I recently heard that pulling fiber cables by the aramid yarns can damage the fibers. What is the proper method for pulling premises optical fiber cables?
Aramid yarns are the strength elements of the cable and specifically used so optical fibers are not damaged during installation. They also provide the mechanism for safely pulling the cable during installation. Pulling a premises optical fiber cable via its jacket is not recommended and highly likely to cause serious damage to the optical fibers.
If a premises optical fiber cable has multiple jackets and aramid yarn layers, remove approximately 12” of each jacket to expose the aramid yarns and then knot all of the yarns together. Attach the pulling line to the yarns and pull the cable using industry standard pulling techniques.
Does Superior Essex offer optical fiber cables that have multiple types of fiber within one cable?
Yes; our hybrid optical fiber cables are manufactured with any combination of glass types. These custom-made cables require production lead time and minimum order quantities when ordered.
Why doesn’t Superior Essex provide glass specifications on the fiber catalog pages?
Since there are multiple types of singlemode and multimode glass types available, Superior Essex offers a comprehensive chart, called the Optical Fiber Specifications. This chart lists all of the different glass types and all of the performance parameters for each.
What determines if the space above a suspended (drop) ceiling is a plenum?
A plenum ceiling is one that uses the space between the top of the suspended ceiling and the bottom of the floor above to handle air for ventilation. All suspended ceilings are not plenums; some may use HVAC ductwork to move air to returns and diffusers located in the ceiling tiles (a ‘dead’ ceiling). Consult the local code authority to confirm that a suspended ceiling is a plenum. The NEC requires the use of plenum-rated cable (or cable in rigid or intermediate metal conduit) for plenum spaces but permits general purpose-rated cable in non-air handling ceilings and walls.
However, this requirement may be superseded by local codes; for example, conduit may be required even with plenum cable. Know the local code before installing, or even ordering, the cable.
Should cable slack be included in installations?
Yes; slack may be necessary to accommodate future cabling system changes. The recommended amount of slack is 10 feet, regardless of media, for the telecommunications closet. At the outlet, the recommended optical fiber slack is three feet, while one foot is recommended for twisted-pair cables.
May I mix fibers with a core diameter of 62.5 μm and 50 within a system?
While technically feasible, mixing 50 µm and 62.5 μm fibers is not recommended. Industry standards typically require uniform fiber types in each link, including patch cords and jumpers. In addition, linking 50 µm and 62.5 μm fibers typically results in higher coupling losses.
If I request standard 50 micron multimode fiber, why does Superior Essex provide laser optimized 50 micron TeraGain 10G/150 fiber capable of transmitting 10Gb Ethernet out to 150 meters as a standard offering?
Although this fiber is offered by competitors at a premium, Superior Essex offers TeraGain 10G/150 as a standard offering for 50 micron multimode requests. With the higher bandwidth available in the TeraGain 10G/150 fiber, customers have built-in future-proofing at no additional cost.
What are the different types of optical fibers used for communications transmission connections?
There actually many specific types of optical fibers that have been developed over the years. However, there are three main types of optical fiber used today for standard communications applications.
There are two (2) multimode fibers (MMF): used for relatively short links (< 1.6 miles) or low data rate transmission typically < 1 gigabits per second
a. 50/125 micron
b. 62.6/125 micron
The third type is called singlemode fiber (SMF): used for long distance links, usually well over 2 miles and data rates that are typically in excess of 1 gigabit per second
What is the difference between 50/125 and 62.5/125 MMF?
The physical differences between these fibers are fairly small with respect to construction. The core area of the fiber, either 50 microns or 62.5 microns, is where the difference lies. Because of the nature of how laser light or light-emitting-diode (LED) light travels down these fibers, the smaller the core usually means a greater ability of the fiber to care information over a given distance. Or the reverse being, the smaller the core the greater the distance a given amount of information (data rate) can be transported. This is the most critical aspect of how optical fibers are specified and where the most activity is spent developing newer and better multimode fibers.
What is the difference between tight buffer and loose buffer?
First, it is helpful to understand that loose-tube and loose-buffer are one and the same. The same goes for tight buffer and tight tube. The tight versus loose desciption decribes how the basic fiber is packaged within the finished cable. The names actually describe how the fiber is placed within the overall cable. Loose buffer means that the fibers are placed loosely within a larger plastic tube. Usually 6 to 12 fibers are placed within a single tube. These tubes are filled with a gel-like compound that protects the fibers from moisture or physical stresses that may be experienced by the overall cable. These designed are typically specified and used for outside plant (OSP) applications such as directly buried in the ground, lashed or self-supporting aerial installations and other outside-the-building applications. These cables require addition work when the fibers are to be terminated. The addition work involves cleaning the water-blocking compounds from the cable and fibers as well as the use of "break-out" kits when the individual fibers are to be terminated.
For tight buffer designs, each fiber is coated with a plastic, usually with an outside diameter of 900 micron. Cables that are used inside buildings (ISP) will usually use this design. Tight buffer cables can be manufactured with up to 144, 900 micron fibers and have cable ratings of OFNP or OFNR.
When would a fiber optic cable be used in place of a copper cable for communications?
The primary reason that optical fibers are specified for certain communications applications primarily related to the amount of information to be sent and the distances between sending and receiving points on the network. For most applications where high volumes of telephone voice circuits are to be supported SMF is specified. For moderated data transmission data rated and distances MMF is used. For short distance (<300ft) and moderate bandwidth, copper is typically used.
How are fiber optic cables specified?
There are many items to consider when determining which cable design is best suited for a specific application.
In a nutshell, fiber optic cable designs types are specified based on where the cable will be installed, the transmission applications that need to be supported, building code requirement, etc.
The basic questions to consider when defining what cable type include:
- Is the cable to be installed within a building vs. outside, between buildings?
- What are the applications (Ethernet, ATM, etc.) will be supported?
- Will the cable be installed vertically between floors and/or horizontally between rooms on a single floor?
Once you determine the answers to the above questions, you can decide which cable will work best with your application.
What is a hybrid cable?
A hybrid cable contains more than one fiber type in the same cable. For example, a private network application might call for both singlemode and multimode fibers. Placing both fiber types in the same cable would result in installation savings since there would be no need to install two separate cables.
Is there a standard jacket color?
For premise cables, the jacket color is dependent upon the fiber type in the cable. For cables containing singlemode fibers, the jacket color is yellow. For cables containing multimode fibers, the jacket color is orange. For outside plant cables, the standard color is black, however other customer preferences can be accommodated as well.
How is water migration prevented in the cable design?
Traditionally, cable designs have utilized a jelly-flooding compound in the core. By filling the interstitial voids with this compound, the migration of water within the cable has been blocked preventing water ingress along the core. Technological improvements have been made and water migration is now typically prevented by placing dry, water reactive components (Super Absorbent Polymer materials) within the cable core. These SAP components work by forming a gel compound when in contact with water. The gel acts as a barrier by filling the interstices of the core and prevents water penetration. By using cables with a dry core, significant construction savings can be realized because cable access time is reduced by eliminating the step of cleaning the buffer tubes during installation and handling.
What performance standard does Superior Essex use to qualify fiber optic cables?
Superior Essex' OSP fiber optic cables are tested to meet or exceed all of the specifications of Bellcore GR-20-CORE, Generic Requirements for Optical Fiber and Optical Fiber Cable. Superior Essex' OSP cables also test in accordance to the Rural Utilities Service (RUS), formerly REA, standard for fiber optic cable. For fiber optic cables intended for premise applications, Bellcore GR-409-CORE, Generic Requirements for Premises Fiber Optic Cable, was used as the qualification standard.
What is the difference between Single Mode (SM) and Multimode (MM)?
SM (single mode) is a form of optical transmission in which a single mode (path) of light travels down a fiber from one end to the other. Multimode is a form of transmission in which many modes of light travel down a fiber simultaneously.
Are Zip ties suitable for securing fiber optic cables?
We do not recommend the use of Zip ties for securing fiber optic cables. Due to the common tendency toward over-zealous cinching, zip ties may compromise attenuation performance or in extreme cases cause fiber breakage due to the high level of pressure exerted on the fiber.
What is dark fiber?
Dark fiber is a term used to describe optical fiber that is installed, but not in service and not connected to any device. Dark fiber is usually installed to avoid the expense of having to go back and lay fiber again later.
How will the new standards for 40 Gb and 100 Gb Ethernet affect my installed base of optical fiber?
Although the IEEE 802.3ba standards for 40 Gb and 100 Gb Ethernet are still being formulated, several optical fiber types have already been targeted for use in these standards.
Not surprisingly, single mode fiber is being considered for lengths up to 40 fkm using 10 parallel single mode fiber channels running at 10 Gb/s each. For multimode fiber, the only types in consideration are laser-optimized 50 micron OM3 or the soon-to-be-standardized OM4 fiber with minimum 850 nm Effective Modal Bandwidths of 2000 and 4700 MHz-km, respectively.
Currently, both fibers are used for 10 GbE serial applications for up to 300 and 550 meters, respectively. Unfortunately, no consideration is being given to 62.5 micron multimode fiber at any wavelength and for any length. If you have 62.5 micron fiber installed in your data center, Superior Essex TeraGain 50 micron 10G/300 or 10G/550 should be considered for any upgrade or new installation.
My upcoming project mandates that I use RoHS compliant cables. Are cables manufactured by Superior Essex RoHS compliant; do you have supporting documentation; and where can I find it?
Yes, Superior Essex manufactures RoHS (Restriction of Hazardous Substances) compliant products. These cables can be easily identified by the appearance of a RoHS logo located near the standards compliance box of our print and online product specification sheets. (Keep in mind that the most current information is available online.)
The Restriction on Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives are aimed at reducing the hazardous materials content in electronic products as well as increasing the recycling efforts for these products and became effective July 1, 2006. RoHS specifically bans or restricts the use of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated biphenyl ethers (PBDE).
General information on RoHS compliance is available on our Web at RoHS Compliance as well as on the RoHS website.
To obtain a stand-alone documents for a specific part number(s), contact your inside sales manager. He or she can provide the documentation.
If you have other questions concerning RoHS compliant cables manufactured by Superior Essex, please call Technical Support at 877.263.2818 or via email.
I need an interlock armored optical fiber cable for a plenum application. Can I use a riser rated cable on the inside as long as the outer jacket is plenum rated?
No. In a plenum space, not only does the entire interlock armored cable need to be plenum rated, but the inner component cable(s) must also be plenum rated. The NFPA does not allow the entire cable to be plenum rated – even if it passes the test at a nationally recognized test laboratory (NRTL) – if it has a riser cable on the inside. Further, the cable can't be considered plenum rated because if the interlock armor is ever removed in a plenum space, the remaining component riser cable would be in violation of the NEC code.
If you have other questions concerning cable ratings, please call Technical Support at 877.263.2818 or via email.