You are much more educated than I so I feel like a teenage stepping in the ring with Mike Tyson. It seems to me that the way I've seen you speak about classification that you feel any building being built needs to have a specialized person to classify or not classify every place in every building.
It comes off like some electricians saying a homeowner should not be allowed to change a receptacle because they don't own a torque screwdriver. Technically not NEC compliant (not using a torque screwdriver) but doubtful it will be a problem. I actually find it rather insulting that you believe an EC is not able to make the determination of whether or not there are enough conditions on site to warrant a classification. In the OP's site, if fuel oil transfer is the only thing going on in that area then the NEC tells us there is no need for classification. Taking your position to the extreme, I would need to call in a qualified person to determine if I have any "classified" areas on a room addition to my house.
I submit that since you are an expert in this field that you have succumb to " To the man who only has a hammer, everything he encounters begins to look like a nail" syndrom. I mean no disrespect or insults by my comments and acknowledge your superior education.
I’m not planning on printing this thread and using it in court. More just asking the question so I know what questions I should be asking. I agree that someone with a PE license should be the AHJ
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thanks guys
Oldsparky52, no offense taken at all.
I have said many times before, classifying a location is neither rocket science nor trivial, but it should be done by someone who knows what they are doing. That doesn't necessarily mean a PE (or AHJ)
Back when NEC Zones were introduced (technically 1996, effectively 1999) the NEC
did require a registered PE to classify for Zones. [1999 NEC Section 505-6(a)]. That is no longer an NEC requirement since well over half of the CMP at the time wouldn't be qualified (even those that were degreed engineers); however, some jurisdictions
do require a PE stamp (not necessarily electrical) on for all electrical area classification documents.
The fact is, a location may be classified simply by experience alone as noted in NFPA 497, 499, or API RP500; e.g., NFPA 497[2017], Section 5.6.4. Those documents also contain fairly exhaustive material on the full process of classifying more complex systems. NOTE: there's more to properly classifying a location than checking a few diagrams or tables.
I do appreciate LLSolutions offer to not use this thread in court; however, despite this site's disclaimers to the contrary, a responding licensed PE could still be held liable for erroneous answers. (They should know better) Several codes of professional ethics also come into play.
All that said, my original response (Post #2) still stands: the classification, if any, should be properly documented, temporary or not.
EDIT ADD: The real OP question was if an overhead solution was permitted. The answer is yes in Class I, Division 2.