Wet/Damp Location for UTP

[RenBuckland]

In a ground floor interior conference room with metal conduit stubbed above the ceiling (non-plenum), in the slab to a floor box under the table there is an electrical and data outlet. The inspector stated that the data cable needs to be outdoor rated. He then issued a notice for re-inspection stating that "110.3(B) or 800.113 must show me that your cable is listed for wet and damp location. UTP type cable is listed for wet damp location."

110.3(B) and 800.113 just state that the cable must be listed and labeled for proper use.
NEC 100 Definitions I. General defines - Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather. - So he's got me on concrete slab in direct contact with the earth
but
800.47 states The requirements of 310.10(C) shall not apply to communications wires and cables.

I would just replace the CMR rated cable pulled with CMX rated but I feel like that would be a violation as well as the total run is about 125' from IDF to floor box and the conduit is only under the floor and up the wall (30').

Should I just run the CMX rated cable in the conduit and then switch it to the CMR above the ceiling for the 95' run back to the IDF since CMX can't be run in vertical runs or riser communication raceways or riser cable routing assemblies as per 800.154(a) or plead my case with a different argument?

 

[hbiss]

UTP is not a cable listing, it stands for Unshielded Twisted Pair which just describes the type of cable or cable construction. All data cable, regardless of it's listing is either UTP or STP (Shielded Twisted Pair). So right there he doesn't know what he's talking about.

CMR is a listing, Communications Multipurpose Riser which means that it can be used for communications and other uses vertically from floor to floor. CMR is the most used where a plenum cable is not needed. This and CMP is what you want to stock.

Contrary to what you may think, CMX is NOT Communications Multipurpose External. What it is is the lowest in the communication cable hierarchy with uses restricted to residential or other small installations where the number of cables is few to limit flame spread. Not something most of us would want to stock.

So, getting back to your question. Is the conduit to the floor box in a slab-on-grade? Is so it is a wet location. If it is a slab above grade it is not a wet location. That said, Art. 800 has no requirement for a communications cable to be listed for a wet (or dry) location. It is strictly a design issue, but it would behoove you to use a cable designed for direct burial in such instances if you want it to last.

310.10(C) couldn't apply to communications cables even if it was supposed to.

Then there is 110.3(B)

Installation and Use. Listed or labeled equipment shall be
installed and used in accordance with any instructions included
in the listing or labeling.

I don't think I have ever seen the manufacturer's instructions for a CAT6 cable that isn't made for direct burial say "dry locations only". There are cables designed for direct burial/wet/outdoor locations:

https://cdn.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/7408-source/options/download

-Hal

 

[Fred B]

Just a side thought, would anything suggested become applicable if the cable in question was POE and not just communications?

 

[hbiss]

Just a side thought, would anything suggested become applicable if the cable in question was POE and not just communications?

No. POE is CL2 making the cable now subject to 725 CL2 requirements. I don't know of anything there that would change anything said.

Edit: I should point out that our thinking has changed about data cabling falling under Art 800. It apparently is under Art 725 so the inspectors reference to 800.113 is inaccurate. But I can't blame him, I've insisted it was under 800 for a long time. And no, nothing changes as far as what I said above.

-Hal