Broadband Applications & Construction Manual - Public - CommScope

Wiring Schemes
Commercial Installations 11.2
Wiring Schemes
A typical schematic for wiring a commercial installation is shown below. Coax cable transitions from the bonding
point into the basement of the building and is attached to a crossconnect, probably in a wiring closet. Taking
advantage of existing raceways and risers, riser-rated coax is pulled down the riser (or through the telecommunications
conduit) from the higher floors. There, it is connected to a distribution panel and the horizontal cable runs
are made.
On the third floor, plenum-rated cable is run through the ceiling spaces and dropped to the desktops through
custom raceways. It can also be dropped in the walls to outlets. On the second floor, CATV coax can be used to
run along the walls to outlets. It can be concealed with wiremold. On the first floor, a short run of CATV cable is
run behind the floor molding and carried across the floor, protected by a tread raceway.
Due to the length of the long run to the far end of the building, a high-performance cable such as riser-rated
QR ®
320, is run up and over from the wiring closet and
across the building via raceway or cable ladder. If it is in a
metal conduit, a cable with a lower fire rating may be used.
Avoid using plenum cables for longer runs as they tend to
attenuate faster.