CommScope Drop Cable - Manual (Page 51)

Multiple Story MDUs/Riser Installation
Multiple apartments, multiple floors, and the extra distances involved all contribute to the complexity of an MDU
installation. A helper is mandatory. A system designer will be required to specify whether and where line amplifiers
are needed. As always, make a thorough visual inspection of the proposed route and all outlet locations. It may
be that exterior installation is the only option; if so, see page 10.5.
Reaching the Crossconnect
The drop should be grounded outside like a residential installation (see section 7/Attaching to the ground block).
From here, a cable may be run to an exterior crossconnect or enter the building and attach to an internal cross-
connect that could be within a wiring or telecommunications closet. If you are using a powered cable (NEC 830)
you may run 50 feet (15 meters) into the building without using conduit; any longer distance requires the use of
metal conduit or placing cable within the wall.
Dropping Cable to the Closet
Check with the maintenance personnel of the building to locate any chases,
risers, ductwork or conduit being used by electrical wiring. DO NOT place
coax cable in the same conduit as electrical cable (unless it is a divided
conduit). In a riser, coax cable must be run at least 12 inches (30 cm) from
electrical wiring. Sometimes, elevator shafts can be used. The important
thing is to use 1) riser-rated cable and 2) a cable with the performance
required to carry the signal over the distance from closet to outlet. It could
be that you will need a higher performance cable for the interior installa-
tion than you used for the drop because of the longer internal installation
distance.
Set your cable reel or box near the riser entry point for the floor. Feed the
cable down to a helper at the base of the riser. A congested telecommu-
nications riser may require you to use fish tape to run the cable. See page
9.7 for specifics on using fish tape. Remember, you need to drop a cable
for each apartment, so make sure the riser can accommodate the total
number of cables you’ll be using.
Multiple Dwelling Units (MDUs) 10.4
Taller Buildings Outside