Clamp fill, 314.16(B)(2) NEC 2014

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jumper

jumper

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A new section was added to 314.16(B)(2) in the 2014. I just saw it yesterday.

I bolded the new wording.

What the heck does it mean? Any example of the box and clamp that it refers to?

(2) Clamp Fill. Where one or more internal cable clamps,
whether factory or field supplied, are present in the box, a
single volume allowance in accordance with Table 314.16(B)
shall be made based on the largest conductor present in the
box. No allowance shall be required for a cable connector with
its clamping mechanism outside the box.

A clamp assembly that incorporates a cable termination
for the cable conductors shall be listed and marked for use
with specific nonmetallic boxes. Conductors that originate
within the clamp assembly shall be included in conductor fill
calculations covered in 314.16(B)(1) as though they entered
from outside the box. The clamp assembly shall not require a
fill allowance, but the volume of the portion of the assembly
that remains within the box after installation shall be excluded
from the box volume as marked in 314.16(A)(2).
 
From ROP 9-37 Log #3414 NEC-P09, in part

Submitter: Steve Carle, Advanced Currents Corp.

Substantiation: The connector fitting introduced in the companion proposals
is not addressed in the current box volume and conductor fill calculations. This
proposal would give clarity as to how to calculate volume and fill when using
connector fittings to maintain product safety.
Note: This is a companion proposal to 100, 300.15 and 334.30
Note: Supporting material is available for review at NFPA Headquarters.

Panel Meeting Action: Accept in Principle
Add a second paragraph to 314.16(B)(2) as follows:
A clamp assembly that incorporates a cable termination for the cable
conductors shall be listed and marked for use with specific nonmetallic boxes.
Conductors that originate within the clamp assembly shall be included in
conductor fill calculations covered in 314.16(B)(1) as though they entered from
outside the box. The clamp assembly shall not require a fill allowance but the
volume of the portion of the assembly that remains within the box after
installation shall be excluded from the box volume as marked in 314.16(A)(2).

Panel Statement: CMP 9 does not agree that the clamp\termination devices
presented during the consideration of this proposal extend the margins of the
box to encompass the extent of the devices. Therefore, the devices cannot be
considered as being entirely located within the box, and CMP 9 has relocated
the coverage and renamed the devices accordingly. The conductors that
originate within the termination device do so in a similar configuration and in
the same sizes as comparable conductors entering from a cable assembly or
raceway and for this reason CMP 9 has disallowed the usual permission to
leave uncounted those conductors that do not leave a box. CMP 9 conditions
this action on favorable action on Proposal 7-47 by CMP 7. CMP 9 believes
that the principal responsibility for determining the technical merit of this new
approach should rest with CMP 7.

Apparently some new connector/fitting.
 
How does this product comply with the rules for free wire length and accessibility of the terminations?

I see the prefabed boxes with devices being destroyed by the drywallers.
I don't think that I have seen many plastic boxes mounted to studs that are perfectly flush so the prefabed boxes with the devices without ears being at the right position for plates after the finish of the wall.

It just looks like a bad expensive idea.
 
CallMeJC said:
Nope.
Any idea how you would get to the wire terminations after sheetrock is installed?
Click to expand...

Unless you could remove the box, otherwise, I think not possible. I don't see a place to buy the boxes, just a site about them. I don't see how they could be used per NEC.

Our outlet boxes don’t require entry holes because cables connect on the outside of the box.
 
Watched the video, I still dont see how it works. Best guess is the NM goes into a wago-type receptacle, then there would be pre-wired switches and what not with factory pigtails going to a plug that just plugs into the box.
 
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