Low voltage wiring in raised floor

[Brian@verisign]

I'm in the Northern Virginia area and was wondering if anyone had any knowledge of whether or not network cabling in the raised floor of a data center needs to be Plenum Rated? My raised floor is a plenum and has dedicated HVAC supplying air to the sub-floor to cool the IT equipment. I came accross NFPA Article 645 which states it's not required to be Plenum Rated but I'm not sure if my county follows this. Thanks for any help you can provide.

 

[acrwc10]

I'm in the Northern Virginia area and was wondering if anyone had any knowledge of whether or not network cabling in the raised floor of a data center needs to be Plenum Rated? My raised floor is a plenum and has dedicated HVAC supplying air to the sub-floor to cool the IT equipment. I came accross NFPA Article 645 which states it's not required to be Plenum Rated but I'm not sure if my county follows this. Thanks for any help you can provide.

I think you answered your own question. Plenum = Plenum rated cable.

 

[paul]

I'm in the Northern Virginia area and was wondering if anyone had any knowledge of whether or not network cabling in the raised floor of a data center needs to be Plenum Rated? My raised floor is a plenum and has dedicated HVAC supplying air to the sub-floor to cool the IT equipment. I came accross NFPA Article 645 which states it's not required to be Plenum Rated but I'm not sure if my county follows this. Thanks for any help you can provide.

There are strict requirements in 645 that all must be adhered to in order for you not to use the plenum rated cable. Firewalls, EPO buttons, no air supply/return from outside the room, etc.

 

[ron]

Follow Paul's advice.
First determine if you are compliant with the prerequisites of 645 (found in 645.4), then if so, the NEC would permit using non-plenum rated cable below the floor. Be careful, although the NEC would permit t, the Fire Marshall may then invoke NFPA 13 and require sprinklers or some other type of fire suppression below the floor, since there would then be "combustibles". Of course plenum rated cable is combustible, but most inspectors do not consider it a reason to require suppression in a concealed space (as defined by NFPA 13, not 70).

 

[hillbilly1]

From what I have gathered over the years, it does burn, but is self extinguishing once heat is removed, also gives off toxic gases.