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Thread: An entire building class 1 division 2 location?

  1. #1

    An entire building class 1 division 2 location?

    I'm far from an expert on classified locations so I could use some help. I am bidding a job in MN. There is a note on the riser that reads that all wiring methods must conform with class 1 division 2 locations. The building has a shop, a warehouse, and some office space. I've been reading through code articles on hazardous locations....but I have questions:

    1. If the entire building is class 1, div 2 then would that mean that no seals are required because the conduits won't be entering into any non-classified locations?

    2. Do the fixtures need to be explosionproof?

    If the entire building is of this classification it seems to me that everything needs to be in rigid, even in the office space, with cord drops to each high bay fixture in the warehouse?

  2. #2
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    Can't imagine why they would classify a whole building like that with just a note on a drawing.

    Maybe they do not know what use the space will be put to and think it might be used to store materials that would require classifying the area.

    I am not sure that merely the potential of storing flammable materials in an area is a good reason to classify it as div 2.

    In any case, there is a boundary at some point where the div 2 area ends. If nothing else at the property line.

    How are they planning to use the office space if they are calling it div 2? You would not be able to use common office equipment there.

    In any case, seals are not part of any wiring method in chapter 3.
    Last edited by petersonra; 03-11-11 at 01:57 PM.
    Bob

  3. #3
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    Quote Originally Posted by petersonra View Post
    Can't imagine why they would classify a whole building like that with just a note on a drawing.

    Maybe they do not know what use the space will be put to and think it might be used to store materials that would require classifying the area.

    I am not sure that merely the potential of storing flammable materials in an area is a good reason to classify it as div 2.

    In any case, there is a boundary at some point where the div 2 area ends. If nothing else at the property line.

    How are they planning to use the office space if they are calling it div 2? You would not be able to use common office equipment there.

    In any case, seals are not part of any wiring method in chapter 3.
    The whole scenario just does not sound right.

    If you're(OP) not well versed in Classified location it would be wise of you to stay away from it, because not only you can loose substantial money on the job, but buying future liabilty if it is not properly inspected and approved.

  4. #4
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    When it isn’t necessary, a blanket Division 2 classification, “just to be safe,” is usually an exceptionally expensive proposition and often the result of a design from ignorance. (This is not to say the designer is stupid – they just weren’t quite sure what they were doing.)

    In a large outdoor installation there may be some justification for a blanket classification because it does indeed reduce the number of boundary seals required. However, where walls may present substantially different pressure differentials you really need to have a documented boundary. It only takes a differential of 6” of water and many HVAC systems can create that.

    RMC isn’t the only acceptable wiring method, See Section 501.10. Be careful when thinking about drop cords. See 501.130(B). Luminaries are not usually required to be explosionproof, but they will need to be specifically identified for Class, Division, Group and T-rating.
    "Bob"
    Robert B. Alexander, P.E.
    "I know that you believe you understand what you think the NEC says, but I am not sure you realize that what you read is not what it means." (Corollary to Charlie's Rule)

  5. #5
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    The note is phrased in such an odd way. It has stuck in my head.

    As I mentioned before, seals are not part of a wiring method. So IMO the note in and of itself does not require any seals at all.

    I am wondering if the designer is thinking that down the road it might become a div 2 area and using a wiring method suitable for a div 2 area might make it cheaper to convert to that use. I am not sure he is right, but maybe that is what he is thinking.

    He might also mean the whole thing is to be considered a div 2 area. But he did not say that.

    Maybe he is trying to be clever and is excluding PVC conduit without actually doing so explicitly.

    I would just ask him what he really wants. What he wrote is pretty open ended.
    Bob

  6. #6
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    Take a look at 500.5(A) (2008) and then you may want to get to whoever drew up the prints. You may get the job if the case is overstated to the classification of the building, and no one else notices, and bids high for the classification.

    You may want to submit a whole seperate alternative to the bid as a value engineered at the last minute. Bidding has gotten rotten out there, it may be the deciding factor is that others didn't perceive what you caught. Not saying anything till bid time may shoot competition out of the saddle. They may think you were a character for not notifying them earlier and letting everyone else capitalize on your consideration - Carpe diem.
    Don't let fear be your guide!

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