Network Cable support above dropped ceiling?

[jlklein]

Hi folks,
Long time lurker, recently re-registered (was under an old email). I've read a lot about the above on the site, and other references, plus have been discussing with my electrician son (works out of state, so might be different local codes).

Our church is finishing up renovating a 2 story building section (construction professionals mission group did the heavy lifting), and I'm doing the network and AV cabling, as I'm the AVL Tech Director there, and also it's my day job at work (Gov't Agency AV Tech Lead, started as an AV tech). Lots of network now in AV, so got into the network side many years ago as well.

Anywho, I ran plenum CAT6A STP to all of the room jacks on each floor, as well as a few WAP and IP camera locations per floor. All wall jacks are piped up above each floor's ceiling (1st floor to above drop ceiling; 2nd floor to attic) and each floor's cable bundle is run to the adjacent space to the network rack via a common 2" pipe per floor. No issue with the 2nd floor, but the inspector told our Building/Grounds POC (who is a Gov't PM for various building, comms, grounds projects at work) that my network cables above the 1st floor drop ceiling needs to be tied up, which is news to me.

So, I've found two NEC sections regarding this type of install, in large part to this site and Mike's PDFs:

• NEC 820.6 says, "Low-voltage and limited-energy cables must be supported by the building structure in such a manner that the cables will not be damaged by normal building use.These cables cannot be strapped, taped, or attached to electrical raceways."
  • Quick question: are electrical raceways "conduits" or does it include cable trays? The pics I saw seem to indicate conduit, so, not that we have cable trays, but I'm curious. (It's a blessing, and a curse...).
• 800.5 Access to Electrical Equipment Behind Panels Designed to Allow Access.
  Access to electrical equipment shall not be denied by an accumulation of wires and cables that prevents removal of panels, including suspended ceiling panels .

I also found an applicable reference in Mike's Communications Systems PDF guide as follows, which seems to reference 820.6, but adds a "secured" requirement in addition to the "supported" requirement of 820.6:

• [800.24] "Exposed cables must be supported by the structural components of the building so the cable will not be damaged by normal building use. The cables must be secured by straps, staples, cable ties, hangers, or similar fittings designed and installed in a manner that will not damage the cable."

Here's my dilemma:

• All of my network cable above the first floor drop ceiling is running perpendicular through the triangle openings in the existing steel ceiling rafters, so is supported by the building structure, and there is no danger of cable damage due to movement, sharp edges, or weighty cable bundles (it's only 11 cables for the whole 1st floor).
• The main cable bundle for the 1st floor is run through the steel rafters above the main HVAC duct, so is nowhere near the dropped ceiling grid.
  • The only exceptions are:
    • Where single cables veers off to wall conduit running down to one of the two network jack wall plates per room or to one of two WAP locations.
    • Where the 2" pipe coming down from the network closet into the 1st floor, the 1st floor cable bundle runs parallel between two steel ceiling rafters, but on top of an HVAC duct also running between the two rafters and above the dropped ceiling to a 2" pipe running over the hallway to the other rooms (except the 2 cables terminating in the room). None of this cable is anywhere near the dropped ceiling tiles.
• In no case is any of the cable laying over or on any ceiling tile, even when going to one of the two WAP's (which are clipped to the underside of the ceiling grid with the manufacturer's included mounting hardware, which was not called out of an issue). Cable going to the WAPs is even velcro'd up to keep it off the ceiling tile where the WAP is.

So, the only thing I can think if is the AHJ (my new term I learned from my son) has a personal definition of "hangers, or similar fittings designed and installed in a manner that will not damage the cable" that doesn't include the steel ceiling rafters supporting the cable literally every foot. Are "hangers" defined anywhere in the NEC where it would specifically not apply to running the cables through the steel ceiling rafters? I've seen "cable hangers" that are simply big J-hooks and are less secure than running them through the steel ceiling rafters.

Granted, there isn't a lot of cable to tie up and satisfy the Inspector, but I always have a need to know the "why" and what the "policy" is, vs someone's preference. This is not helped by the fact that I am often faced with this at work while doing AV fitups in new buildings or space rehabs, and the Gov't Infrastructure and Logistics personnel who handle the buildouts try to pass off their personal preferences as "Gov't requirements". Nearly every time I've asked them to provide documentation to support the "requirement" it doesn't exist, or has "suggestions" that are not "requirements. So, I tend to ask why...a LOT

I do appreciate any insight, even if just to help me learn if nothing else

Thanks,
Jeff

 

[tom baker]

That’s a long post can you shorten?

 

[hbiss]

That’s a long post can you shorten?

Ahh, yeah. But I can give you a short answer.

1) Your cables can't be supported or lay on the ceiling or grid. They can't be attached to the hanger wires.
2) Cables can't be attached or supported by other conduits, plumbing or other wiring. Laying on top of HVAC ducts is a gray area. Depends on how much and how often. Sometimes it can't be avoided.

Running cables through the trusses is fine. If your cable is subject to damage that's not something that the NEC cares about. No special hangers are required.

Simple as that.

-Hal

 

[Little Bill]

I did a job in a city about 100 miles from me and was unfamiliar with their inspectors. I had to run several runs of Cat5E and was unsure if the whole area was plenum area or not so I chose to use all plenum rated cable. That was what I was sure the inspector would look at first. But no, he wanted to see that it was supported. In an area he couldn't see, actually, too lazy to climb up and look, he asked what I used for support. I told him bridle rings that were already there. He was trying to tell me that I had to have been the one to install them as I couldn't use something that was used already. I had to explain to him that the rings were there but nothing was in them. I don't know why they were unused but they were. Even if they were used, I don't see what that would matter since my cable were supported and not being supported by other cables, conduits, or wiring.
Long story short, inspector was more concerned over support than the type.

 

[hbiss]

He was trying to tell me that I had to have been the one to install them as I couldn't use something that was used already.

I don't recall seeing anything in the code that says you have to sign and date your supports.

I think the rule is that wiring can't be supported off a dissimilar system. If I'm running new MC I see no problem with putting it in with existing MC or even Ty-Raping it to some existing. Same goes for low voltage.

But above all, the cardinal rule is to keep your cables off the ceiling grid and tiles.

-Hal

 

[Little Bill]

I don't recall seeing anything in the code that says you have to sign and date your supports.

I think the rule is that wiring can't be supported off a dissimilar system. If I'm running new MC I see no problem with putting it in with existing MC or even Ty-Raping it to some existing. Same goes for low voltage.

But above all, the cardinal rule is to keep your cables off the ceiling grid and tiles.

-Hal

That was my point, the cables were supported so why was he worried about where the bridal rings came from?

 

[hbiss]

His own rule apparently.

-Hal

 

[cabledawg]

You can use "J hooks to accomplish that. Which is Industry standard to keep them off the Grib as long as you Shoot your own Grid wire or look for abandoned grid wire that doesnt attach to the Grid, It can be clipped to the Grid but not the Main Support of the grid. Hope this helps.