Information Technology Reference
In-Depth Information
FIGURE 11.10
Innerduct is used to protect fiber runs.
radius, without collapsing the interior, as a smooth tube would. The ribbed con-
struction also provides mechanical strength against crushing. Innerduct may be
placed inside larger structures called
ducts
that are basically round or square pipes
that run between buildings. The innerducts are used to subdivide each section of the
larger duct, and also to provide additional protection of fiber cable that is run
through the duct.
Innerduct is an obvious choice for riser cables between building floors or
between TRs on the same floor. Innerduct is also very useful for the horizontal run
between a TR and a consolidation point. An innerduct may also be used in a cable
tray to isolate fibers from copper cables. A major advantage of innerduct is that it
can be installed before any fiber is run. So, you can simply route the innerduct to
wherever the fiber needs to go and later pull the fiber in and terminate it. This pre-
vents possible damage to pulled fiber during new construction build-out. As with all
cabling components, innerduct must meet all the proper ratings to be placed in
plenum space.
Cable trays are used to help organize and protect cabling infrastructure in hori-
zontal runs. They may be used in any size installation, but are often found in large
buildings. They serve to protect all types of cable, but are very useful as an alternative
to cable “hangers” that place hundreds of bends in cable runs. The cable lies flat in
the tray and is easily pulled straight across long distances without the need for special
devices such as pulleys. Additional cable is easily placed in the trays, as needed. Cable
trays are virtually mandatory in medium to large TRs. Trays are available in plastic or
