I need an interlock armored optical fiber cable for a plenum application. Can I use a riser rated cable on the inside as long as the outer jacket is plenum rated?

February 5, 2020

No. In a plenum space, not only does the entire interlock armored cable need to be plenum rated, but the inner component cable(s) must also be plenum rated. The NFPA does not allow the entire cable to be plenum rated – even if it passes the test at a nationally recognized test laboratory (NRTL) – if it has a riser cable on the inside. Further, the cable can’t be considered plenum rated because if the interlock armor is ever removed in a plenum space, the remaining component riser cable would be in violation of the NEC code.

If you have other questions concerning cable ratings, please call Technical Support at 877.263.2818 or via email.



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