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Thread: Pancake Box Fill

  1. #1
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    Pancake Box Fill

    Got a 4/0 pancake at 5.8 cu in with one 12-2 Romex going into it. If all conductors are counted the wire cu in is 6.75 (2.25x3 conductors). Too much wire for box. I've been told by another electrician that the ground conductor does not get counted, therefore cu in is good. I can't find any code that says I don't have to count ground wire into cu in Calc. Any thoughts/known code on omitting ground wire? Thanks.

  2. #2
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    Quote Originally Posted by Vegassparky123 View Post
    Got a 4/0 pancake at 5.8 cu in with one 12-2 Romex going into it. If all conductors are counted the wire cu in is 6.75 (2.25x3 conductors). Too much wire for box. I've been told by another electrician that the ground conductor does not get counted, therefore cu in is good. I can't find any code that says I don't have to count ground wire into cu in Calc. Any thoughts/known code on omitting ground wire? Thanks.
    The guy is thinking of the exception in 314.16(B)(1). It does not apply here.

    (B)(5) addresses EGCs.
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #3
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    Quote Originally Posted by Vegassparky123 View Post
    Got a 4/0 pancake at 5.8 cu in with one 12-2 Romex going into it. If all conductors are counted the wire cu in is 6.75 (2.25x3 conductors). Too much wire for box. I've been told by another electrician that the ground conductor does not get counted, therefore cu in is good. I can't find any code that says I don't have to count ground wire into cu in Calc. Any thoughts/known code on omitting ground wire? Thanks.
    You do get to count the cubic inches from the light fixture cover.
    If you go and decide to dance with a gorilla the dance ain't over till the gorilla decides it's over.

  4. #4
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    Quote Originally Posted by ActionDave View Post
    You do get to count the cubic inches from the light fixture cover.
    If marked. 314.16(A).

    (A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections and, where used, the space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with their volume or are made from boxes the di- mensions of which are listed in Table 314.16(A).

    If unmarked-we do it anyways.
    "Electricity is really just organized lightning." George Carlin


    Derek

  5. #5
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    I've never seen a marked canopy. We just use 12/2 AC cable MC-ap.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  6. #6
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    I have never been asked for a marked canopy.
    If you go and decide to dance with a gorilla the dance ain't over till the gorilla decides it's over.

  7. #7
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    Quote Originally Posted by infinity View Post
    I've never seen a marked canopy.
    I have never even looked, but then I doubt that have installed a dozen pancake boxes in total.

    When I have I needed to, I just guesstimated canopy volume.

    Quote Originally Posted by ActionDave View Post
    I have never been asked for a marked canopy.
    Most inspectors prolly care as little as we do.
    "Electricity is really just organized lightning." George Carlin


    Derek

  8. #8
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    Quote Originally Posted by jumper View Post



    Most inspectors prolly care as little as we do.
    Now that I think of it, I dont recall EVER having an inspector look at my box fills. I still comply 98% of the time
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  9. #9
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    Quote Originally Posted by electrofelon View Post
    I still comply 98% of the time
    Maybe. You do resi and use carlton plastic boxes or similar?

    If yes, do you count the internal clamps for box fill? Or do assume the manufacturer includes the clamps for the marked volume or number of conductors?
    "Electricity is really just organized lightning." George Carlin


    Derek

  10. #10
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    Quote Originally Posted by jumper View Post
    Maybe. You do resi and use carlton plastic boxes or similar?

    If yes, do you count the internal clamps for box fill? Or do assume the manufacturer includes the clamps for the marked volume or number of conductors?
    I like the allied molded boxes the best, but have to resort to the blue bombers frequently. There have been some discussions on the clamps in NM boxes and I thought the general consensus was that they dont count as clamps? I usually just look at the volume and do my own calc. I know they often have the number of conductors also molded in but just habit I guess I do my own calc.
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

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