2

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 5 conductors which would require 10 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, that would add another 2 conducters. 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)?

enter image description here

  • 1
    Avoid Amazon. Many of their listings come from a thing called Amazon Marketplace, which is cesspool of garbage from overseas. Worse, due to a loophole in import law, stuff direct shipped from China or drop-shipped from Amazon's fulfillment centers evade US safety law. This one has an ETL mark with file number (on the mains voltage part) which makes it unlikely to be a fake, but point is, you take your chances everytime. Do the instructions state cubic inches? I would expect ETL to require this as a condition of listing. – Harper Oct 19 at 19:12
  • They have a website unlike some Amazon sellers, but it is a huge variety of product and no technical resources whatsoever. The only PDFs on their site have to do with being resellers, orders or payment. Manufacturers don't behave that way, but importers do... – Harper Oct 19 at 19:24
  • Nope. Nothing in the instructions or printed on the box itself. Funny enough, I almost bought these lights from Home Depot, but didn't want to wait a week for shipping. Looking at the provided pictures and info guides, it looks like even Home Depot's brand suffers from the same problem. – Tim Bauman Oct 19 at 23:56
1

Bonus question: 334.5B is not a statutory waiver, it's to let you off the hook if the task is not easy, or if trying would risk mistakes (like trying to reach through a 6" hole with a staple gun). If it's easy, you gotta do it.

On your splices, the fill rules require:

  • 1 "wire" covers all grounds
  • 1 "wire" covers all cable clamps
  • 1 "wire" per actual wire brought in

So I count 6 wires. 14 AWG calls for 2.0 cubic inches per wire or 12ci. Since this is part of equipment, I would expect the provided wires would be included in the cubic inches the manufacturer states.

However I note a < $ 10/light price point. I also note their website is very marketing oriented, and has absolutely no technical sections, in the ordinary way a site like Eaton's or Lutron's would. On the other hand, the site is perfectly competent, with none of the teeth-clenching English mistakes typically seen in overseas "makers", so I don't know what to think.

  • Thanks for the clarification on 334.5B. Even within 12in of the box, it certainly wouldn't be easy. I'm not even certain it's possible for most of the lights, without opening up additional drywall. – Tim Bauman Oct 19 at 23:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.