334.40(B) NM cable interconnector devices?

[bekahren]

It has been mentioned on this forum in the past that NM cable interconnector devices (like the Tyco romex splice kits or molex connectors) are often used to connect sections of modular housing wiring together. I am not convinced that NEC 334.40(B) permits that use if the interconnect device is then concealed in the wall of the modular home sections that are put together.

Per the IAEI article linked below, it is clearly Code-compliant to use connectors for repair of NM cable in existing buildings in concealed locations. However I would interpret 334.40(B) to only allow these connectors in "exposed cable wiring" in new construction, not concealed.

My question is whether this community of experienced electricians and inspectors believes it is Code-compliant to use these NM cable interconnects for new modular home construction where they will be concealed in the wall? What if the wall section was a removable panel - the connector is still concealed though?

Enter the Nonmetallic-Sheathed Cable Interconnector - IAEI Magazine

In the March-April 2014 issue, IAEI published an article entitled, “Maintaining a Safe and Reliable Electrical System. One of our members lodged his adamant concerns when he read the article....

iaeimagazine.org

 

[bekahren]

Perhaps I can answer my own question here. If a modular home is considered a Manufactured Building per Article 545, then 545.13 allows interconnections that are tested and listed to be concealed. TE Connectivity's NM sheathed cable device part number 1116377 is listed per UL File E57250 for concealed use in manufactured buildings.

 

[LarryFine]

Yes. I have used them, for example, when relocating bottom-fed kitchen counter receptacles to the upper cabinet bottoms.

I have also used the tap version to add a receptacle to an existing circuit to avoid the two-junction-box method.

 

[romex jockey]

My question is whether this community of experienced electricians and inspectors believes it is Code-compliant to use these NM cable interconnects for new modular home construction where they will be concealed in the wall?

No

and i was involved in a class action suit, part of which revolved around those exact 'connectors' , pre -'14 code

the company that manufactured them have been banned from doing biz in my state ever since

the company that peddled them here is long gone

~RJ~

 

[jrpgoose]

2017 and 2020 NEC 334.40(B) and 300.15(H). These are listed and are also approved by code to be concealed anywhere you can use non-metallic sheathed cable. I’ve used lots of them but I always tape the crap out of them for good measure. Overkill as they are listed. Also the guys name that owns this board Mike Holt says they meet code also. Just watch his latest Mike Holt Live videos where he’s asked this question specifically and gives explanation with code to back it up.

 

[don_resqcapt19]

2017 and 2020 NEC 334.40(B) and 300.15(H). These are listed and are also approved by code to be concealed anywhere you can use non-metallic sheathed cable. I’ve used lots of them but I always tape the crap out of them for good measure. Overkill as they are listed. Also the guys name that owns this board Mike Holt says they meet code also. Just watch his latest Mike Holt Live videos where he’s asked this question specifically and gives explanation with code to back it up.

334.40(B) does not let you install these in concealed locations for other than a repair of an existing circuit. They cannot be concealed where part of a new circuit.

 

[jrpgoose]

I just stated the code articles that apply. I didn’t plan on people not reading the code to get the specifics. It was only a reply to the above message saying you couldn’t use them at all and they were banned.

 

[jimport]

Splitting hairs, but what is the functional difference between usage for a repair and being used to add on to a circuit for a new receptacle? It has already be listed for the voltage and current expected to be imposed by conditions of use. This seems like safe on Monday, but not Tuesdays.

 

[Dennis Alwon]

NSI makes them and they have a strange statement that I don't quite get

This NM Splice and tap method provides a fast and reliable way to connect 12 and 14 AWG circuits using non-metallic (NM) cable. It eliminates the need for junction boxes, covers, fittings, connectors. It is approved for use in a variety of applications including: residential branch circuits, manufactured housing and pre-fabricated building structures. When adding new circuits in residential applications, NM connectors eliminate both the need to cut into the existing wire and the extra junction boxes and associated hardware required for the tap connection.

 

[jimport]

But is that marketing trying to increase sales without knowledge of code requirements or something else?

 

[paulengr]

But is that marketing trying to increase sales without knowledge of code requirements or something else?

Just saying you can have an “exposed” splice. So say I do a home run to an attic or basement (unfinished space) and I run short, or doing a remodel. Three choices. I can pull a whole new cable. I can install a box of some sort and splice in the box, or use these things. Sure we have all seen NM opened up and wire nutted out in the open but it’s a huge Code violation even with the weather proof wire nuts. To splice or branch legally you have to terminate the NM into another raceway or enclosure. So you could do it inside a conduit fitting or a box or a gutter but not inside a wall. And apparently these count so “inside” these connectors,

The idea behind concealed wiring is that you rarely have failures in the middle of a cable. It’s mostly either the loads or the connections. So normally NEC does not allow concealed connections. Plus it is almost impossible to test cable for faults if you have no idea how it is routed. Thus the prohibition against wiring where you can’t remove a cover for access. And this might sound like Mike Holmes but I’m not very comfortable with concealed joints whether legal or not. I’ve almost never had an issue with my joints but I have others and it’s just asking for trouble.

 

[jrpgoose]

Manufactured homes both Hud(Federal) and Boca (State) have been using them for decades. HUD homes are either hidden behind the siding in the wall or in the crawl space. Boca homes are almost only in the crawl spaces. I have been to lots of service calls on both types and if it’s a loose connection it seems it’s always the receptacles where the wire is squeezed in the back and there’s no box just flippers. Never have I seen one burned up or loose if installed correctly. They are listed and to the gentleman above about the new to old Mike Holt said the same exact thing. Why would it matter.

 

[LarryFine]

NSI makes them and they have a strange statement that I don't quite get

They mean that a typical tap into a straight run of NM requires cutting the cable, having to install two J-boxes, and add a length of cable between them, all due to a lack of the slack needed to re-join the cut ends. Once done, you can add a tap in either J-box.

 

[Little Bill]

They mean that a typical tap into a straight run of NM requires cutting the cable, having to install two J-boxes, and add a length of cable between them, all due to a lack of the slack needed to re-join the cut ends. Once done, you can add a tap in either J-box.

That's not how I read that. It sounds like they are saying no junction boxes needed, just use the product they offer. I don't think what they wrote is correct, but that is how it reads to me.

 

[LarryFine]

That's not how I read that. It sounds like they are saying no junction boxes needed, just use the product they offer. I don't think what they wrote is correct, but that is how it reads to me.

We're not disagreeing. Maybe I wasn't clear in my last post. I'm saying that they're saying that this device eliminates the need for what I described as the traditional method, and I agree with that claim.

Just to be clear, we're talking about the tap version, where a "socket" is installed on an uncut length of NM, and a separate "plug" (one of the two in the coupler version) is installed on the new NM.

The device does eliminate the need for two J-boxes in a taut run, and the need for one when there is enough slack to cut, strip both ends, and still have enough of both cable ends to enter one box.

So, yes, the devices are intended to be used without boxes. The housings are their own enclosures.

 

[Oldmaster2]

NEC states"for repair in existing building." Seems clear to me.