Installing Optical Cable

The general process of installing optic cable is much like that of pulling electrical cables: Cables are pulled into raceways using lubricant and a pull line.
Of course, just as there's more than that to pulling electrical cables, there's more to installing fiber. Here's a look at some techniques unique to fiber and some tips for getting the job done right:

Connect the strength member of the cable to the pull line. Unless cables are designed for such use, basket grips and similar methods of attachment should not be used.

Use a swivel while pulling to prevent the cable from being twisted by rigid attachment to a fish tape. To keep pulling tension within careful limits, do not use power pullers with fiber, unless you use a tension meter as well. As a general rule, the tension
should not exceed 300 pounds with indoor cables and 600 pounds with outdoor cables. But always check the specifications for the cable to be sure.

Use lots of large pull boxes and divide pulls in half or even thirds at corners or pull boxes. A pulling operation must be stopped if pulling tensions reach the cable's limit. The discontinued pull will have to be aborted, the cable pulled back out and replaced on the reel, and the pull started again using shorter runs, better lubrication, or both. The cable may be reused if the pull or extraction has not damaged it.

Identify exact terminating locations in advance, keeping in mind that the cable must be pulled all the way to where it will be terminated, not just into the room. This obvious though often overlooked step can lead to costly mistakes if forgotten.

Carefully measure the cable's path before the conduit pull to avoid the need for splices. Not only do splices cost time and money, but they also cause loss in both signal quality and strength. In fact, most designers specify point-to-point or device-to-device runs to avoid needless signal loss from splices.
The preferred way to measure is to use a pull tape. This product, sometimes called mule tape, is a flat ribbon, consecutively numbered in feet, which is usually made of polyester or aramid yarn and may be coated with plastic for waterproofing. It comes in different lengths and pull strengths.
Pull the pull tape into the conduit, or along the cable path, for an initial measurement, and add to that extra length for splices, terminations, and future access coils, if specified. The amount of additional cable needed for splicing depends on site conditions, splicing method used, and long-range plans for cable usage. For termination length, figure on about 2 to 3 meters of additional cable beyond where the terminal will be mounted. And add about 10 to 12 meters per span for any access or repair coils. A good rule of thumb to cover all these additional cable lengths is to allow I percent extra for outside plant (outdoor) cable runs and 5 to 7 percent extra for inside cable runs.

Choose crews based on the length of the pull, total degrees of bend, tail loading (force required to pull cable off feed reel), use of lubricant, and use of power putting equipment. In most cases, two- or three-person crews are ideal. That way, one person pays the cable off the reel and into the duct, while one or two others pull at the other end.



Source:www.elec-toolbox.com/communications/classifications/fiber/fiber.htm