ECN Forum Forums Code Related Discussion NEC & other Code issues Using receptacle boxes for supporting cable drops.

Thanks to all for the replies to my last posting.

My boss wants me to use the junction boxes where I am mounting the receptacles that power individual machines, to also support the cable drops to the same machine. His thought is to drill a hole thru the side of the box and mount a hook to hold the kellum grip. I'm pretty sure that this isn't right but I need to find it in the code.

We are using 12/4 and 10/4 SO cords on all of the machines, with a woven strain relief to support the cable at the ceiling and twist-locks for the disconnect plug. If I am not allowed to use conduit to support things, how can I be allowed to drill thru the side of a junction box to hang a cable?

I'm looking thru the 2002 code book but I haven't found it yet. Can anybody help me with this?

Thanks

Larry C

Ah, another possible 'gray' area emerges.
THe box is secured to the structure?? Why can't the kellum be secured adjacent to the box on whatever is supporting the box??

Not to throw a monkey wrench, but is the install you are doing compliant with 400.7 & 400.8? 'Cord drops' are becoming dinosaurs around here.

John

It may be a judgment call. For example, a cable connector with integral mesh grip secured by a locknut shouldn’t be a misapplication. [Stay away from concentric KOs, though.] http://63.90.33.38/wiring/section-t-datasheet.asp?PN=CG814SST

On the lower end, a female locking connector on the cord and a “motor flange” integral to the floor-level equipment is fairly common.

I should do a better job of describing the setup.

Typical machine: Bridgeport Horizontal Mill
Ten feet of 10/4 SO cable exiting control box. Eight feet from the machine end of cable, a 2 loop woven mesh cable grip. At the end of the cable, a twist-lock plug. Mounted on the ceiling truss, a 4 11/16" square box with cover and mating receptacle.

My boss wants me to drill a hole and mount a hook INTO the side of the receptacle box to hang the cable grip loops. I would rather use a separate beam clamp to mount the hook.

As BJ said, a judgement call.

Boxes are designed for raceway/cable/etc entries and containing conductors. Modifying the box, by drilling a hole, could be considered a 'violation of the listing' or 'not complying with mfg directions/instructions'. No intention of starting a "definition and wordsmith debate is intended!

It is probably cheaper (labor) to install a beam clamp, then to invest time in drilling the box.

Your AHJ may require the beam clamp/hook, and closing the hole you drilled, so you may end up replacing the box if you can't satisfactorly close-up the hole.

John