Device Box - Steel Stud & BX

[Dave123]

I'm new to the trade so its quite possible the question I'm about to pose is a bit silly.

The IBERVILLE device box for steel stud construction (BC3104-LSSX) does not have a positive stop where the BX enters the box and gets clamped down. At first glance this box appears to be for NMSC only. However, the carton stats that it's approved for both Loomex and BX.

I find that the anti-short can be easily squeezed out of the BX without having something that the anti-short is be pressed up againsted.

Hope this makes sense.

Dave

[Joe Camel]

I?ve seen those positive stop clamps be the source of problems as the wire insulation can be cut by the sharp edges as the device is pushed into the box. I always make it a habit to tape the anti short in place with electrical tape, whether this is code or not someone can respond, but I know the anti short will not be squeezed out even in a NM clamp.
Joe

[Dave123]

Upon review of my initial message I can see that I never really asked a question, I just stated the problem I was experiencing.

So here's the question. Is there a code rule that covers how BX cable should be terminated and fastened to a device box aside from the fact that an anti-short must be used and be visable.

Thanks,
Dave

[bigrockk]

Hello Dave

Rules 12-602 to 12-618 apply to armoured cable work.

Have you tried not pushing the bx past the cable clamp.
In other words, don't let the armour pass past the cable clamp,but do let the little tab on the anti-short stick out below the clamp.

Hope this helps.

[Dave123]

This is going to be difficult to explain without a picture, but here goes...

Any job that I?ve worked on to date while working with BX has been mostly with device boxes that have knockouts. In this case connectors for BX have been used (e.g., L-16 I believe that?s what there called). In a few cases I?ve also used boxes without knockouts but these were also designed for BX. One type of box has the clamp designed with a pocket (kinda) that?s somewhat contoured to the shape of the BX and large enough to clamp a sufficient amount of BX. In another box, again without knockouts, there?s the portion of the clamp that presses up against the armour as well as a piece that?s at 90 degrees (perpendicular to the armour) thus providing some restriction to the armour being pushed to far into the box (similar to the restriction on the L-16 connector). It is this 90 degree piece that I?m referring to. It does not exist with the shipment of boxes (without knockout) we received, yet the carton states that it?s approved for BX and Loomex.

Bigrockk, thanks for the suggestion. This is what I?ve been doing so far but not always successful. I?ve also checked the work of others (we?re doing about 500+ units) and their work is also very inconsistent with these boxes. Additionally the width of the piece that clamps against the BX is very narrow and also has a centre grove protruding out, again as though it were for Romex only. This grove also makes it difficult to get a snug fitting under the clamp ? it either slips between the BX and anti-short, sometimes pressing the anti-short out or the BX slides to far out all together.

Oh, one other note. We did have some other Loomex / BX boxes that had the clamping setup I referred to above (piece that clamps against BX and also restricts the bx and anti short from entering box), so I started removing the unused clamps using them in place of the others ? they?ve all been used up now.

Anyhow enough said on this? don?t like it but I guess I?ll just have to keep working with this stuff until it?s used up.

Dave

[Powerplay]

I like to tape the anti-short in place in those type of boxes also, but to ensure a good bond on the exterior sheath of the bx, I tape the little protruding tab to the conductors, to prevent it from slipping out. Another practice I have been doing recently is to try and enter the device boxes from the same side to be able to remove the extra clamp, which reduces the chance of nicking wires when wires attached to the device are pushed back in the box, especially with #12 wire. It also allows more room for possible future replacement of light switches with dimmers.

[chrisd]

These new boxes are in my opinion, another attempt by our suppliers to have one less product on the shelf to minimize inventory and thus increase profit. The manufacturers have lobbied to have them approved for BX and bumbling bureauocratic mess of the approval system let this one through.

For reasons already discussed here they are a complete garbage product. The clips dont hold the cable, and the bushings fall out.
They increase labour cost for the installer having to tape the bushings, and they are dangerous if this is not done. They are are approved whether they are taped or not.

This time there doesnt seem to be an alternative.
Maybe it's time to complain. Who do we complain to about these matters?