Floor box outlets are a common method for terminating data, audio/video and power in commercial building construction. Conventional wisdom might lead one to assume that these installations would follow the same installation requirements as other cabling within the premises, however conduit placed in a concrete slab on or below grade is often susceptible to collecting moisture and should be treated as a “wet location” per NEC definition. CMR and CMP rated cables are not suitable for installation in wet locations. Even if the conduit systems are dried, experience has shown that they cannot be trusted to remain dry. Installation of Outside Plant (OSP) rated cable will make sure the installation meets code requirements and gives your installation years of reliable performance.
Using OSP Cable Indoors.
OSP cables are considered to be an “unlisted” communications cable, as such the cable is permitted in spaces other than risers and plenums within 50ft of its point of entrance, but must terminate or transistion to a “listed” cable if the cable run will exceed 50ft.