plenum rated cable tray cabling

[desertsparky]

I am doing an install at a data center and the prints indicate that I am to use a plenum rated liquid tight raceway. This raceway is to go into a cable tray under the raised floor. I found liquid tight that is under floor rated, but not plenum and cable tray rated. I am not allowed to use AC or MC cable. Is there anything that meets the requirements of being under a raised floor, plenum rated, and cable tray rated? AC and MC cable is the closest that I have found.

 

[don_resqcapt19]

I am not aware of a requirement that flexible conduit has to be rated for installation in cable tray. You just have to find some that plenum rated.
Take a look at this one

 

[jusme123]

http://www.metalhose.com/products/FMT.html

USES:

International Flexible Metallic Tubing is a raceway for electric conductors that is circular in cross section, flexible, metallic and liquid-tight without a nonmetallic jacket. Lengths in use are limited to 6 feet. For use in dry and accessible locations where protected from physical damage or concealed in ductwork or plenums, such as above suspended ceilings; for 1000 volts maximum; and in branch circuits.

 

[don_resqcapt19]

http://www.metalhose.com/products/FMT.html

USES:

International Flexible Metallic Tubing is a raceway for electric conductors that is circular in cross section, flexible, metallic and liquid-tight without a nonmetallic jacket. Lengths in use are limited to 6 feet. For use in dry and accessible locations where protected from physical damage or concealed in ductwork or plenums, such as above suspended ceilings; for 1000 volts maximum; and in branch circuits.

That is the product covered by Article 360 and cannot be used in lengths exceeding 6'.

 

[ron]

I am not aware of a requirement that flexible conduit has to be rated for installation in cable tray. You just have to find some that plenum rated.
Take a look at this one

Don,
Although the blue stuff is "suitable for use in raised computer room floors" according to the manufacturer, I don't think it is plenum rated.

The blue stuff is often used in conjunction with 645.5(D)(2), but requires compliance with 645.4. It cannot be used for 300.22(C)(1) where the room is not 645 compliant.

 

[don_resqcapt19]

Good point Ron. I guess I should have read the specs closer.

 

[suemarkp]

Can you get him to give on the liquid tight requirement? Seems unnecessary if the cable tray is above the floor at all. Then normal FMC would work just fine.