How To Install Outdoor Fiber Optic Cables In Underground Ducts And Innerducts

by http://www.fiber-mart.com

Fiber ducts are usually made from HDPE (high-density polyethylene), PVC or other compound. They are usually in black or gray. Fiber innerduct is usually orange or yellow.
:: Why usually fiber ducts and innerducts are corrugated?
Fiber ducts and innerducts are corrugated to provide the following benefits:
1. Decreasing pulling tensions during installation
2. Very flexible and can be used in installation locations where many turns are involved
3. After installation, corrugated innerduct should be left for a day to allow the innerduct to retreat back into the duct through its corrugated spring action
:: The use of pulling tape
Fiber optic cable pulling tape is preinstalled in fiber duct and innerduct in the factory. This saves significant time during the installation process. Duct and innerduct can also be pre-lubricated in the factory, thus significantly reduces pulling tensions.
:: Never bend over its minimum bend radius
Just like fiber optic cable, fiber duct and innerduct also have a minimum bend radius spec. Never ever should the duct or innerduct be bent tighter than its minimum bend radius.
:: What is supported radius?
The supported radius is the minimum bend radius when the duct is bent around a supporting structure such as in another duct or on a reel.
:: What is unsupported radius?
The unsupported radius is the minimum bend radius when the duct has no supporting structure in the bend.
Duplex OM1 62.5/125 Multimode Fiber Optic Patch Cable
:: Benefits of using fiber duct
Fiber duct protects the fiber cable and also provides an opportunity for future cable access and expansion. Fiber optic cable can be pulling into existing duct. The duct should usually be oversized to allow future cables be pulled in.
:: Benefits of using fiber innerduct
Fiber innerduct provides protection for the fiber cable from being disturbed by other companies’ cable installation operation. It also provides extra protection from the environment. Or fiber innerduct can be used in old duct installation.
:: Things to keep in mind
1. Install end plugs
After the fiber optic cable is installed into a duct or innerduct, end plugs should be installed to provide a water seal. No debris should be able to enter the duct or innerduct, and watertight should always be maintained for the duct or innerduct.
2. Duct and innerduct should be properly sized for future expansion possibility
As always, planning for future expansion is crucial for real successful projects. A maximum of 40% fill ratio is a good practice to follow. The duct size should be increased for long installation lengths with many turns. A larger duct can help to reduce cable-pulling tensions. Standard duct sizes vary from 3 to 8 inch ID and innerduct sizes vary from 0.75 to 2 inch.
:: The benefit of using duct lubricant
Duct lubricant can significantly reduce the cable’s coefficient of friction, thus lessening the pulling tension during cable pulling process. This is especially important in long cable duct pulls and pulls with many turns.
Duct lubricant spillage should be cleaned up as soon as possible to prevent accident since it is very slippery. Manufactures’ recommended procedure for cleaning lubricant provides good instruction on how to do the cleaning.
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Typical Outdoor Fiber Optic Cables

by http://www.fiber-mart.com

Fiber optic cable provides protection for the fibers from the environment encountered in an installation. Outdoor Fiber Cable is designed strong to protect the fibers to operate safely in complicated outdoor environment, it can be buried directly, pulled in conduit, strung aerially or even placed underwater. While indoor cables don’t have to be that strong.
Outdoor fiber optic cable is composed of many fibers enclosed in protective coverings and strength members. Common features for fiber optic cable include polarization maintaining, graded index, and metalization. Most outdoor fiber cables are loose buffer design, with the strengthen member in the middle of the whole cable, the loose tubes surround the central strength member. Inside the loose tube there is waterproof gel filled, whole cable materials used and gels inside cable between the different components will help make the whole cable resist of water.
Typical outdoor fiber optic cable types are used for aerial, direct buried and duct applications.
Loose Tube Cables
Loose Tube cables are the most widely used cables for outside plant trunks, as it can be made with the loose tubes filled with gel or water absorbent powder to prevent harm to the fibers from water. Loose Tube Fiber Optic cables are composed of several fibers together inside a small plastic tube, which are in turn wound around a central strength member and jacketed, providing a small, high fiber count cable. They can be installed in ducts, direct buried and aerial/lashed installations for trunk and fiber to the premise applications. Loose tube cables with singlemode fibers are generally terminated by spicing pigtails onto the fibers and protecting them in a splice closure. Multimode loose tube cables can be terminated directly by installing a breakout kit, also called a furcation or fan-out kit, which sleeves each fiber for protection.
Ribbon Cable
Ribbon cable is preferred where high fiber counts and small diameter cables are needed. This cable has the highest packing density, since all the fibers are laid out in rows in ribbons, typically of 12 fibers, and the ribbons are laid on top of each other. Not only is this the smallest cable for the most number of fibers, it’s usually the lowest cost. Typically 144 fibers in ribbons only has a cross section of about 1/4 inch or 6 mm and the jacket is only 13 mm or 1/2 inch diameter! Some cable designs use a “slotted core” with up to 6 of these 144 fiber ribbon assemblies for 864 fibers in one cable! Since it’s outside plant cable, it’s gel-filled for water blocking or dry water-blocked. These cables are common in LAN backbones and data centers.
Armored Fiber Optic Cable
Armored cable is used in direct buried outside plant applications where a rugged cable is needed and/or for rodent resistance. Armored cable withstands crush loads well, for example in rocky soil, often necessary for direct burial applications. Cable installed by direct burial in areas where rodents are a problem usually have metal armoring between two jackets to prevent rodent penetration. Another application for armored fiber optic cable is in data centers, where cables are installed under the floor and one worries about the fiber cable being crushed. This means the cable is conductive, so it must be grounded properly.
A Pair of 10/100M Single Fiber 1-port SC/ST/FC & 1-port RJ45 BIDI WDM Fiber Media Converter
Aerial Fiber Optic Cable
Aerial cables are for outside installation on poles. They can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. A widely used Aerial Cable is optical power ground wire (OPGW) which is a high voltage distribution cable with fiber in the center. The fiber is not affected by the electrical fields and the utility installing it gets fibers for grid management and communications. This cable is usually installed on the top of high voltage towers but brought to ground level for splicing or termination.
Indoor/Outdoor Cables
Fiber Optic Indoor/Outdoor Cables are designed to meet both the stringent environmental requirements typical of outside plant cable AND the flammability requirements of premise applications. Ideal for applications that span indoor and outdoor environments. By eliminating the need for outside to inside cross-connection, the entire system reliability is improved and with lower overall installation costs.
Underwater and Submarine Cables
It is often necessary to install fibers under water, such as crossing a river or lake where a bridge other above water location is not possible. For simple applications a rugged direct burial cable may be adequate. For true undersea applications, cables are extremely rugged, with fibers in the middle of the cable inside stainless steel tubes and the outside coated with many layers of steel strength members and conductors for powering repeaters. Submarine cables are completed on shore, then loaded on ships and laid from the ship, often while operational to ensure proper operation.
FiberStore offers a comprehensive range of multimode fiber cable and single-mode fiber optic cables. Indoor, outdoor, armoured, tight buffered or loose tube structures, which cover all possible applications.

The types of Outdoor Fiber Optic Cables

by http://www.fiber-mart.com

Fiber optic cable provides protection for the fibers from the environment encountered in an installation. Outdoor Fiber Cable is designed strong to protect the fibers to operate safely in complicated outdoor environment, it can be buried directly, pulled in conduit, strung aerially or even placed underwater. While indoor cables don’t have to be that strong.
Outdoor fiber optic cable is composed of many fibers enclosed in protective coverings and strength members. Common features for fiber optic cable include polarization maintaining, graded index, and metalization. Most outdoor fiber cables are loose buffer design, with the strengthen member in the middle of the whole cable, the loose tubes surround the central strength member. Inside the loose tube there is waterproof gel filled, whole cable materials used and gels inside cable between the different components will help make the whole cable resist of water.
 Single-Armored Tight Buffered Water-proof Indoor Outdoor Cable
Typical outdoor fiber optic cable types are used for aerial, direct buried and duct applications.
Loose Tube Cables
Loose Tube cables are the most widely used cables for outside plant trunks, as it can be made with the loose tubes filled with gel or water absorbent powder to prevent harm to the fibers from water. Loose Tube Fiber Optic cables are composed of several fibers together inside a small plastic tube, which are in turn wound around a central strength member and jacketed, providing a small, high fiber count cable. They can be installed in ducts, direct buried and aerial/lashed installations for trunk and fiber to the premise applications. Loose tube cables with singlemode fibers are generally terminated by spicing pigtails onto the fibers and protecting them in a splice closure. Multimode loose tube cables can be terminated directly by installing a breakout kit, also called a furcation or fan-out kit, which sleeves each fiber for protection.
Ribbon Cable
Ribbon cable is preferred where high fiber counts and small diameter cables are needed. This cable has the highest packing density, since all the fibers are laid out in rows in ribbons, typically of 12 fibers, and the ribbons are laid on top of each other. Not only is this the smallest cable for the most number of fibers, it’s usually the lowest cost. Typically 144 fibers in ribbons only has a cross section of about 1/4 inch or 6 mm and the jacket is only 13 mm or 1/2 inch diameter! Some cable designs use a “slotted core” with up to 6 of these 144 fiber ribbon assemblies for 864 fibers in one cable! Since it’s outside plant cable, it’s gel-filled for water blocking or dry water-blocked. These cables are common in LAN backbones and data centers.
Armored cable is used in direct buried outside plant applications where a rugged cable is needed and/or for rodent resistance. Armored cable withstands crush loads well, for example in rocky soil, often necessary for direct burial applications. Cable installed by direct burial in areas where rodents are a problem usually have metal armoring between two jackets to prevent rodent penetration. Another application for armored fiber optic cable is in data centers, where cables are installed under the floor and one worries about the fiber cable being crushed. This means the cable is conductive, so it must be grounded properly.
Aerial Fiber Optic Cable
Aerial cables are for outside installation on poles. They can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. A widely used Aerial Cable is optical power ground wire (OPGW) which is a high voltage distribution cable with fiber in the center. The fiber is not affected by the electrical fields and the utility installing it gets fibers for grid management and communications. This cable is usually installed on the top of high voltage towers but brought to ground level for splicing or termination.
Indoor/Outdoor Cables
Fiber Optic Indoor/Outdoor Cables are designed to meet both the stringent environmental requirements typical of outside plant cable AND the flammability requirements of premise applications. Ideal for applications that span indoor and outdoor environments. By eliminating the need for outside to inside cross-connection, the entire system reliability is improved and with lower overall installation costs.
It is often necessary to install fibers under water, such as crossing a river or lake where a bridge other above water location is not possible. For simple applications a rugged direct burial cable may be adequate. For true undersea applications, cables are extremely rugged, with fibers in the middle of the cable inside stainless steel tubes and the outside coated with many layers of steel strength members and conductors for powering repeaters. Submarine cables are completed on shore, then loaded on ships and laid from the ship, often while operational to ensure proper operation.
fiber-mart.com offers a comprehensive range of multimode fiber cable and single-mode fiber optic cables. Indoor, outdoor, armoured, tight buffered or loose tube structures, which cover all possible applications.