What Is Armored Fiber Cable?
As is known, armored fiber cable can provide extra protection for fiber optic cable without sacrificing flexibility or functionality within fiber networks, featuring more robust and reliable when encountered with rodents, moisture, and other issues that may cause damage. The armored fiber cable is now optimal for campus & building backbones, data centers, and industrial applications. Therefore, using armored fiber optic cable will greatly reduce the cost of unnecessary cable loss. This article will lead you to know this armored optical cable.
Armored Fiber Cable Basics
Armored fiber optic cables are much stronger and tougher than common cables, which are designed to withstand crush, pressure, and rodent issues. They possess high flexibility and durability when used in harsh environments or limited space.
When it comes to unarmored and armored fiber optic cables comparison, the distinctive difference lies in the outer protective layer. Precisely speaking, the armoring material doesn't have to be metal, which can be fiber yarn, glass yarn, polyethylene, etc. The additional outer protective layer for optical cable makes the armored cable special, so the armored cables will be installed in locations that may expose to mechanical damages, while unarmored cables are normally used for control systems.
Structure of Armored Fiber Optic Cable
Armored fiber optic cable has some basic layers. The first layer is the outer jacket made of plastic materials. It can protect the cable from the destroy of solvent and abrasion. The second layer under outer jacket is the strength member made of armored materials, such as aluminum foil, steel and kevlar. These materials are difficult to cut, bite and burn which are great protections for the optical cable. Next is the inner jacket of fiber made of protective and flame-retardant materials to support the internal optical fibers.
Armored vs. Non-Armored Fiber Optic Cable
In this post we will discuss armored and non armored fiber optic cable and the various cable constructions that are offered. I will also talk about the advantages and disadvantages of armored versus non armored cables for these various constructions.
Fiber optic cable is offered with two different types of armor – aluminum interlocking armor for indoor cables and corrugated steel tape for outdoor cables. The armoring offers an added layer of mechanical protection to the cable. The differences between the two types of armor are the material that the armor is made of and the way it is applied to the cable. Aluminum interlocking armor is made of – you guessed it – aluminum – and it is wrapped helically around the fiber cable. This type of armor is used in indoor rated cables. The second kind of armor is corrugated steel tape. This armor is composed of coated, corrugated steel and it is folded
longitudinally around the cable. Corrugated steel tape is found in outdoor rated cables. Fiber optic cables are offered in many different cable constructions, each with their own advantages and disadvantages. Armored cables have some benefits when you are installing them, and there are applications where it will be more cost effective to use this kind of cable. Some of these cables are more versatile than others, and if you have some on hand, it may help you to be ready for any situation (like an unexpected network outage). Other times the decision will come down to the engineer and the type of cable they prefer for the job. There are costs associated that can help you make the decision about the style you choose. Armored cable costs more than non-armored, but the labor to install it may be a less expensive, and this could make it more feasible to install armored cable. Below we will discuss a few different cable constructions and where you can pick between the two, armored versus non armored.
Distribution Cable
Distribution Cable is a tight buffered cable construction; inside of the outer jacket is a layer of aramid yarn and multiple fibers with 900um tight buffer jackets. Distribution cables are multi fiber cables that are used for indoor applications. The color of the outer jacket for single mode is typically yellow and for multimode the outer jacket can be orange, aqua, magenta or lime green depending on the multimode fiber type. Having a 900um jacket on the fibers allows you to be able to terminate a connector without having to do a build up on the fiber. Where this cable is being run indoors will help to determine if armor is needed. When fiber optic cable is being run in harsh environments or high traffic areas, it would be good to have the extra protection of the armored cable. This may be in a warehouse environment or it may be above a ceiling that is accessed regularly. Indoor armored cable uses an aluminum interlocking armor that helps to protect the fiber cable, along with increasing the durability of the fiber run. Sometimes you may be required to run cable in conduit indoors. The aluminum interlocking armored cable can help eliminate the need for conduit and it can be substituted for running conduit. Installing conduit can increase the cost of the installation because you have to spend time to place the conduit. Then you have to pull the cable through the conduit which means you have essentially doubled the labor costs to perform the installation. When using the aluminum interlocking armor cable, you now just have to pull your cable once. When running the armored cable in a cable tray or under a floor or through a ladder rack - any location where it will be installed and is not likely to be touched or disturbed then you probably do not have to use armored cable.
Indoor Outdoor Cable
Another style of cable that offers an armored or non-armored construction is Indoor Outdoor Cable. This type of cable typically has a black UV resistant outer jacket as well as moisture blocking material in the Kevlar or aramid yarn of the cable. There are two different types of indoor outdoor cable that you can use. One is known as distribution style and it will have 900um tight buffer like the indoor distribution cable we talked about above. Indoor/Outdoor distribution is the same construction as the above mentioned distribution cable, except it has a special black UV rated jacket to protect the fibers inside from the sun’s rays.
Indoor Outdoor is also available as a Dry Loose Tube construction. This is where the fibers have a 250um acrylate coating only, and they are arranged in separate buffer tubes with 12 color coded bare fibers in each tube. These are similar to the next category - Outside Plant Cable, but they do not contain any water blocking gel, hence the name “Dry”. Similar to the distribution style cable, this type of cable can be armored or non-armored. The armor used in the cable is aluminum interlocking armor. This type of cable cannot be direct buried, but the armor gives the fiber some extra protection in rugged environment settings. Oftentimes installers will use this when they need to run indoors and some distance outdoors as well. Rather than needing an interconnect box at the building entrance to transition from outdoor to indoor cable, this type of cable can be run in conduit outdoors and then be brought inside without transitioning to an indoor rated cable.
This type of non-armored cable can be used in multiple applications because it is so flexible in the ways that it can be deployed. Since you can run this cable inside or outside, some contractors will purchase this type to keep on hand because they can use it for a variety of applications. This allows them the flexibility to handle multiple situations without having to carry several different spools of cable.
Outside Plant Cable is a cable construction that typically has gel or Icky Pic coating the bare fibers to give it extra water blocking protection. OSP cables are run either underground or in aerial applications. These gel filled cables can only be run inside a building up to 50 feet because of the toxicity of the fumes and smoke produced when it burns. Building codes regulate this distance and the cable run will need to be inspected once it is installed. The way that this cable is installed will help to determine if you will need armor or not. Aerial and buried applications can use either armored or non-armored outdoor fiber optic cable. Here we will focus on when the cable is buried in the ground.
When you talk about outside plant cable being buried, you have a couple options as to how you can accomplish the installation. The first option has to do with non-armored cable and involves the use of conduit or innerduct. When you are running conduit underground an armored fiber is not needed but can be used if desired, because it will give the cable extra ruggedness and it will help with locating the cable later.
Armored outside plant cable is made so that it can be direct buried and it does not require the use of conduit. This type of cable construction uses corrugated steel tape for the armoring. When you bury the cable, please know how deep the frost line is in the area where you are located because the cable will need to be buried below that line. The cable is buried below the frost line so it isn’t damaged when the ground freezes and “frost heaves”. Not only is armored cable suitable for direct burial, it is also used for rodent protection. So if you have rodent trouble, it would be wise to use the armored cable. Keep in mind that the armored cable will need to be bonded and grounded for protection from lightning strikes, especially when it is used for an aerial application.
What does bonding and grounding the cable do? Basically, bonding and grounding an armored fiber optic cable protects the cable and the equipment that it connects to from electrical currents such as current from faulty or exposed wiring or lightning strikes.
Armored Fiber Cable Types
The armored fiber cables can be classified into several types in terms of different classifications, which includes the type of metal tube within the cable, the installation methods of the cable, and the specific applications.
Classification According to Metal Tube
Armored fiber optic cable can be divided into two types according to the metal tube: interlock armored fiber cable and corrugated armored cable. Interlocking armor is an aluminum armor that is helically wrapped around the cable and found in indoor and outdoor cables, which offers ruggedness and superior crush resistance. Corrugated armor is a coated steel tape folded around the cable longitudinally, which can be found in outdoor cables and offers extra mechanical and rodent protection. Both armored fiber cables enable installation in the most hazardous areas, including environments with excessive dust, oil, gas, moisture, or even damage-causing rodents.
Interlock Armor vs Corrugated Armor.
Classification According to the Installation Method
As mentioned before, there is a strong metal armored tube inside the armored fiber cable. Therefore, the termination of the armored fiber cable is more difficult than that of standard fiber optic cables. Field-terminated armored fiber cables have better performances in some outdoor applications, while pre-terminated ones are adopted by many installers for indoor applications considering quality transmission and time-saving factors.
Furthermore, the pre-terminated armored fiber cables provided by the market are mainly armored fiber patch cable and armored fiber trunk cable: the former is stronger and more flexible than the traditional fiber patch cable, while the latter is a length of armored fiber cable with several legs on each end terminated with fiber optic connectors.
Amored fiber patch cable & Amored trunck cable.
Classification According to Application
Armored fiber cable can be used for indoor and outside plant (OSP) applications. According to different installation environments, tight-buffered armored cable and loose-buffered armored cable are generally adopted: Both loose-buffered and tight-buffered armored fiber cable can fit indoor and outdoor applications, but loose-buffered ones are more often used in outdoor applications.
Indoor Armored Fiber Cable: The armored cable used for indoor applications often consists of tight-buffered or loose-buffered with strength members and an inner jacket. The inner jacket is commonly surrounded by a spirally-wrapped interlocking metal tap armor. Typical indoor armored fiber cable types include GJFJV, GJFJZY, GJFJBV, GJFJBZY, GJFDBV, and GJFDBZY. With the fast development of fiber optic communication technology and the trend of FTTX, the demand for installing indoor fiber optic cables between and inside buildings is fast-growing.
Outdoor Armored Fiber Cable: Armored cable for outdoor is designed to ensure operation safety in complicated outdoor environments, and most of them are loose buffer designs. Light armor and heavy armor are the two versions of outdoor armored fiber optic cable. The light armored cable possesses the protective plastic jacket with the same durability and longevity of a stainless steel cable but in a lighter weight, which is suitable for a myriad of applications from interconnects to industrial and semi-harsh environment conditions. The heavy armored cable is wrapped in a wire circle that can protect the fibers from gnawing animals and damages that occur during direct burial installations, which is applied for the river bed and ocean floor.
Armored Fiber Cable Types
The armored fiber cables can be classified into several types in terms of different classifications, which includes the type of metal tube within the cable, the installation methods of the cable, and the specific applications.
Classification According to Metal Tube
Armored fiber optic cable can be divided into two types according to the metal tube: interlock armored fiber cable and corrugated armored cable. Interlocking armor is an aluminum armor that is helically wrapped around the cable and found in indoor and outdoor cables, which offers ruggedness and superior crush resistance. Corrugated armor is a coated steel tape folded around the cable longitudinally, which can be found in outdoor cables and offers extra mechanical and rodent protection. Both armored fiber cables enable installation in the most hazardous areas, including environments with excessive dust, oil, gas, moisture, or even damage-causing rodents.
Interlock Armor vs Corrugated Armor.
Classification According to the Installation Method
As mentioned before, there is a strong metal armored tube inside the armored fiber cable. Therefore, the termination of the armored fiber cable is more difficult than that of standard fiber optic cables. Field-terminated armored fiber cables have better performances in some outdoor applications, while pre-terminated ones are adopted by many installers for indoor applications considering quality transmission and time-saving factors.
Furthermore, the pre-terminated armored fiber cables provided by the market are mainly armored fiber patch cable and armored fiber trunk cable: the former is stronger and more flexible than the traditional fiber patch cable, while the latter is a length of armored fiber cable with several legs on each end terminated with fiber optic connectors.
Amored fiber patch cable & Amored trunck cable.
Classification According to Application
Armored fiber cable can be used for indoor and outside plant (OSP) applications. According to different installation environments, tight-buffered armored cable and loose-buffered armored cable are generally adopted: Both loose-buffered and tight-buffered armored fiber cable can fit indoor and outdoor applications, but loose-buffered ones are more often used in outdoor applications.
Indoor Armored Fiber Cable: The armored cable used for indoor applications often consists of tight-buffered or loose-buffered with strength members and an inner jacket. The inner jacket is commonly surrounded by a spirally-wrapped interlocking metal tap armor. Typical indoor armored fiber cable types include GJFJV, GJFJZY, GJFJBV, GJFJBZY, GJFDBV, and GJFDBZY. With the fast development of fiber optic communication technology and the trend of FTTX, the demand for installing indoor fiber optic cables between and inside buildings is fast-growing.
Outdoor Armored Fiber Cable: Armored cable for outdoor is designed to ensure operation safety in complicated outdoor environments, and most of them are loose buffer designs. Light armor and heavy armor are the two versions of outdoor armored fiber optic cable. The light armored cable possesses the protective plastic jacket with the same durability and longevity of a stainless steel cable but in a lighter weight, which is suitable for a myriad of applications from interconnects to industrial and semi-harsh environment conditions. The heavy armored cable is wrapped in a wire circle that can protect the fibers from gnawing animals and damages that occur during direct burial installations, which is applied for the river bed and ocean floor.
Advantages of Armored Fiber Optic Cable
There are numerous advantages of armored fiber optic cable. The flexibility and durability of armored cable are excellent which makes it the right choice for industrial purposes. Moreover, the armor materials protect the cable from damage caused by animal, human or harsh environment, thus it can be applied to places where ordinary cables can not. The armored cable can also undergo heat and high pressure of extreme conditions. Using the armored optical cable not only ensures the high speed data transmission, but also extends the life span of cables.
Armored Fiber Cable Installation Guide
Armored fiber optic cable caters to both the rigorous environment of the outdoor but also can be routed indoors. Despite the numerous benefits armored fiber cable retains, it also yields some inconvenience to bond and ground the cable. To handle the problem that may occur during the installation, wisely perform the following steps.
Bend Cable—Bend the armored cable about 10 inches from its end and squeeze with your hand until the coils of the armor come apart. If you can't do this by hand, use pliers, or employ another cutting method.
Twist Cable—Firmly grip the armored cable on each side of the cut and twist until the split-apart armor coil pops out, away from the wires. Use two pairs of pliers if you can't do this by hand.
Cut Exposed Coil—Using side cutters, cut the exposed coil of sheathing. You may have to grab the coil with the side cutters and work it back and forth to open and make the cut.
Cut the Wires—If you are cutting a piece to length, slide back the sheathing and cut through the wires. Otherwise, slide the waste piece off and throw it away.
Remove Excess—Cut off any sharp points of sheathing using side cutters. Remove the paper wrapping and any thin plastic strips.
Summary
When fiber optic cables are needed for terrible conditions, a strong protection for the cable is very necessary. Therefore, to secure the data communication, armored fiber optic cable is a good solution to make the cable free from different damages. But when you operate the armored cables, you must be careful of the freshly cut edges which are very sharp to cope with. And the budget of your project should also be taken into consideration as armored cables are generally more expensive than the common ones.
