Geez I just don't have the time to look it all up, but, the 2002 NEC 300.11 (A) talks about support and says that cables and raceways shall not be supported by ceiling grids. It also says you can install additional ceiling support wires for the sole purpose of supporting your cables, but, they must be attached at both ends. As I interpret this, we go in after the tgrid is done and install additional support wires, snap our supports on them if needed, then attach them to the grid. Some vendors offered tie wires that were painted a bright color to signify that these were not support wires for the tgrid, but for the cabling.
An inspector can't just say "I want it done this way" unless he can back it up.
Actually, he can, and he does. I performed fire inspections in another life as a fire marshal and yes, if I deemed the situation unsafe, I did not have to pass the installation. Let me tell you, there are many many more codes and references to pull from (Fire Life Safety Code) for example that may not apply to the construction phase of a project, but does when they want to actually occupy the building. The only thing that prevents an inspector from making up his own rules are challenges. I have personally challenged the local inspector three times by calling the state electrical inspector and won on two of them. These were times he said 'i want you to do it that way' and I said 'show me where I'm required to'. He bullied everyone else for years, it happens all the time.
Why do you think Chicago requires all RESIDENTIAL construction to be wired with conduit?
Not to say that lobbying isn't a tremendous force, the IBEW takes a fair amount of my money and I don't like them, but let's not forget the famous Chicago Fire (NOT caused by Mrs. Oleary's cow BTW) which quite likely prompted much of the code requirements there, as did the MGM Grand Hotel Fire in Las Vegas (another all conduit jurisdiction). Having studied fire codes for a few years in that former life, most fire/safety codes are build on experience. 492 people died in the Coconut Grove fire in Boston in 1942 mostly due to overcrowding and egress issues. The short story is what followed were major changes in the fire code regarding maximum occupancy and egress requirements. The NEC is a portion of the National Fire Code.
Daron J. Wilson, RCDD