Armored fiber optic cables are often installed in a network for added mechanical protection, as they have extra reinforcing in the cable housing to prevent damage. Two types of armored fiber optic cables exist: interlocking and corrugated. Interlocking armor is an aluminum armor that is helically wrapped around the cable and found in indoor and indoor/outdoor cables. It offers ruggedness and superior crush resistance. Corrugated armor is a coated steel tape folded around the cable longitudinally. It is found in outdoor cables and offers extra mechanical and rodent protection.
The Structure of an Armored Fiber Optic Cable
In basic armored fiber cable designs, the outer sleeve provides protection against wind, solvents, and abrasion. This outer sleeve is usually made of plastic such as polyethylene. The next layer between the sleeve and the inner jacket is an armoring layer of materials that are difficult to cut, chew, or burn, such as steel tape and aluminum foil. This armoring material also prevent the fiber from being stretched during cable installation. Ripcords are usually provided directly under the armoring and the inner sleeve to aid in stripping the layer for splicing the cable to connectors or terminators. The inner jacket is a protective and flame retardant material to support the inner fiber cable bundle. The inner fiber cable bundle includes strength members, fillers and other structures to support the fibers inside. There are usually a central strength member to support the whole fiber cable.
There are several potential jacket materials are considered for armored indoor outdoor cable. The choice of jacket material depends on the required level of flame retardance in the final cable, including Polyvinyl Chloride (PVC) jacket, Halogen Free Polyolefins (HFPO) and Coated Steel Armor. Armored cable is also available with a double-armor protective jacket for added protection in harsh environments. The steel armor should always be properly grounded to an earth ground at all termination points, splice locations and all building entrances.
Benefits of Installing Armored Cable
During some fiber optic installations, there is a need to provide extra protection for the cable due to the installation environment. That environment may be underground or in buildings with congested pathways. Installing an armored fiber-optic cable in these scenarios would provide extra protection for the optical fiber and added reliability for the network, lessening the risk of downtime and cable damage due to rodents, construction work, weight of other cables and other factors.
But one inconvenience is the need to bond and ground the cable. This inconvenience can be eliminated by using a dielectric-armored cable. Dielectric-armored cable options exist that offer the required protection without the hassle of grounding and bonding the armor, or the extra steps of installing a conduit and cable when the cable is without any armored protection.
Compared with Other Common Fiber Optic Cables
These armored fiber optic cables are the same diameter with commonly seen 2mm O.D or 3mm O.D cables, and their optical performance is also same as the common fiber optic cables. The difference is armored fiber cables are with stainless steel armor inside the cable jacket and outside the optical fiber, this stainless steel armor are strong enough to make the cables anti-rodent and the whole cable can resist the steps by an adult people.
Armored fiber optic patch cables are also can be single mode and multimode types, the connectors optional including commonly used LC, SC, ST, FC, E2000, MU, SMA, etc. Cable structure can be simplex, duplex or multi-fiber types. Armored fiber cables from fiber-mart.com can be with custom made colors and cable length, they are manufactured according to industrial and international standards.