# CAT  6  Wiring



## globe trekker (Aug 23, 2012)

According to Article 334.12(A)(2) in the 2008 NEC, Type NM wiring

is not allowed in dropped or suspended ceilings.

*QUESTION:* Are CAT 6 wiring assemblies allowed in the dropped

or L.A.T. ceilings? Please cite your references, ..for or against.

In my application, the space above the L.A.T. ceiling grid is not

being used as an environmental air plenum of any type.  The

CAT 6 cables are CMR rated!

Thank you!

.


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## chris kennedy (Aug 23, 2012)

globe trekker said:
			
		

> Are CAT 6 wiring assemblies allowed in the dropped
> 
> or L.A.T. ceilings? Please cite your references, ..for or against.


All day long. Code reference? As the NEC is a permissive document there is nothing that says you can't so you can.


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## chris kennedy (Aug 23, 2012)

See page 3 item E in this link to view Erico Caddy J hooks designed for support of cat5/6 cables from drop ceiling support wires.


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## Gregg Harris (Aug 23, 2012)

globe trekker said:
			
		

> According to Article 334.12(A)(2) in the 2008 NEC, Type NM wiringis not allowed in dropped or suspended ceilings.
> 
> *QUESTION:* Are CAT 6 wiring assemblies allowed in the dropped
> 
> ...


 334 does not apply to your CT6 wire . Reference Article 800 Communication Circuits.

And yes it can be run in the ceiling 800.21


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## globe trekker (Aug 24, 2012)

Thanks Chris & Gregg for your input!

I should have clarified my original question more..

What I have is some CAT 6 wiring assemblies that are being

installed above a L.A.T. ceiling grid. Currently, all of the

assemblies are just laying on the acoustical insulation which

is laying top of the tiles themselves.

I referenced Article 334 for NM wiring assemblies, because

(to me) the application is similar in that, there are no

raceways for the wiring assemblies. Article 334.12(A)(2)

prohibits non-metallic sheathed cable assemblies to be

installed above these ceiling grid applications.   Sorry for

the dissimilar reference! The CAT 6 assemblies are metal

sheathed.

While I agree that these type wiring assemblies are allowed

to be installed above the ceiling grids themselves; without

raceways, they are not allowed to be just left on top of the

ceiling grid without being supported in an approved manner,

which is what I currently have.

I received a PM directing me to Article 300.11(A) in the 2008

NEC. This article reference provides me with the information

similar to what Chris K. posted, _"..Cables and raceways shall_

_not be supported by ceiling grids."_

Again, "much thanks" for the input!

.


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## Gregg Harris (Aug 24, 2012)

globe trekker said:
			
		

> Thanks Chris & Gregg for your input!I should have clarified my original question more..
> 
> What I have is some CAT 6 wiring assemblies that are being
> 
> ...


That is the correct reference for the support, also look at 800.21 and 800.24 mechanical execution of work and 800.25 for Abandoned cables shall be removed-------etc


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## moose (Aug 27, 2012)

Trekker,

It also depends on what state you are in. Here in Massachusetts, there is an amendment to 334.12(A)(2) that also alows NM above a dropped ceiling if it follows the framing or is on running boards. It also allows drop downs to luminares


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## globe trekker (Aug 29, 2012)

To further the discussion on this topic, ..the installers of the CAT 6

wiring assemblies have removed all of the cable assemblies off of

the top of the ceiling tiles and attached them (in some locations)

to some EMT conduit and to the ceiling tile grid support wires.

In reading the 2008 NEC, Article 300.11(B)(3) seems to allow this

type of attachment to a raceway, while Article 800.133(B) seems

to prohibit any attachment to a raceway.

Can someone please clarify this for me? Thanks! 

.


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## Dennis (Aug 29, 2012)

Also if the ceiling is a plenum then it must be plenum rated cat wire


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## globe trekker (Aug 29, 2012)

Dennis,

In my application, above the ceiling is not a plenum, but the cable

assemblies are rated CMR!

.


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## Dennis (Aug 29, 2012)

globe trekker said:
			
		

> Dennis,In my application, above the ceiling is not a plenum, but the cable
> 
> assemblies are rated CMR!


If it is not a plenum than any cat  wire can be used.


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## Gregg Harris (Aug 29, 2012)

globe trekker said:
			
		

> To further the discussion on this topic, ..the installers of the CAT 6wiring assemblies have removed all of the cable assemblies off of
> 
> the top of the ceiling tiles and attached them (in some locations)
> 
> ...


800.133 (B)  prohibits it from being attached to conduit. The purpose of the prohibition is the lack of heat dissipation for the conductors in the raceway when the wires are bundled and attached.


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## globe trekker (Aug 30, 2012)

Are there any heat dissipation issues if / when the CAT 6 cable assemblies

are bundled (zip tied) together and then zip tied to a bldg. structural

member?

.


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## Gregg Harris (Aug 30, 2012)

globe trekker said:
			
		

> Are there any heat dissipation issues if / when the CAT 6 cable assembliesare bundled (zip tied) together and then zip tied to a bldg. structural
> 
> member?


No there is very little current carried by communication wires as apposed to standard electrical service. This is where NEC 300.11(B) Raceways Used as Means of Support (2), comes into play Class 2 circuits used to control equipment.

If there where a heating and AC system that was wired using EMT the 24 volt control wire could be attached to the conduit as a support.

.


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