strands? Does this sound crazy? It may be but in certain high performance wire rope applications, the cost of actually doing this is far less than a failure and as a result as high tech as this sounds, some wire rope is actually X-ray'd every few years.

Hence the reason that testing tension with a torque wrench is the same as testing for a connection with a hi pot. It sounds great but the engineering and science behind it says that it is not an effective technique at all for measuring the thing that it is supposed to measure. And I agree that if you don't "load" it, IR testing won't work. This is exactly like low speed gearing...vibration monitoring works great with high speed gearing but is useless with low speed gearing. Just like how PD measurements are great in the world of 5 kV and above for monitoring for cable issues but useless for 2 kV and under cable.


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Wed Feb 25, 2015 1:33 pm 
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Voltrael wrote:
Josiah Halverson wrote:
NFPA is now telling us that if all I want to do is walk by a breaker, I have to suit up to the level of PPE specified if that breaker is not maintained to the manufacture's specifications.

This is a HUGE burden for entities with large amounts of breakers because the level of additional work required to maintain per manufacturers specs is not practical. Also, requiring all personnel to suit up every time they walk by the breaker is not practical either.

We struggled with the decision whether or not to include it into our safety standard. We lean towards not including it and believe that the standard should be taken with a grain of salt. The chance of a breaker malfunction occurring at the exact time someone walks by is so unlikely that it is not worth the tremendous additional amount of work to either wear PPE or maintain breakers to manufacturers spec - especially when our breakers are maintained at least to some degree.

???What stance has your company taken???

For reference, NFPA 70E 2015, 130.7(C)(15)(A)(a), says for the task "normal operation of a circuit breaker, switch, contactor, or starter" arc flash PPE is required with one or more of the following:
The equipment is not properly installed
The equipment is not properly maintained
Equipment doors are open or not secured
Equipment covers are off or not secured
There is evidence of impending failure


Where are you coming up with "walk by breakers"? "Normal operation of a breaker" means changing the breaker from an open to closed position, or vice versa. It does not mean just being in proximity to a breaker that is energized.


Voltrael,
I interpreted the standard to include the case where a person walks by (or is working near) the exact time the breaker automatically operates. I think we can agree that breaker operation includes both manual and automatic operation. No?
-Josiah-


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Wed Feb 25, 2015 1:37 pm 
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"Sparks Level" is a title automatically assigned by the board.

I believe NFPA only intends the standard for manual operation of the breaker. While it is certainly conceivable that an arc flash could occur by an automatic (i.e. remote) operation of the breaker, that possibility, I believe goes beyond the code.

I actually toyed with the idea of putting up signs and possibly warning lights/sirens next to some switchgear breakers that were accessible by the general public (not in a locked room). But I wasn't doing it because I felt code required it.


Josiah Halverson wrote:
Voltrael wrote:
Josiah Halverson wrote:
NFPA is now telling us that if all I want to do is walk by a breaker, I have to suit up to the level of PPE specified if that breaker is not maintained to the manufacture's specifications.

This is a HUGE burden for entities with large amounts of breakers because the level of additional work required to maintain per manufacturers specs is not practical. Also, requiring all personnel to suit up every time they walk by the breaker is not practical either.

We struggled with the decision whether or not to include it into our safety standard. We lean towards not including it and believe that the standard should be taken with a grain of salt. The chance of a breaker malfunction occurring at the exact time someone walks by is so unlikely that it is not worth the tremendous additional amount of work to either wear PPE or maintain breakers to manufacturers spec - especially when our breakers are maintained at least to some degree.

???What stance has your company taken???

For reference, NFPA 70E 2015, 130.7(C)(15)(A)(a), says for the task "normal operation of a circuit breaker, switch, contactor, or starter" arc flash PPE is required with one or more of the following:
The equipment is not properly installed
The equipment is not properly maintained
Equipment doors are open or not secured
Equipment covers are off or not secured
There is evidence of impending failure


Where are you coming up with "walk by breakers"? "Normal operation of a breaker" means changing the breaker from an open to closed position, or vice versa. It does not mean just being in proximity to a breaker that is energized.


Sparks Level,
I interpreted the standard to include the case where a person walks by (or is working near) the exact time the breaker automatically operates. I think we can agree that breaker operation includes both manual and automatic operation. No?
-Josiah-


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 Post subject: Re: 130.7(C)(15)(A)(a) says PPE is required to walk by break
PostPosted: Fri Feb 27, 2015 6:50 am 
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I guess my pet peeve with "properly maintained" is this:

There are a SMALL assortment of predictive maintenance tasks. These include visual inspections, UV inspections, IR inspections, acoustic inspections, vibrations, magnetic particles, milliohm testing, insulation resistance, turns ratio, X-ray testing, and more recently MCSA and PD testing have been touted for electrical, never mind all the offline tests such as circuit breaker testing, or tasks that are outright "life extension" such as lubrication and cleaning tasks.

However one question that does not get asked and is a huge problem with the "predictive" testing: which ones are actually non-destructive, and which ones are actually predictive in nature.

Take for example the ubuitous insulation resistance test. If it is done correctly (ie, follow IEEE standard 43 which means the instrument needs a constant voltage output and has to be applied for a consistent period of time (1 minute), not exceeding equipment rated voltage, and the results have to be temperature corrected), it is a good indication of the degree of conamination of the equipment. With potentially failed motors it generally detects about 80% of motor failures (mostly because it picks up on damaged insualtion). However:
1. A "negative" result on a motor test is basically a "unknown" result. It does not mean the motor is good, just not becessarily bad. You would not believe how many electricians do NOT know this.
2. There is no evidence that it gives a measurement of the insulation condition over time. All it measures is the amount of contamination. IEEE Standard 43 is pretty clear on this point.
3. It is not predictive in nature. Since it does not measure insulation condition on "good" insulation, if a megger test is "good" today, it can be bad tomorrow.

NETA MTS talks about megger tests like they are predictive. Similarly, hi pot testing is touted as "predictive". It is not only not any more predictive than the megger test, it is actually destructive on certain types of cables and can induce failures that may not occur for a couple weeks. See IEEE standard 400 and several other sources for details. Yet the various predictive maintenance literature still recommends it as a good test. And the PD folks aren't any better. Not to name names but a certain company does offline PD testing. They claim that their test does not do damage "like" hi potting. This is partly true. But they use a VLF to generate the voltage so it is not as destructive as the hi pot test (see again, the IEEE standard for this stuff, 400), but "less" destructive. I'm not exactly sure how a test touted as predictive, nondestructive testing is acceptable when it is destructive at all.

Another example is IR inspections. These show hot spots where conductors (not insulation) have failed. But often the amount of time where the hot spot is visible and failure occurs is a very narrow window, unlikely to be picked up by doing these things once a year. So although it is predictive, we need to know how much of a time window is needed in order to set the proper inspection frequency or it will miss critical events more than it will find them.

Finally, breaker testing is not predictive at all. What is is, is a failure finding activity. All the breaker tests out there are designed to detect breakers that have already failed in service but have not yet shown up because most breakers are rarely called to operate. So its a matter of dining hidden failures. What is needed here is a definition of an acceptable failure rate as well as the known failure rate of a breaker. Then the inspection frequency can be determined to probabilistically gurantee the acceptable failure rate. The inspection frequency may have to be tweaked over time if the failure rate is known to adjust it based on actual rates compared to book values. An exception would be for lubrication issues where the breaker has to be exercised or lubricated with some frequency. The trouble here is that again, very little if any test data actually exists. Frequently it is destroyed because the first thing specificied in most breaker tests is to OPEN the breaker. A time-travel test would have to be done before the first opening attempt or any data on breaker exercising is automatically void.

This is the kind of stuff that is seriously missing from NFPA 70B and NETA MTS. There is no specific notion of an engineered approach to equipment mainteannce, nor anything other than conjecture on timing.


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