Help with box volume/fill for junction box provided with LED recessed light

by Tim Bauman   Last Updated October 19, 2019 18:21 PM

I recently purchased and in the process of installing a series of 6 recessed lights. I've replace some lights in the past, but this is my first real electrical installation (i.e. novice alert).

I ended up going with these slim LEDs, as I don't have the clearance for normal or even shallow cans. However, after having a quick chat with a local inspector, he warned me that some of these newer lights don't come with junction boxes that are considered code compliant for pass through. In doing my best to stay to code, I'm attempting to measure the box volume and fill.

The available space in the j-box (I'm assuming I can't include the sealed portion), measures out as 3.75x1.75x1.25=~8.2 cubic inches. Right now, I have two 14.2 NM coming into the box (one to provide power, the other to relay to the next light). If I'm understanding things correctly, that alone counts as 7 conductors which would require 14 cu.in. This seems to mean that my inspector's warning was correct.

I'm not sure if I should include in the conductors count, the provided cables that lead into the sealed part of the j-box. If I did, then wouldn't that mean that the box is too small even for even a single 14.2 NM cable?!

My main question is if I'm calculating things correctly here, and if so, what are my options at this point to remain code compliant?

Bonus question. Per 334.30(B), I've found that I do not have to staple my wiring every 4.5ft because it is existing construction. Does this also imply that I do not need to staple it from 12in from the box (assuming it's clamped to the box)?

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