I was getting ready to install some additional Cat 5e and Cat 3 cables at a local church. They are also in the process of upgrading their sound system, which includes building a new sound booth. Portions of the project are being inspected, so it is especially important that we all stick to code requirements.

The contractor installing the new cabling for the sound system mentioned to me that I should not be running PVC wire in the attic over the suspended ceiling of the main meeting room. He said new NEC requirements call for Plenum-rated CL3 cable (new improved heat tolerance?), and because I was not in conduit, this situation called for it. He said it was no different than running it exposed inside the room.

The material for the ceiling is sheetrock, suspended by wires, similar (only much larger) to those used for T-Bar. The ceiling space is not a true plenum. All HVAC is ducted, not using the ceiling space as a duct.

Am I missing something here? Is there something new I don't know about? Is there a stricter requirement because this ceiling is over a high occupancy (1200 person) room? I would be hanging the cable with cable hangers, so I was never planning to have cable laying directly on the ceiling. I was confused by what he said. Unless there is a local requirement, does anyone know of any other requirement to use Plenum, or specifically Plenum CL3 cable in a non-plenum ceiling space?

Thanks!