NEC 820 & CATV cable above drop ceilings

[MarkMcLain]

On our campus (www.apsu.edu), we're having to install security camera's at every building entrance & all hallway junctions - (why? so there can be after the fact I-told-you-so meetings). The question is, can the installation contractor be shown relevant code articles as to why cabling cannot(shallnot?) be just thrown across drop ceilings? I've read thru 820 and don't see hard ground to stand on to 'encourage' them to use existing comm cable trays and existing raceways set up for cat5 & telecom cable runs. The contract itself doesn't specify this, but does the NEC (..."shall follow all NEC & local electrical codes"...)?
Thanks for any feedback.

 

[bphgravity]

Re: NEC 820 & CATV cable above drop ceilings

Maybe Section 820.6 or possibly 820.5?

 

[MarkMcLain]

Re: NEC 820 & CATV cable above drop ceilings

So, does one state that the CCTV cabling has been run is in the way of easy access to electrical junction boxes, as per NEC 820.6 ??? Please use cable trays and other supports meant for this purpose - or, to quote in context:
" 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."
(the phrase 'must be' doesn't sound as strong as "shall be")

?

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

Naa, cable must be supported independently of the ceiling grid and supports but where the heck is it?

-Hal

 

[MarkMcLain]

Re: NEC 820 & CATV cable above drop ceilings

OK, 300-11(a)(1)&(2)

Dang it! 'Somebody' has 'borrowed' the office copy of the 2002 code here and I'm looking at the '96 code book. Does the above still apply?

 

[bphgravity]

Re: NEC 820 & CATV cable above drop ceilings

Chapter 8 is not subject to the requirements of of Chapters 1 - 7 except where the requirements are specifically referenced in that chapter.

I don't see 330.11(A)(1)or(2) anywhere in Article 820. The only reference I see is 300.4(D) which doesn't apply to your question.

 

[MarkMcLain]

Re: NEC 820 & CATV cable above drop ceilings

The phrase below seems to be all that is stated concerning CATV cables above a drop ceiling:

" 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."

'Normal building use' seems to be a subjective call as well.

Perhaps there is no enforcement wording to achieve my goal.

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

I don't see any reference to 300.11(A) or (A)(1) anywhere in chapter 8.

I guess we have been wasting a lot of money on hangers and labor huh?

-Hal

 

[MarkMcLain]

Re: NEC 820 & CATV cable above drop ceilings

In Mike Holt's free pdf download of 'LowVoltBook.pdf' fig. 7-19 page 33 it shows cable loosely hanging in drop-ceiling-T framework and denotes it as a 'VIOLATION' in ref to 820.6 !!?!
"(Support 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, Fig 7-19. These cables cannot be strapped, taped, or attached to electrical raceways, Fig. 7-20. System Sections ? CATV, MATV, CCTV 820-6, 820-10(c) and 820-52(e) ? Control and Signaling (Class 2 and 3) 725-7 and 725-54(d)* ? Fire Alarm 760-8 and 760-54(d) ? Optical Fiber 770-8 ? Network-Powered Broadband 830-7 and 830-58(d) ? Radio and Television 810-12 ? Telecommunications 800-6 and 800-52(e) FIGURE 7-20 )" I think I could carry the printout of fig 7-19 and say "SEE THIS AND OBEY THE CODE".
(Somehow, this feels a little weak). Thanks for the feedback.

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

Well, to be honest I never looked in Article 800 for this until now and I have been doing LV work for better than 10 years. I am familiar with 300.11(A) and (A)(1) and have no reason to believe that it shouldn't (or didn't) apply to LV cables as well by some reference to it in 800.

Matter of fact everything I have ever read relating to LV installations in ceilings relates 300.11 ceiling requirements. I even remember some years ago a discussion about relaxing this requirement to allow some minimal amount of LV cables to be run across a ceiling. What was that all about?

I don't know of any LV cabling company nor have I ever seen any work by such a company or contractor that didn't follow 300.11 ceiling requirements. I don't know of an AHJ that would allow cabling on the ceiling grid, but since this now appears not to be against the NEC it would be open to argument by somebody who wants to cut corners.

I really think the NEC dropped the ball here and made a mistake by not including a reference in 800. I can't see what difference the kind of wiring makes, the intent is obvious.

-Hal

[ July 26, 2004, 01:26 PM: Message edited by: hbiss ]

 

[MarkMcLain]

Re: NEC 820 & CATV cable above drop ceilings

Is somebody saying that the illustration 7-19 (ref prev post) is not correct?
Everything we do in-house is done with a thought that we'll be seeing it again and dealing with it over the years. Lord knows it's hard enough to work above a drop ceiling on a ladder between tables & desk's. All new work we do IS properly suspended by the building and NOT laying on the drop ceiling BECAUSE we've got to work up there again and again. In the older buildings, there ARE locations that are hard(impossible) to get up into because EVERYTHING was just laid up there with no consideration of future work. Someday, those buildings will be demo'd and new one's will be built.

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

Is somebody saying that the illustration 7-19 (ref prev post) is not correct?

I would. According to the NEC as long as it's supported by something other than a raceway up there it's OK. Does removing all ceiling tile constitute "normal building use"? Heck, just lay your bundles right down the middle of the ceiling as long as you can remove tiles either side of it to get at the electrical stuff.

-Hal

 

[tom baker]

Re: NEC 820 & CATV cable above drop ceilings

"Matter of fact everything I have ever read relating to LV installations in ceilings relates 300.11 ceiling requirements. I even remember some years ago a discussion about relaxing this requirement to allow some minimal amount of LV cables to be run across a ceiling. What was that all about?"
This proposal was rejected at the 2002 NEC annual meetng. A tile here, a tile there, where would it stop?

 

[hurk27]

Re: NEC 820 & CATV cable above drop ceilings

Look at 800.5

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 .

It does not allow even the blockage of one tile.

, 800.6,

and 800.53 which might apply if these spaces are for enviromental air?

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

This proposal was rejected at the 2002 NEC annual meetng. A tile here, a tile there, where would it stop?... Look at 800.5... It does not allow even the blockage of one tile.

OK, then I can hang my 12" bundle of cables on the hanger wires right!

Sometimes I just don't get where where these guys are coming from that write the NEC. I can't think of any reason LV wiring should be treated any differently in a suspended ceiling than chapter 3 wiring and I don't think they do either.

Get rid of 800.5, renumber 800.6 to 800.5 and add "The installation shall also conform with 300.4(D) and 300.11.

Problem solved. Geeze!

-Hal

 

[don_resqcapt19]

Re: NEC 820 & CATV cable above drop ceilings

Wayne,
800.5 is very subjective. In my opinion the wording only prohibits laying the cables on the tiles if there is so much cable that it physically prevents the removal of the tile. It would take a large amount of cable to actually prevent the tile from being removed.

Hal,
I agree that the code needs some improvement here. A good place for 2008 proposals.

Don

 

[hurk27]

Re: NEC 820 & CATV cable above drop ceilings

I agree with that. But I have many times had to try to get into a drop ceiling and couldn't because of all the cables. Or open a tile and have pile of spaghetti fall down. While most of us that have to deal with this after the cable installer is long gone knows not to allow that many cables as to block the tile. But there are many that don't follow this and just keep piling the cables up and when we have to go back and do a repairers or add more circuits and have to have access to these places will be thankful when we don't have this problem. The problem is how do you limit the amount of cables? How much is to much? and what about having a 100' of extra cable just laying on the tile? Any way the CMP could word a requirement like this would be hard. as it would be left up to the AHJ to determine what is considered as blocking the tile when it could be argued that it's cable and could be just moved.

 

[hbiss]

Re: NEC 820 & CATV cable above drop ceilings

The best way would be to have no difference between chapter 3 wiring and chapter 8 wiring in this respect. I don't understand why there is a relaxed requirement for LV cables when ANY wiring or cable is equal from the standpoint of obstructing and loading the ceiling or falling down on fireman's heads.

Sounds to me like the NEC caved to the LV interests here because many in the telecom/IT business want to work as cheaply as possible and don't care how the cable is run as long as their connected equipment works.

-Hal

 

[hurk27]

Re: NEC 820 & CATV cable above drop ceilings

Hal

Sounds to me like the NEC caved to the LV interests here because many in the telecom/IT business want to work as cheaply as possible and don't care how the cable is run as long as their connected equipment works.

Where do you see that the NEC caved in?
800.6 requires that LV cables have to be supported only by the building and 800.5 requires that they can not be allowed to block access panels including drop ceiling tiles.
It's the LV guys that don't follow this. as it is in the NEC.

 

[don_resqcapt19]

Re: NEC 820 & CATV cable above drop ceilings

hurk,

800.6 ... Cables installed exposed on the outer surface of ceiling and sidewalls shall be supported by the structural components ...

It appears that this rule only applies to cables that are normally exposed to view, not to those that are above a lay-in ceiling. Yes, I know that per the code, above a lay-in ceiling is "exposed", but 800.6 goes a step beyond and says "exposed on the outer surface". In my opinion this rule does not apply to cables above the ceiling.
Don