I am installing a media enclosure in an under-stairway closet on my first floor. I plan on running Schedule 40 PVC conduit between the enclosure and the crawlspace directly below, as well as between the enclosure and the attic, via a penetration between floors. These conduits will all carry low voltage data cables, and one fiber cable from the crawl space. I plan on using fire rated foam to seal all of the annular space around the floor and ceiling penetrations.
I want to make sure I stay on the right side of the NEC, and would appreciate some help in interpreting the requirements I need to meet.
Article 800 covers data and network cable.
800.110 Raceways, Cable Routing Assemblies, and Cable Trays says...
Wires and cables shall be ... installed in raceways that comply with either...
Raceways Recognized in Chapter 3.
I prefer the Chapter 3 option, which then 352.30 further says:
PVC Conduit shall be installed as a complete system as provided in 300.18...
Raceways, other than busways or exposed raceways... ... shall be installed complete between outlet, junction, or splicing points prior to the installation of conductors.
It however goes further to say...
Exception: Short sections of raceways used to contain conductors or cable assemblies for protection from physical damage shall not be required to be installed complete between outlet, junction, or splicing points.
So, here are some of my questions:
- What would be considered a "Short" section of raceway? The vertical raceway going from my cabinet into the crawlspace is less than 3 feet at the moment. Does this count as short enough that I wouldn't need a "complete system"?
- If a complete system isn't necessary, can I just have the PVC Conduit sit flush with the wood in the crawlspace, or should the conduit extend a certain number of inches into the unfinished space before I cut it?
- If a complete system is necessary, is it enough for me to add just a box at the end of my PVC run in the crawlspace, leaving the actual box open so that fiber, coax, or ethernet cables can be fed into the conduit from the box?
- Is it okay to support this conduit with PVC hangers/straps if the penetration isn't close enough to a joist to secure it directly?
- Is there anything else I'm not thinking of that would fail me in an inspection?