Box Barriers

[infinity]

Does anyone know how the geniuses actually approved this (code change 2017)? Really, a metal barrier that is probably less than 1/16" of an inch thick. A barrier needs to be added to a box calculation but these two receptacle devices both count as only a 2 conductor deduction.

314.16
(A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections
and, where used, the space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with their
volume or are made from boxes the dimensions of which are listed in Table 314.16(A). Where a box is provided with one or
more securely installed barriers, the volume shall be apportioned to each of the resulting spaces. Each barrier, if not
marked with its volume, shall be considered to take up 8.2 cm 3 ( 1 ∕ 2 in 3 ) if metal, and 16.4 cm 3 (1.0 in 3 ) if nonmetallic

 

[synchro]

1/16" x 2" x 4" = 0.5 in³ and so that's a reasonable number for a barrier.
But as you show, the variation in receptacle sizes is all over the place. The volume taken up by barrier is "in the noise" by comparison.

 

[don_resqcapt19]

The PI only asked for the rule to provide for calculating each compartment, that is created by the dividers, separately. CMP-9, on its own added the part about the volume of the dividers.

 

[steve66]

Really, a metal barrier that is probably less than 1/16" of an inch thick.

So calculate the volume the divider actually takes, and write it on the side?? I don't see where it says factory labeled or marked....

 

[electrofelon]

They have to think of enough changes every three years.........

 

[electrofelon]

Funny, right now I am putting receps in a 2 1/2 in deep gem box with 2 12-2 MC and 1 MC clamp. I'm pretty sure everything will be fine.