Rockwell Automation 1786-series ControlNet Fiber Media Planning and Installation Guide - Manual (Page 51)

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 51
Guidelines for Fiber-optic Installation Chapter 3
5. Use the following procedure if you must start cable placement in the
middle of a selected trenching route.
a. Pull in the first direction until the end point is reached.
b. Remove the cable for the opposite direction from the reel by hand and
carefully coil it on the ground in a figure-8 pattern.
c. Hand guide the cable in the second direction as the pull begins.
6. Begin cable placement as soon as possible after trenching.
You can avoid possible collapse and fill of your trench by filling it as soon as
possible. Depending on your application, you may want to use a trencher
with a mobile cable trailer and payoff.
7. Be certain that your cable trailer has properly sized rollers and an adjustable
breaking system.
8. Backfill over the cable as soon as possible after cable placement.
Consult your local ordinances for guidance on backfilling and trenching
procedures.
9. Avoid backfilling with materials like frozen earth, rocks and boulders,
construction debris, and so forth.
These objects could create point discontinuity along the buried cable and
harm the cable’s performance.
10. Machine tap any areas where trenching could be threatened by erosion
or washout.
11. Measure and record the optical cable attenuation and length by using
either an OTDR (optical time domain reflectometer) or an optical test.
12. Seal the ends of the cable with endcaps until they are terminated.
IMPORTANT Be certain to place the cable in a manner that will prevent the
cable from binding against foliage, rocks, or other impediments.
IMPORTANT Do not allow fiber-optic cable to be pinched, braided, or bent back
during payoff from the cable trailer. Do not exceed the cable’s
minimum bend radius and tension. You may even want to guide
your cable into the trench by hand.