Plenum vs. PVC

[corcoran]

I was told that we are required to run plenum CAT 5e and RG-6 cable for a residential high rise project instead of pvc because the building is more than 5 stories tall. This is for the low voltage cable and telephone cabling within the individual units, not riser. As I understand it plenum wire is only required if the space above the ceiling is used for air return, which in this case it is not. Is this incorrect?

[tom baker]

Yes basically, but there is another class of cable called riser. But plenum cable is not that much more. This may be a local requirement. The cable types and permitted subsitutions are in NEC Article 800.

[hbiss]

Yes, must be a local requirement. I also can't see why you would need to use CAT 5 for voice wiring especially since there is no reason to believe this is all it will ever be used for. The cost difference between CAT 3 and CAT 5 plenum is significant.

I say use whatever is right for the use today. Trying to ward off future obsolescence is just wasting money because this stuff becomes obsolete so quickly.