Information Technology Reference
In-Depth Information
The Tubing Pull
In some ways, it is impossible to predict every twist and turn technology will make.
It would be nice to have some way of replacing the wiring periodically if needed.
You might need to upgrade to fiber-optic cable.
Maybe each workstation will need another cable and outlet to add an applica-
tion such as video. What if you could simply go to the telecommunications room
and pull in some new cable?
It may be possible to do just that. A technique that works well in closed-ceil-
ing buildings can also be extended to conventional grid-ceiling buildings. As the
building is constructed, continuous plastic tubing home runs are made from the
telecommunications room to a flushmounted outlet box at each workstation. A pull
string may be blown through the tube, or pulled in with a snake. The cable is then
pulled through the tubing to the outlet and terminated normally on both ends. As
needs change, new cables are pulled through the tube using the old cable as a pull
string. One type of compatible tubing is called “3/4 Flex” in the electrical trades.
Another thinner tubing is used in so-called blown-in fiber installations.
This method works very well in closed construction, which is very expensive
to rewire. It also works in smaller offices, where the cable runs are not too long. It
may have a special advantage for Category 5e/6/AC6/7 runs, as it avoids the per-
formance-robbing problems of kinks, minimum bend radius, tight tie-wraps, and
metallic runs along pipes and structural steel.
