Separation Anxiety: Closing the Loop on Armored Cable

Reel Time August 2007, Cabling Business Magazine

Q: Whenever possible in a LANor data center environment, I specify armored fiber optic cable as the primary backbone because of its savings in space, and material and labor costs versus cable in conduit. But, I also know there is also a concern with extra steps needed for grounding and bonding, especially when separating the cable from the armored jacketing. Can you please provide further information?
A: Yes, armored cable has been gaining popularity because its construction combines ruggedness with space efficiency, resulting in lower cost of materials and installation, making it perfect for all premise environments – riser, plenum, indoor and outdoor, backbone and horizontal. Armored cable eliminates conduit, saving 25-50 percent in material costs. And when factoring the labor savings, as much as 80 percent can be saved over installing traditional fiber optic cables in conduit. However, there are unique methods for installing armored cables that must be followed.
As with all cable installations, following manufacturers’ installation guidelines will assure maximum performance and preserve cable life. For an armored cable, it is important to bond the armor as the armor is conductive and may provide a path for additional and unwanted electrical voltages. This could result in injury of personnel, as well as damage to electronic equipment.
The fiber optic cable itself and the outside protective interlocked armor are actually separate; they are not coupled together. The fiber optic cable “floats” within the armored sheath. Thus, both elements require connection to a pulling medium to prevent separation during installation.
Armored cable can be made easier to install and connect if it is manufactured as a trunk cable, with a pre-terminated ends and a factory installed pulling device. In any case, careful installation procedures must be followed using a properly installed pulling grip. Failure to do so may result in separation of the optical cable from the interlocking armor and elongation or unraveling of the interlocked armor.

To learn more about cable separation prevention, read the complete article, Separation Anxiety: Closing the Loop on Armored Cable