Fiber Optic Cable Specification

Many structured cabling installations begin with the preparation of a detailed written specification for each system component. Such specifications may be necessary to ensure the correct product is used for the intended application. Specifications also ensure all products offered are equal in a competitive-bidding situation. Consultants and end users often find that they lack the breadth of knowledge or experience necessary to prepare a complete, detailed specification for optical fiber and fiber optic cable. This fact is not surprising because it takes a significant effort to keep abreast of changing product offerings as well as the most recent product evaluation and measurement technology. However, consultants and end users can use industry standards to specify the necessary products without having to delve into excruciating detail.

Specifications for optical fiber and cable can be, and often are, long and arduous; they address a myriad of technical considerations. These considerations include mechanical, environmental, and dimensional characteristics, not to mention the finished product’s compatibility with building codes and transmission equipment. Consultants and end users frequently prepare lengthy specifications, attempting to cover all pertinent details. This effort requires a thorough knowledge of cable design, optical science, and the details of scores of measurement methods. Panels of industry experts have developed national and international standards for fiber and cable; these standards can be the basis for the desired brief, accurate, detailed specifications.

Cables intended for direct burial underground should, in most cases, incorporate a steel tape armor for protection against gnawing rodents. Metallic armor has proven to be an effective rodent 
protection in controlled tests.

For aerial installations, outdoor fiber optic cable require a messenger wire for lashing. However, some cables have an integrated messenger wire in a figure-eight cross section. Also available today are some all dielectric self-supporting aerial cables, which contain no metallic elements but have sufficient tensile strength to support their own weight and a reasonable ice and wind load.

The most popular loose tube cable includes buffer tubes, each of which contains one to 12 color-coded fibers. Some other cables include ribbons of fiber, rather than loose fibers in buffer tubes. Up to 24 fibers, joined together side-by-side, form a fiber ribbon. Stacks of these ribbons are in buffer tubes, creating a cable with a large number of fibers in a small cross-sectional area. Ribbon cables are popular in telephony and other long-haul applications and useful in crowded ducts where dense packing offers an advantage. Mass-fusion-splicing technology allows installers to splice 12 fibers in a ribbon simultaneously, offering labor savings in high-fiber-count applications. Ribbon cables are not common in premises applications but may become more popular as fiber becomes more prevalent in premises networks.

Indoor/Outdoor

Indoor outdoor cable incorporate the characteristics necessary for both applications; they are waterblocked for moisture protection and are sunlight-resistant. Indoor/outdoor cables also meet one or more of the code requirements for flame-spread resistance and smoke generation.

They can be useful in eliminating a splice point for a building-to-building run in a campus environment. They resemble outdoor cables more closely than indoor cables in design and appearance 
and usually require a fanout kit for field termination.

Fiber optic cable specification

A detailed cable specification considers all environmental and regulatory factors that concern the installation environment, including temperature, mechanical loading, moisture, sunlight, 
flammability, rodents, and chemicals. Fully specifying each cable also requires a test or measurement method and criteria. Once again, standards are available to simplify this task.

Two sister documents published by the Insulated Cable Engineers Association (ICEA-South Yarmouth, MA) are useful as detailed product specifications. The ANSI/ICEA S-87-640 Standard for Outside Plant Communications Cable and the ANSI/ICEA S-83-596 Standard for Fiber Optic Premises Distribution Cable cover outside- and inside-plant cables, respectively. A third document, which will be designated S-83-696 and is currently in the works, will address indoor/outdoor cables. In addition to detailed references for test method, loading, and failure criteria for finished cable, these documents also include similar details for the optical fiber. ANSI/ICEA S-83-596 includes a summary of the flammability listing requirements from the NEC. Referencing these documents as appropriate for indoor or outdoor cable ensures you have included a full battery of environmental and mechanical testing and failure criteria in your specification.

In the United States, the federal government is another source for a detailed product specification. The Department of Agriculture’s Rural Utilities Service (RUS) has published a document entitled Specification for Filled Fiber Optic Cables, which provides detailed product specifications for singlemode and multimode fiber, as well as OSP loose-tube cable. The RUS specification even outlines requirements for production and type testing as well as data reporting and manufacturers’ recordkeeping. The RUS conducts technical reviews of cable manufacturers’ products and programs and includes compliant companies’ products on an “accepted list.” By specifying that an OSP cable must be RUS-listed, an end user can take advantage of the RUS’s efforts.

What is Indoor Outdoor Cable

Fiber optic cable that is capable of surviving the outdoor environment and meets the flammability requirements for use inside buildings offers many advantages to the end-user, as well as the installer and distributor. The use of only one type of cable between and within buildings can save many labor hours and reduce material costs by eliminating the need to splice outdoor cables to flame-retardant indoor cables.

Indoor outdoor cable assemblies are designed for general outdoor applications, yet they are riser rated and can be used indoors without the restrictions imposed upon loose tube cables, or non-UL approved cable. Indoor outdoor cable, is like many other terms in the wire and cable industry in that the definition depends on the specifics of the subject in question. In general, “indoor” implies that the cable has at minimum an NEC Fire Resistance Rating so that the cable is not subject to the typical 50-foot indoor length limitation that applies to outside plant (OSP) cables. “Outdoor” generally implies that the construction of the cable is such that it will withstand certain environmental extremes typically only experienced outdoors. Beyond that, the specifics of the design must be examined to determine the suitability of any cable for an application requiring indoor outdoor performance.

Indoor -outdoor Fiber Optic 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, Indoor/outdoor cable can eliminate the need for building entryway splice points, saving both time and money.

Indoor/Outdoor cables combine the flame resistance and safety features of an indoor riser or plenum cable with the durability that is critical for OSP use. The result is a unique, dual-purpose cable that can save time and money by allowing OSP applications to flow seamlessly indoors, using a single cable and no splices.

When referencing unshielded twisted pair (UTP) cables, indoor/outdoor is a special designation of cable intended for limited indoor/outdoor use. This cable was designed for the purpose of connecting the Network Interface Device (NID) located on the outside of a building or residence to the inside services, which may be a small telecommunications closet or simply a wall outlet. This cable typically has a minimum NEC Fire Resistance Rating of CMX plus an additional UL rating of “Outdoor”. Other fire resistance ratings are available as applications warrant. The materials used in Indoor/Outdoor UTP cables provide better low temperature properties and UV protection than their strictly indoor counterparts.

Indoor/outdoor UTP cable is not intended for typical outdoor applications for which OSP cables are designed. As with most UTP cables, Indoor/Outdoor cables lack a grounding mechanism for handling the electrical surge that can occur from a lightning strike or contact with another power source. This is a safety issue and should not be taken lightly! The NEC and NESC both require that electrically exposed cable be enclosed in a metallic covering that is grounded at each end. They further require that any communication cable entering a building must have
the individual conductors terminated in a UL Listed Primary grounding device called a building entrance protector (BEP). This is a safety valve for those occasional instances where the
power surge actually makes its way past the shield or conduit and travels along the conductors. Secondary devices of the type used to protect electronic equipment inside a building are not suitable for BEP use and are not allowed by code.

FiberStore is one of the leading suppliers of fiber optic cable in the China stocking hundreds of thousands of feet of fiber optic cable that are ready to ship same day including all types of single mode fiber optic cable, multimode fiber optic cable, loose tube fiber optic cable, breakout fiber cable, mpo cable, hybrid cable and more.

Fiber Optic Cable Construction

In any detailed discussion of how to deal with fiber optic cable, some fibers are discussed briefly and cable design is required. Eliminating confusion of different terms, and to provide an 
understanding of cable construction will make handling the products less complicated.

Fiber

The cable cross section is two fiber cables for interconnect applications. The construction of the glass can be looked at separately from the design of the cable, as the fiber itself is constructed using distinct materials and is shipped by the fiber manufacturer as a finished product. FiberStore takes the coated optical fiber and incorporates it into a multitude of finished cable products.

All of the glass fiber used by FiberStore is manufactured using the same basic construction. Two layers of glass are covered by a protective coating, the fiber’s core and cladding are both made of silica glass. It is these two layers that propagate the light signal and determine the performance of the fiber. A slight difference in optical characteristics between these layers keeps the signal within the core region. The glass is protected by a dual layer of ultra-violet-cured acrylate material.The coating protects the surface of the glass from abrasion during normal routine handling, there by ensuring the glass maintains it’s high tensile strength. The acrylate coating, which also functions optically by stripping out any light which might enter the cladding region, isremoved for termination and splicing.

Buffer Types

All of FiberStore fiber optic cables fall into one of two categories: tight buffered or loose tube buffered. The two cable buffer styles exhibit different optical, mechanical, and costcharacteristics. Originally, loose tube cable constructions were developed for long haul telephony applications which required a rugged, low cost, high fiber count outside plant cable solution. In a premises wiring plan this cable type is often used between buildings, although recent developments in cable design have produced loose tube cable for indoor/outdoor applications (know indoor outdoor cable). The tight buffer cable construction was developed for both indoor and outdoor premises wiring applications. Most of FiberStore’s tight buffer cables are rugged enough for many inter building applications while offering the tight buffer design advantages of ease of terminations, meeting NEC flammability codes, and cable flexibility.

Tight Buffered Fiber

A thermoplastic material is extruded directly over the acrylate coating, increasing the outside diameter of the fiber to 900 micros (0.9 mm), an industry standard. The tight buffer supplies the fiber with added mechanical and environmental protection, increased size for easy handling, and a simple means of adding color coding for fiber identification. During connectorization, the buffer is stripped back to an exact length as required by the connector manufacturer.

Loose Buffered Fiber

In loose tube cable, the coated fiber “floats” within a rugged, abrasion resistant, oversized tube which is filled with optical gel. Since the tube does not have direct contact with the fiber, any cable material expansion or contraction will not cause stress on the fiber. Much of the external stress placed on the tube also will not be transferred to the fiber. The non-hygroscopic gel prevents water from entering the tube.

Strength Members

FiberStore optical fiber cable designs utilize aramid yarn as the primary strength member. Some designs also use a fiberglass central strength member. Both of these materials serve as the load bearing members of an optical fiber cable during installation. In many cables the aramid also acts as a strength member during termination.

Core Wrap and Ripcords

Core wraps and ripcords are designed to make removal of the exterior cable sheath easier, preventing unnecessary stress to the core. The non-hygroscopic core wrap creates a barrier between the core and the jacket, preventing adhesion and facilitating jacket removal. Ripcords provide a means of stripping back the jacket without the use of invasive tools which could harm the cable core and damage fibers.

Outer Jacket

The true cable jacket is usually the outermost element in the cable design. It serves to protect the cable against environmental hazards and gives the installer a mean of managing the cable. Without the outer jacket, in many designs the buffered fibers would have only the aramid wrap to cover them. Typical jacket materials include Polyvinylchloride (PVC), Polyethylene (PE) or Polyvinylidene Fluoride (PVDF). Also, without selectively choosing the appropriate jacket material most cables would be entirely incapable of passing a flame test. Outer jackets are always stripped back to expose the fibers at the point of termination or connectorization.

If you would like to buy our optical fiber cables or want to know more about outdoor cables,hybrid cable please visit our website.

Introduce of Indoor Outdoor Fiber Optic Cables

Indoor/Outdoor Fiber Cable delivers outstanding audio, video, telephony and data signal performance for educational, corporate and government campus applications. With a low bending radius and lightweight feature, this cable is suitable for both indoor and outdoor installations.

Indoor outdoor cable Features:

. Good mechanical and temperature performance
. High strength loose tube that is hydrolysis resistant
. Special tube filling compound ensure a critical protection of fiber
. Filler protect tube optical fiber,with excellent waterproofing performance
. Small cable size, lightweight
. Meet market and user demand

Indoor outdoor cable Applications:

. Indoor&outdoor aerial,pipeline
. Structured (data) wiring systems
. Networks for telecom, cable TV and/or broadcast
. Suitable for direct burial

Indoor fiber cables requires less temperature and mechanical strength than outdoor cables. However they have fire safety concerns; such as fire retardant and emits a very low level of smoke if on fire. It also allows smaller bend radius for installation.

Indoor fiber cables are usually based on tight buffer design so that they can be mounted both horizontally and vertically. The fibre count is usually 4, 6, 8, 12, 24, 32 etc.

Outdoor fiber cables have more applications than indoor fiber cables. They can be used from laying on ocean beds to connecting various cities or any two buildings on a campus.

Outdoor cables have high mechanical strength and can endure high temperature variations. They design of outdoor fiber optic cable is usually loose tube type so that the drawing force are applied on the cable sheath (cable jacket) and strength members without damaging the inside fibers. The loose tube structure also makes the fiber pulling inside ducts, trench, pipes easy.

Indoor/outdoor optic cables are usually used in Local Area Network (LAN) application so the same cable can be used both outdoor (the link between buildings) and indoor (inside the building). They have the same fire rating as standard indoor optic cables.

Typical indoor/outdoor cables are loose tube and tight buffer designs, and we also supply ribbon cables, drop cables, distribution cables and breakout cables. These are available in a variety of configurations and jacket types to cover riser and plenum requirements for indoor cables and the ability to be run in duct, direct buried, or aerial/lashed in the outside plant. Any fiber counts and cable length can be available from FiberStore, and our Indoor/Outdoor Fiber Cables design can simplify your project.

FiberStore designs, manufactures, and sells a broad portfolio of optical communication products, including passive optical network, or PON, subsystems, optical transceivers used in the enterprise, access, and metropolitan segments of the market, as well as other optical components, modules, and subsystems. In particular, FiberStore products include optical subsystems used in fiber-to-the-premise, or FTTP, deployments which many telecommunication service providers are using to deliver video, voice, and data services. Learn more fiber optic cable specification, fiber optic cable cost and loose tube fiber optic cable on FiberStore web site.