I'm installing 3 LED shop lights in my basement workshop. I've already run new 12/2 NM-B wire to a few junctions and switches, per light. The attached picture is an example of the final splice I need to make.

The cables that come out of the product (both need powered) are quite short and so don't lend themselves to being pulled into a junction box. It may look like there's just enough slack to mount a junction box right on the joist in the picture, but not all of the lights are mounted such that their wires are that close to a joist.

The fluorescent shop lights I'm replacing simply pulled the 12/2 directly into the light enclosure, but these LED lights have no room for that.

Would this be an acceptable place to use the (Tyco, etc.) NM cable splices mentioned in the top answer here? If not, what's the best solution?

Thanks, == Matt

enter image description here

More pictures by request:

Full fixture without the diffuser/cover: enter image description here

Where the wiring exits the fixture: enter image description here

Instructions assume flush mounted junction box: enter image description here

  • 1
    Can you post an image of the inside of the fitting? Commented Dec 28, 2018 at 7:26
  • 1
    I think the NM-B is supposed to enter the fixture and the splice should be inside, you say there isn’t enough room for that, are you sure? Most light fixtures work that way.
    – Tyson
    Commented Dec 28, 2018 at 10:42
  • Did the fixtures come with instructions? Commented Dec 28, 2018 at 12:44
  • @Tyson To clarify, there would technically be room between the top of the fixture and the diffuser cover for splices, however, the cables are intentionally routed out of the fixture, and there's really no way to route anything back into it. Plus, anything inside the fixture would block the LEDs. The pictures I've added to the OP show what I mean.
    – mmseng
    Commented Dec 28, 2018 at 18:12
  • @SomeoneSomewhere Added pictures.
    – mmseng
    Commented Dec 28, 2018 at 18:12

2 Answers 2


What you want is a ceiling box that uses an old-work brace

If you have ever been in a hardware/home-improvement store and wondered why some of the boxes had what looked like a long metal brace attached to them, like so (picture for illustration only):

old work ceiling box w/ brace

wonder no further. That brace is meant to go between adjacent ceiling joists and support both the box and a fixture attached to the box, and the box can be adjusted to position it in the joist bay. The fixture itself then acts as the cover for the box, as per NEC 314.25 and 410.22.

(Trying to support a box using a lighting fixture would likely be seen as a NEC 314.23 violation -- there is no subsection of 314.23 that allows for that.)

  • Hmm, I see. That does sound like a secure solution. I'm having a hard time picturing what this would look like though. Assuming I was using a box like the one pictured, would the box be aligned as in the picture (where the cover would be vertical)? Or would it be intended to mimic a flush ceiling box, and the opening would point down, with the light acting as the cover (as in my picture of the instructions)? Or some other way?
    – mmseng
    Commented Dec 29, 2018 at 4:13
  • @mmseng -- see my edit Commented Dec 29, 2018 at 4:16
  • Just to be clear, the positioning and rotation of the box on the brace is presumably irrelevant, as long as the box is being supported by the brace, yes?
    – mmseng
    Commented Dec 29, 2018 at 20:28
  • @mmseng -- yeah, as long as the box opening faces down (so you can get at it by taking the fixture off) and the box is supported securely between the joists by the brace, you're fine Commented Dec 29, 2018 at 20:34
  • I guess what I was asking is, is it kosher for the box opening to face sideways, as long as the cables are properly entering through punch-outs on the sides (or top/bottom), and the box is then given a cover?
    – mmseng
    Commented Dec 29, 2018 at 21:55

I am not an electrician but ... you could use a gray plastic outdoor junction box and cover attached directly to the back of the fixture. First plan the location for 2 self-tapping screws into the fixture. Then drill a 7/8" hole in the back of the junction box. Attach the box with the pigtails coming through the drilled hole. No additional grommet is needed, just the one on the fixture. Use an approved entry for your 12/2 wire, do the splice and install the cover. That's what I would do. Hopefully the electricians would do something similar.

  • This is the right answer. Attach a box to the light fixture itself. There is plenty of length in the wires from the fixture to do that.
    – longneck
    Commented Dec 28, 2018 at 18:15
  • @JohnCanon Thanks. That sounds reasonable and doable. I'll keep it in mind for now.
    – mmseng
    Commented Dec 28, 2018 at 18:16
  • @mmseng -- unfortunately, this answer's proposal violates 314.23 insofar that none of those sections allow a luminaire to support a junction box that is not integral to the luminaire. Commented Dec 28, 2018 at 21:29

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