How much authority does the AHJ have?/Temporary classification of areas

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Sparketta

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I have searched and searched, and it seems from what I have read in the code that the AHJ has a great deal of latitude for interpreting it. Are there limits to how much authority the AHJ has?

The hypothetical in my question deals with a location that is similar to a military base, with the AHJ being appointed to the position. Because the AHJ is employed by the agency that has overall control of the complex, it would seem that there exists a conflict of interests. The AHJ is persuaded to approve certain things, mainly in this case it pertains to portable plug-in or battery powered equipment used in Class 1 Div 2 areas, because he is told that the items are necessary to the "mission" of his agency, and not based on any kind of testing or research. Can the AHJ make blanket approvals of such equipment in classified areas?

Next question, can areas be classified temporarily on the basis of the presence of flammable liquids and declassified the rest of the time? I understand that the NEC really is only concerned with electrical installations, and those should be compliant if the area is ever to be classified. But what about plug-in equipment and battery powered stuff? The NEC might not be concerned with these items, but OSHA is.

The types of locations I am referring to are buildings that sometimes hold vehicles or portions of vehicles with tanks that have flammable fuels in them. The systems are extremely secure due to the severe toxicity of the fuel and the fact that there are also tanks present on the vehicles holding oxidizer that will react violently with the fuel- they are hypergolic. There are many redundant features in order to contain the fuel and oxidizer at all times. Small leaks have occurred in the past but they are tiny, tiny leaks, on the order of only a few parts per million or billion, and the lower flammable limit of the fuel is 2.5% which equals 25,000 parts per million.

There are certain operations that are conducted, such as the changeout of valves, where there is slightly more potential for fuel vapors or liquid to be present, but still the potential is only to see a very small amount. The largest amount spilled in the past 25 to 30 years has been approximately one quart. These operations are conducted in full rubber suits with supplied air and there are inspections of the area conducted just prior by a fire inspector to ensure that everything is as it should be. These areas have been designated, perhaps incorrectly, as permanent classified (Class 1 Div 2) areas, and in some of the facilities portions of the wiring is not compliant. The way that this is "mitigated" is by opening the breakers to the non-compliant wiring and locking the circuits out prior to hazardous operations.

Is it just me or does it sound like 1) these areas should not be classified at all, and 2) that if they were truly classified areas that this is a completely unacceptable way to operate?

Any thoughts?
 
we have done some jobs which are sort of similar in that as far as class 1/div 1 they were non-conforming (read the first paragraph in 500 as to what sorts of things is/are not covered by class 1/div 1 in NEC. in our cases, the ahj had absolute authority. all we could do is cya with written documentation thru our chain of command. if life safety was an issue, we would bring it up, but collateral damage control was really all that was taken seriously - when you contract to be in harms way, that's where you are. if something goes seriously wrong, there's not much you can do but bend over and kiss it goodbye. hopefully you are getting paid enough to make it worth the risk.
 
Thanks, Nakulak. The installations in my "hypothetical" are not areas that are currently being wired, they are already permanent work areas and have been for decades. The work that is conducted in the areas is maintenance/processing of the vehicle I mentioned. I do not think that there is any significant danger from sparking equipment, rather that the areas are classified when they should not be. We weld on the vehicle regularly, so if sparks were a problem, I wouldn't think it would be safe to weld.

You are right about the part that if something goes wrong you can kiss it goodbye, but I would think that would fall under a catastrophic failure, which is not supposed to be a basis for classifying an area.
 
I've had an insurance adjuster tell me SEU was no longer UV protected because it was painted:roll: Sad thing is, you can't really argue with them if the HO wants to keep them. Even though I have had several laughs and cold ones out of the situation, the drop was replaced. It's one of those cases where you have to serve the HO, and just bite your tongue. I have never mentioned any names because I don't believe in slanderizing anyone, you just provide the service, and accept the bill:rolleyes:
 
It sounds to me like this hypothetical agency with its hypothectical building and its hypothetical vehicle(s) and fuel(s) would have you, hypothetically speaking, sign an NDA, which would prevent you from asking the question in the first place. ;)
 
jerm said:
It sounds to me like this hypothetical agency with its hypothectical building and its hypothetical vehicle(s) and fuel(s) would have you, hypothetically speaking, sign an NDA, which would prevent you from asking the question in the first place. ;)
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Ha ha, Jerm. No, there is no hypothetical NDA, I am just hypothetically trying to be discreet.
 
Theoretically, the NEC is an “Installation” Standard. See Section 90.2(A). Of course the use of mobile and portable equipment is occasionally mentioned – even is Article 501. This has been something of a quandary for CMP14. They are willing to describe the use of specific portable equipment, such as luminaires, but are reluctant to make general applications – because the NEC is an “installation” Standard.

Philosophically, if a location is properly classified, it retains the classification indefinitely until it is either temporarily suspended with a “hot-work” permit or formally reclassified. See Section 500.4(A). Of course, once an area has been classified, constuction shoulb be consistent with the classification.

I’ve read/reread the OP a few times. My personal opinion is that it probably doesn’t need to be classified at all if “… [t]he largest amount spilled in the past 25 to 30 years has been approximately one quart.” That, along with the other safety measures that seem to be in place, would make the installation a candidate for applying, NFPA 497, Section 5.5.4. :
5.5.4 When classifying buildings, careful evaluation of prior experience with the same or similar installations should be made. It is not enough to identify only a potential source of the combustible material within the building and proceed immediately to defining the extent of either the Class I, Division 1 or Division 2; or Class I, Zone 1 or Zone 2 classified areas. Where experience indicates that a particular design concept is sound, a more hazardous classification for similar installations may not be justified. Furthermore, it is conceivable that an area be reclassified from either Class I, Division 1 to Class I Division 2, or from Class I, Division 2 to unclassified, or from Class I, Zone 1 to Class I, Zone 2, or from Class I, Zone 2 to unclassified, based on experience.
[rba note: underline added]


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rbalex said:
Theoretically, the NEC is an ?Installation? Standard. See Section 90.2(A). Of course the use of mobile and portable equipment is occasionally mentioned ? even is Article 501. This has been something of a quandary for CMP14. They are willing to describe the use of specific portable equipment, such as luminaires, but are reluctant to make general applications ? because the NEC is an ?installation? Standard.

Philosophically, if a location is properly classified, it retains the classification indefinitely until it is either temporarily suspended with a ?hot-work? permit or formally reclassified. See Section 500.4(A). Of course, once an area has been classified, constuction shoulb be consistent with the classification.


I?ve read/reread the OP a few times. My personal opinion is that it probably doesn?t need to be classified at all if ?? [t]he largest amount spilled in the past 25 to 30 years has been approximately one quart.? That, along with the other safety measures that seem to be in place, would make the installation a candidate for applying, NFPA 497, Section 5.5.4. :
5.5.4 When classifying buildings, careful evaluation of prior experience with the same or similar installations should be made. It is not enough to identify only a potential source of the combustible material within the building and proceed immediately to defining the extent of either the Class I, Division 1 or Division 2; or Class I, Zone 1 or Zone 2 classified areas. Where experience indicates that a particular design concept is sound, a more hazardous classification for similar installations may not be justified. Furthermore, it is conceivable that an area be reclassified from either Class I, Division 1 to Class I Division 2, or from Class I, Division 2 to unclassified, or from Class I, Zone 1 to Class I, Zone 2, or from Class I, Zone 2 to unclassified, based on experience.
[rba note: underline added]



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I agree.

One suggestion would be if there is still concern, after all you suit up the operators WHEN deemed neccessary for the work about to be performed, I would add exhaust fans with louvers that would be triggered by the LEL. This would further justify not classfying the area.

This is not a Code requirement as 497 gives you pleanty of room to make a reasonable evaluation to call it or not to call it a hazardous area.
 
weressl said:
I agree.

One suggestion would be if there is still concern, after all you suit up the operators WHEN deemed neccessary for the work about to be performed, I would add exhaust fans with louvers that would be triggered by the LEL. This would further justify not classfying the area.

This is not a Code requirement as 497 gives you pleanty of room to make a reasonable evaluation to call it or not to call it a hazardous area.
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I agree with both of you, and had found the exact passage in the code that rbalex cited, which is one of the things that led me to think the area should be unclassified. The fan thing you described, weressl, is already in place. There are enormous fans in the ceiling, known as "hyper(golic) fans" for just such occasions. I believe they are triggered by the engineers on console that are conducting the operation, rather than the LEL, though, and would be used well before the LEL was approached, as a precaution. Aspirators connected to wet scrubbers are used as well to suck out the small amounts of vapors/liquid that escape in an operation. There is also a high volume water deluge system that could be activated to dilute the liquid in the event of a spill, though I doubt that on its own makes any difference in the classification.

Thanks for the great insight, rbalex and weressl- you guys are the experts! Now, I just have to convince the right people to get the areas declassified. I am trying to learn as much as I can about hazardous classified areas, and I have purchased the book that was recommended in another thread here, Electrical Installations in Hazardous Locations by Peter J. Schram and Mark W. Earley. I will be back to pick your brains more in the near future, I am sure.
 
rbalex said:
Philosophically, if a location is properly classified, it retains the classification indefinitely until it is either temporarily suspended with a “hot-work” permit or formally reclassified. See Section 500.4(A). Of course, once an area has been classified, constuction shoulb be consistent with the classification.
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Rbalex, I would take it that this means that it would not be acceptable to have a classified area delineated on a drawing with a note that says that the Class 1 Div 2 areas are only applicable when flammable liquids are present. That is what appears on the drawings of the areas I have described, and it just seems wrong. Could an AHJ say that it is okay to do that, though? Does the AHJ have to answer to anyone, or can they just approve anything they want, regardless of whether it meets the intent of the code?
 
That is my interpretation based the root classification definitions in Section 500.5 and the documentation requirements of 500.4(A). If the flammable liquids were known to be present, then it would be both Division 1 and 2.

Would they rewire the facility each time in preparation for the flammable to be introduced?

Since I believe the facility doesn?t actually need to be classified, the AHJ could probably get away with just about anything. However, I don?t see what they believe they are achieving.
 
IMO, such an installation is not a candidate for classification. It seems no different than your typical home garage. You night spill gasoline now and then while refilling your lawn mower, but thats no reason to classify the whole area.

As for the AHJ having "blanket" authority to do anything, in general that is true. In practice, what you are referring to is probably not truly the AHJ, but merely a representative thereof. he probably does not have authority to make such a decision, but can enforce existing decisions.

As for portable devices, the AHJ over code enforcement generally has no power to regulate the use of such devices. In practice, representative of the AHJ and the individual who does regulate the use of such devices may well be the same person.
 
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petersonra said:
IMO, such an installation is not a candidate for classification. It seems no different than your typical home garage. You night spill gasoline now and then while refilling your lawn mower, but thats no reason to classify the whole area.

As for the AHJ having "blanket" authority to do anything, in general that is true. In practice, what you are referring to is probably not truly the AHJ, but merely a representative thereof. he probably does not have authority to make such a decision, but can enforce existing decisions.

As for portable devices, the AHJ over code enforcement generally has no power to regulate the use of such devices. In practice, representative of the AHJ and the individual who does regulate the use of such devices may well be the same person.
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Yes, that is exactly it- the AHJ in this case does have authority to approve or disapprove usage of these devices in the area. It is a unique area that is rather autonomous with no public access. But the AHJ there is actually a named individual. There is not enough there to justify having any more than one person so they left it all in that one guy's hands, right or wrong.

I love the way you have put it with the garage analogy. That is perfect. But let me ask, do they generally classify aircraft hangars? Because it would seem that the same logic could apply (though aircraft fuel tanks are generally vented and have much greater potential for creating an ignitable mixture than the vehicle in my scenario). I have worked in a few hangars and there were no classified areas in them, but the places I worked were not compliant with other regulations, so it is conceivable that this could have been one of those they missed.
 
Aircraft hangars are routinely classified; in fact, there is an entire NEC Article (513) dedicated to them. As with most classifed locations, the entire set of conditions must be evaluated to do it properly.
 
rbalex said:
Aircraft hangars are routinely classified; in fact, there is an entire NEC Article (513) dedicated to them. As with most classifed locations, the entire set of conditions must be evaluated to do it properly.
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Per that article, areas around an aircraft are classified even when it is outdoors- that doesn't seem to go along with the NEC only being concerned with electrical installations, though, does it? Can you explain?
 
I suspect you are referencing Section 513.3(C); it should be interpreted in context of the Scope of the Article, Section 513.1: ?This article shall apply to buildings or structures ??
 
rbalex said:
I suspect you are referencing Section 513.3(C); it should be interpreted in context of the Scope of the Article, Section 513.1: ?This article shall apply to buildings or structures ??
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Thanks, rbalex. I don't have all of the code available here to me at home, so I had to go from what I saw on a drawing that referenced parts of it. I will look at that whole article at work tomorrow.

Thanks again for your expertise- I appreciate you taking the time to answer my questions.
 
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