Choosing the Right Fiber Optic Cable

There are so many fiber optic cable options available that one might wonder where to start. This article will set you on the right path in the decision process. Let’s begin by focusing on the broad categories of fiber optic cable. Below you can make “either/or” decisions. A handy reference chart that summarizes key cable features can be found below.

 

 

Multimode or Single Mode?

 

Multimode Cable - Applications: Multimode fiber is used to transport high volumes of data over relatively short distances (compared to single mode fiber). Common applications include Data Centers and other Local Area Network (LAN) applications. Note that multimode distance capabilities have increased over the years. Multimode fiber cable now offers an economical alternative to single mode cable for certain applications. Design: Multimode cable has a relatively large core (either 50 or 62.5µm) that enables multiple streams of data to be transported simultaneously.

 

Single Mode Cable - Applications: Telcos and CATV companies use single mode cable to transport signals over long distances. Business campuses and other institutions also use single mode cable for longer cable runs, such as links between buildings. Design: The core diameter of single mode fiber is so small (9µm) that it permits only one mode of light to pass through it at any given time. This characteristic reduces attenuation and enables light to be transmitted over great distances. While the purchase price of single mode cable is less than multimode cable in general, single mode transceivers and network interfaces are generally more expensive than those used for multimode systems.

 

 

Simplex or Duplex?

 

Applications: Simplex and Duplex cables are typically used for fiber optic patch cables and desktop installations that don’t require a high fiber count. Design: Simplex cables contain a single 900µm coated fiber or a combination of a 900µm coated fiber surrounded by an aramid yarn strength member with an outer jacket diameter varying between 3, 2, 1.8 and 1.6mm. Duplex cables contain two 900µm coated fibers surrounded by an aramid yarn strength member with an outer jacket diameter varying from 3, 2, 1.6 and 1.2mm.

 

Loose Tube or Tight Buffer?

 

Loose Tube Cable: Applications: Loose tube cable is ideal for use in long distance outside plant applications that require a high fiber count. The cable is designed to withstand harsh outdoor environments; the cable’s unjacketed fibers are free to expand and contract with temperature changes. Design: Fibers within loose tube cables are surrounded by a water blocking component (either gel or a dry water-blocking material). Although loose tube cables are engineered to withstand damp outdoor environments, they are not designed to be submerged in water, but can come in contact with water. Terminating Loose Tube Fibers – The fibers within the gel-filled tubes of the cable have a very thin acrylate coating which is 250µm in diameter. Before terminating, the fibers must be put into small plastic tubes (called a breakout kit or box). The tubes protect the thin fibers and make them easier to handle when terminating and connecting to network equipment.

 

Tight Buffer Cable: Applications: Tight buffer cable is typically used indoors. A tight buffer (cable jacket) encapsulates each fiber. The 900 micron buffer enables the fibers to be directly terminated without requiring a breakout kit, which saves substantial time. These cables do not typically provide protection from water migration and do not isolate fibers well from the expansion and contraction of other materials due to temperature extremes. Tight-buffered cables, often called premise or distribution cables, are ideally suited for indoor-cable runs. Design: Tight buffer cables have two protective coatings; a 900 micron PVC jacket and 250 micron acrylate coating, all encased in an outer PVC jacket.

 

 

 

Distribution or Breakout?

 

 

Distribution Cable: Applications: Distribution cable is ideal for networks that terminate multiple fibers at a common location, such as a patch panel or communications closet. Fibers within a distribution cable have their own 900 micron individual cable jackets. This space-saving feature enables up to 144 fibers to be bundled within the cable. Fibers in a “Micro Distribution” cable do not have the 900 micron tight buffered PVC jacket, instead they contain color coded 250 micron acrylate coated fibers. Because of the decreased diameter of the individual fibers in the cable, a micro distribution cable may contain up to 432 or more fibers. A disadvantage of micro distribution cable is that the unjacketed fibers require the use of a breakout kit for termination. Design - Distribution cable contains a number of 250µm - 900µm fibers that are color-coded for easy identification. The cable includes an aramid yarn strength member and a thick outer jacket that provides protection and strength during cable installation. If required, the cables can be purchased with interlocking armor.

 

Breakout Cable: Applications: Breakout cable is ideal for applications where fibers are connected directly to equipment, including local hubs. Also, the robust design of breakout cable makes it well suited for use as drop cables. Design - Breakout cable differs from distribution cable in that each of the fibers in a breakout cable is 900 micron tight buffered and surrounded by aramid yarn all encased in a 2mm or 3mm PVC jacket. Then all of these 2 or 3mm jacketed fibers are encased in an outer jacket. This additional jacketing can save substantial time and installation cost, especially if the fibers are being terminated with connectors. One disadvantage of breakout cable is that the fiber jackets take up room within the cable, so breakout cable cannot contain as many fibers as distribution cable. Fiber counts for breakout cable are typically 2-24 fibers (maximum is 48 fibers).

Different Types of Cable Jacketing

In the fiber industry, we have all probably seen the words plenum or riser in our day, as these are two of the most common jacket types in the United States. In Europe we are seeing more Low Smoke Zero Halogen cables being utilized. But there are other options out there in the fiber optic world that are lesser known and talked about, they are the likes of Low Smoke Zero Halogen (LSZH), and Polyethylene (PE).

 

When looking at the construction of any fiber optic cable, you will notice that the jacket is the first line of defense against physical damage from chemicals, water, burning and other potentially damaging effects that would compromise the viability of the cable. Cable jackets come in multiple colors, but there are industry standard color codes such as aqua for OM3 or yellow for single mode, but in some cases there are custom colored jackets. You will also see foot markers on the outer jacket, showing you length of the cable, and even a print string showing the type of fiber, brand of cable, and type of cable construction. The print string will also contain information as to whether or not the cable is UL listed, and if it is, it will contain the UL number. Most cable jacket material is made from PVC or Polyvinyl Chloride, and there are additives that determine its jacket rating.

 

Plenum and riser ratings are defined by the National Electrical Code (NEC). They are also responsible for the standards that these cables must abide by in order to be classified as plenum or riser cabling. This standard basically states that if a fire were to start within a structure, how much would these compounds contribute to the fire, and create a “fuel” source - transporting the fire from place to place along the cable.

 

Most fiber optic cables that adhere to these fire standards are Underwriter Laboratories (UL) tested, meaning that they bear the UL marker on the cable jacket and have been certified to meet the NEC Standard for the cable jacket type. These UL Listings are independently tested, and qualified to ensure that the safety measures are upheld. They (UL) have no monetary stake in the items that they test, and consumers can be assured that this UL listing means that the safety standards are upheld. These listings are given and can be taken away at any point if the quality of the product does not continue to meet that UL standard.

 

The real question that most technicians ask in the field is where to use what type of jacket. Below we will go into a breakdown of the cable jacket types and where they can be utilized within a building or structure.

 

Plenum Cable

 

Plenum has the highest fire rating, meaning that it can be installed in all of the plenum spaces within a building such as the air ducts and ventilation systems - any part of the building that has to do with heating or cooling. Plenum can sometimes be utilized in any space within a building as an alternative to other jacket types. Plenum cables are less hazardous and create less smoke and toxic fumes in the case of fire. If a job requires plenum cable then plenum cable must be installed, there are no alternatives for this type of cable install. Plenum cables for the above reasons are usually slightly more expensive than the other cable jackets.

 

Riser Cable

 

Riser cabling is only to be used within riser spaces in a building - such as between building shafts, for vertical runs. It is meant to be a backbone cable, the fire ratings that fit a riser rating are not as strict as plenum. You can utilize a plenum cable within a riser space, but you cannot utilize a riser cable in a plenum space. Such as in the case of a ventilation shaft - you could not install a riser cable because this is a plenum air space, but you can install riser say in an elevator shaft between the floors of a building. Typically, riser cables are less expensive than plenum because the standards are less stringent.

 

Low Smoke Zero Halogen (LSZH) Cable

 

Low Smoke Zero Halogen cable jacketing or LSZH is a separate classification from riser or plenum cables because it does not contain the same compounds or thermoplastics that produce smoke and other hazardous chemicals that could be harmful to humans and animals that may be in the vicinity of the cable, if it ever should burn. To be considered low smoke zero halogen cable, it must be made of flame retardant materials that do not excrete halogens, and produces little to no smoke when it burns. LSZH is not the same as a plenum cable - they are two different fire ratings. While it may seem beneficial to use LSZH within every space in a building, this type of cable does not fit the bill for every single application. Since this product is far more expensive than other compounds, it does not make sense to install this in areas that do not require a less hazardous, or low smoke material. LSZH is highly recommended for areas that have poor ventilation, where people tend to congregate or in a confined space. LSZH is primarily utilized in Europe currently but, this type of cable is gaining traction within the US markets. .

 

PE Cable

 

PE (polyethylene) rated cable is primarily used for outdoor cables only; this is not a cable that can be installed more than fifty feet inside of a building. PE cable jacket's superior weather, temperature and water or moisture resistance makes this a great pick for harsh weather conditions and installations, but its rigid characteristics make it difficult to utilize in environments that require flexibility or movement of the cable. It also boasts superior UV protection because its black color absorbs the sunlight, which is a typical characteristic for outdoor rated cabling.

 

While there are more cable ratings and classifications than these shown above, these are the most common types that your average technician will run into on the job more. Familiarity with the cable jacket types is never a bad thing to have in a technician’s pocket. Knowing and being able to define what makes a plenum cable plenum or riser cable riser is superior knowledge that will benefit the technician on future jobs. .

Introduction of Armored fiber cable

by www.fiber-mart.com

Armored Fiber Cable Structure

As shown in the below picture, the optical fibers of the armored fiber cable are in the center of the cable covered by metal armor. The metal armor is covered by Kevlar firstly, then by the outer jacket. This is usually the most basic structure of armored fiber cables. For different applications, the structure will change accordingly. Kindly visit “Armored Fiber Cable Structures” for more details about different structure of the armored fiber cable.

 

 

Types of Armored Fiber Cable

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 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. Both types of these armored fiber cables enable installation in the most hazardous areas, including environments with excessive dust, oil, gas, moisture, or even damage-causing rodents.

 

 

Armored Fiber Cable for Indoor and Outdoor Use

Armored fiber cable can be used for indoor, indoor/outdoor and outside plant (OSP) applications. According to different installation environments, tight-buffered armored cable and loose-buffered armored cable are generally adopted: loose-buffer armored fiber cables are usually applied in outdoor applications, while both loose-buffered and tight-buffered armored fiber cable can fit indoor and indoor/outdoor applications.

 

Indoor Armored Fiber Cable

Armored cable used for indoor applications often consists of tight-buffered or loose-buffered optical fibers, strengths members and an inner jacket. The inner jacket is commonly surrounded by a spirally wrapped interlocking metal tap armor. As the fiber optic communication technology develops rapidly with FTTX, there is a fast growing demand for installing indoor fiber optic cables between and inside buildings. Indoor armored fiber cable experiences less temperature and mechanical stress and it can retard fire effectively.

 

Indoor/Outdoor Armored Fiber Cable

This armored fiber optic cable shares much popularity in today’s telecommunication network, which allows links from building to building eliminating the transition from indoor cable to outside plant cable. The following picture shows the structure of commonly used multi-fiber I/O armored fiber cable.

 

Outdoor Armored Fiber Cable

Armored cable for outdoor is made to ensure operation safety in complicated outdoor environment, and most of them are loose buffer design: with the strengthen member in the middle of the whole cable, loose tubes surround the central strength member. Inside the loose tube there is waterproof gel filled to make the cable water resistance. The combination of the outer jacket and the armor protects the fibers from gnawing animals and damages that occur during direct burial installations.

 

 

How to Select Armored Fiber Cable?

The selecting of armored fiber cable is like the selection of standard fiber cables. Fiber type (OS2, OM1, OM2, OM3, or OM4), fiber count and cable riser should all be considered. However, there is many special properties of armored fiber cable, the armored fiber cable selection should also consider many other factors.

 

Armor Type of Armored Fiber Cables

The market can provide armored fiber cables with different types of armor tubes which are with different structures and materials. The most commonly used armor tubes are with interlock design and corrugated design as shown in the above picture. For now, the interlock armored fiber cable is very popular and being used in a lot of indoor and indoor/outdoor applications. Corrugated armored fiber cable is often used in outdoor applications. As for the materiel for armor tube, steel and aluminum are the most commonly used. Now light steel armored fiber cables are being widely used in a lot of indoor applications, because of its lower weight and flexible properties.

 

 

Pre-Terminated or Field-Terminated Armored Fiber Cables

As there is a strong metal armored tube inside the armored fiber cable, the termination of armored fiber cable is difficult than that of standard fiber optic cables. In some applications, field-terminated armored fiber cable is better in outdoor applications. While, to save time and ensure transmission quality, many installers will choose pre-terminated armored fiber cables for indoor applications. The pre-terminated armored fiber cables provided by the market are mainly armored fiber patch cable and armored fiber trunk cable. The former looks like the standard fiber patch cable, but it is stronger than the traditional fiber patch cable and is more flexible during cable for it can provide larger bend radius. Pre-terminated armored fiber trunk cable is a length of armored fiber cable with several legs on each ends terminated with fiber optic connectors. Kindly visit “Armored Fiber Cable” page for more specific details about pre-terminated armored fiber cables.

 

Conclusion

Armored fiber cable presents a premium solution to secure your network by protecting fiber links, which is specified as the primary backbone due to its distinct advantages for space efficiency, lower cost of materials and installation, as well as less risk of downtime and damage.Fiber-Mart offers a great variety of armored cable.  and tested rigorously to ensure product reliability and durability, and all the fiber cables are ready in stock for delivery in volume.welcome to contact with us: product@fiber-mart.com.