Which statement accurately describes optical fiber circuits in composite cables with power circuits under 600V?

Which statement accurately describes optical fiber circuits in composite cables with power circuits under 600V?

• A. Optical fiber circuits are prohibited in composite cables with power circuits under 600V.
• B. Only shielded optical fibers may be used.
• C. Optical fibers are permitted.
• D. Optical fibers require a separate enclosure.

Answer: (C)

Optical fiber circuits are permitted in composite cables that also carry power under 600V because fiber is nonconductive and is treated as a communications medium rather than a power conductor. The NEC allows fiber-optic cables to share a jacket with power conductors if the assembly is listed for that use and installed according to its listing. This means there’s no blanket prohibition, and there’s no requirement that the fibers be shielded or placed in a separate enclosure solely due to the presence of power conductors under 600V. Just follow the listing and any separation or routing requirements in the applicable code sections to ensure safe, compliant installation.

Optical fiber circuits are permitted in composite cables that also carry power under 600V because fiber is nonconductive and is treated as a communications medium rather than a power conductor. The NEC allows fiber-optic cables to share a jacket with power conductors if the assembly is listed for that use and installed according to its listing. This means there’s no blanket prohibition, and there’s no requirement that the fibers be shielded or placed in a separate enclosure solely due to the presence of power conductors under 600V. Just follow the listing and any separation or routing requirements in the applicable code sections to ensure safe, compliant installation.