Raceway integrity and approved bonding techniques

[DaronWilson]

I've spent some time in the NEC trying to find some answers on this but don't really seem to be able to pin it down. The situation is a cable tray for data cables, and at several places where a fire wall or narrow space is present, 4" EMT conduit raceways are used (sleeves) to get through the wall then a return to cable tray. The conduit sleeves vary in length, some short (12") some up to 15 or 20 feet before they return to cable tray. The electrician is using #6 THHN bonded to the cable tray with a split bolt connector, through one of the sleeves. Once on the other side he has drilled a 1/4" hole in the 4" EMT and put a bolt and nut holding an aluminum lug on the outside of the EMT. The wire is routed through several of the lugs, one on each sleeve, and then bonded to the cable tray.

It seems to me that drilling a hole in EMT conduit would violate a listing of some sort, as would having anything inside the EMT that would reduce the overall volume for wire and/or potentially damage the wire. I understand the logic of it being bonded now, and much easier than fittings or clamps, but it doesn't seem correct and I'm unable to find details in the NEC on drilling holes in raceway, this may be a perfectly acceptable method of bonding but I had not seen it before.

 

[infinity]

We never bond sleeves for data cables. And since these are just sleeves I don't see how the Articles that pertain to complete raceway systems would apply.

 

[wwhitney]

It seems to me that drilling a hole in EMT conduit would violate a listing of some sort

Maybe, but you don't need a listed product for a sleeve, so that's moot. You could use a piece of cast iron DWV for your sleeve (if the interior were smooth enough not to damage your cables, and if the firestopping detail permitted that sleeve material).

Cheers, Wayne