Support and Secure for cabling

[eatapeach]

Trying to figure out if an independent support wire is used to support cable shall it it be secured at each end and what does secure at each end mean? Attached to structure and the ceiling grid?

300.11 Securing and Supporting.

(B) Wiring Systems Installed Above Suspended Ceilings. Where independent support wires are used, they shall be secured at both ends. Cables and raceways shall not be supported by ceiling grids.

(2) Non–Fire-Rated Assemblies. Wiring located within the cavity of a non–fire-rated floor–ceiling or roof–ceiling assembly shall not be secured to, or supported by, the ceiling assembly, including the ceiling support wires. An independent means of secure support shall be provided and shall be permitted to be attached to the assembly.

The 2017 Commentary states this:
Independent support, and securing both ends of the support wire, do preclude a connection to the ceiling grid on one end.The word Preclude basically means makes it impossible so which is it ? Secure both ends or is it impossible? How would it be secure if you didn't attach it to the grid?

 

[LarryFine]

Trying to figure out if an independent support wire is used to support cable shall it it be secured at each end and what does secure at each end mean? Attached to structure and the ceiling grid?

The answer to this has always been yes. It means the wiring cannot simply gang from a single support point. You could support from above and one side.

The 2017 Commentary states this:
Independent support, and securing both ends of the support wire, do preclude a connection to the ceiling grid on one end.The word Preclude basically means makes it impossible so which is it ? Secure both ends or is it impossible? How would it be secure if you didn't attach it to the grid?

I interpret this to mean that one end can connect to the grid, just both ends cannot. It would be difficult to not involve the grid when away from any walls.

 

[eatapeach]

I agree Larry. I had a Fire Marshall reject my interpretation for the fire alarm cable. He will not allow the #12 gauge wire to be tied to the ceiling grid. His interpretation of support is the cable passing through the J hook secures that end. I tried to explain to him if the owner ever has to pull additional cable it would be impossible.

I confirmed with the ceiling manufacture (USG) that they didn't have an issue with tying to their assembly and they stated no problem.

I am thinking I will ask NFPA for a written interpretation of this code section.

Thanks