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Thread: Ultra Thin Wafer Downlight & NEC 410

  1. #1
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    Ultra Thin Wafer Downlight & NEC 410

    Greetings all I have the following code questions regarding these wafer thin LED downlights that are becoming quite common
    AKA "rat traps" in remodels as well as new work:
    http://www.lithonia.com/commercial/wf4+downlight.html

    The manufacturer instructions state

    "4. Place remote driver box thru the cut-out hole. If remote driver
    box need to be attached, use provided keyhole fittings on the back of
    the box to hang it using round head screw (not included)."


    1) Does the 2017 NEC 410.30(A) require the "remote driver box" to be "securely supported" ?
    Per the definition of luminaire in art 100 "remote driver box" would be included as part of the "luminare".
    However I suppose just laying on top of a drywall ceiling is considered supported ?
    Especially in the context of a remodel where the cable is fished in and not secured within 12" of the box?

    2) Are these remote driver boxes required to be marked with volume in cubic inches?
    I have seen some of these boxes not marked with volume in cubic inches in violation of 314.16(A)(2).
    Especially since one is usually daisy chained to the next so now we have the "remote driver box" serving as a regular metal branch circuit junction box.
    Perhaps it can be argued that its not covered by article 314 regardless of that 410.20 seems to require compliance with 314.16 for fill.
    Perhaps this is a manufacturer oversight?

    Thanks in advance.
    I can post some photos of these if folks have not seen them.

  2. #2
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    IMO, the NEC allows the box to float since it is part of the luminaire.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  3. #3
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    Quote Originally Posted by Dennis Alwon View Post
    IMO, the NEC allows the box to float since it is part of the luminaire.
    Thank you. Even when its used as a Junction box to feed other luminaries ?

  4. #4
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    Quote Originally Posted by tortuga View Post
    Thank you. Even when its used as a Junction box to feed other luminaries ?

    If the box is rated for feed thru then I would say Yes, it can be floated. Mind you that an inspector can see this differently.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  5. #5
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    I think I would change my mind on this. If it is used as a feed thru then I think it needs to be mounted.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  6. #6
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    Quote Originally Posted by Dennis Alwon View Post
    I think I would change my mind on this. If it is used as a feed thru then I think it needs to be mounted.
    Think I agree. In addition I tend to think the intent of 410.30 is all parts of the luminaire to be securely supported. I have never seen a correctly installed a can light with a floating Jbox.
    The manufacturer offers a low voltage extension cable that can go up to 40' so the box could be mounted up in an attic and the low voltage class 2 part extended.

  7. #7
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    Half the time there is no attic above.

    The instructions of the Lithonia say to drive a screw into the nearby joist and hang the box from it. Done.

    A short drywall screw on a holding screwdriver makes this very easy to reach in drive the screw.

  8. #8
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    Quote Originally Posted by KaBoom! View Post
    Half the time there is no attic above.

    The instructions of the Lithonia say to drive a screw into the nearby joist and hang the box from it. Done.

    A short drywall screw on a holding screwdriver makes this very easy to reach in drive the screw.


    Works for me. I have been seeing lots of these unsupported.

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