The electrical utility sector is increasingly dependent on high speed optical networks to aid daily operations. For more than two decades, utilities have used fiber optic media to support their own personal internal applications. In additional recent years, public power companies plus an occasional electric cooperative have ventured into SZ stranding line for the advantages of their customers and the generation of additional revenue streams. Later on, new construction and smart grid initiatives promise to expand fiber’s role even farther into electric utility operations. The very last point is a reasonably statement considering fiber is definitely available on transmission lines and distribution lines, in generating stations, and even in substations.
So, when it is a given that optical fiber is a reality in the electric utility industry, then its necessary for those with responsibility for your control over utility assets to learn several of the basic groups of optical cable products and where those products best easily fit in the electric grid. Since many of the fiber employed by utilities is deployed in the outside-plant, probably the most common questions center around picking ribbon versus conventional loose tube cable designs and where one solution is much more economically viable compared to the other.
Outside plant cables, either aerial or underground, get even closer the property.
Both ribbon cables and conventional loose tube cables are staples in the telecommunications industry and have been around for years. Both products perform well in harsh outdoor environments, and both can be bought in a multitude of configurations, including: all-dielectric, armored, aerial self-supporting, etc. The primary distinction between these two product families will be the manner where the individual fibers themselves are packaged and managed inside the cable. A ribbon cable has the individual fibers precisely bonded together in a matrix which may encompass as few as four or up to 24 fibers. Typically, however, these matrixes, or “ribbons” are bonded together in a small group of 12 and placed in a tube that holds multiple ribbons. In comparison, a loose tube cable design has between 2 to 24 individual fibers housed in multiple buffer tubes with each fiber detached from the other.
Practically anyone within the electric utility industry with any amount of being exposed to optical fiber products will be informed about the fundamental structure of loose tube cable. Ribbon cables, on the flip side, have enjoyed widespread adoption among regional and long-haul telephony providers but might still be unfamiliar for some inside the electric utility space. This unfamiliarity posesses a price since ribbon products can provide a four-fold advantage over loose tube designs in many applications:
Ribbon cable could be prepped and spliced much more rapidly than loose tube cables. This advantage results in less installation time, less installation labor cost, and significantly less emergency restoration time.
Ribbon cables enable a lesser footprint in splice closures and telecommunications room fiber management.
Ribbon cables offer greater packing density in higher fiber counts which enables more effective consumption of limited duct space.
Ribbon cables are typically very cost competitive in counts above 96 fibers.
The very first two advantages in the list above are byproducts in the mass fusion splicing technology enabled by ribbon cable. A mass fusion splicer can splice every one of the fibers inside a ribbon matrix simultaneously. Thus, if a 12 fiber ribbon is used, all of the fibers could be spliced within 12 seconds with average splice losses of .05 dB. In contrast, the conventional loose tube cable requires each fiber being spliced individually. So, by way of comparison, FTTH cable production line requires 12 splices to be fully spliced while a 144 fiber count loose tube cable demands a full 144 splices. In addition to the time savings, a decreased total amount of splices also yields a reduction in the amount of space needed for splicing. Hence, it comes with an associated decrease in the volume of space found it necessary to support splicing in closures and in telecommunications room fiber management.
Your reader with experience using ribbon cable might offer two objections at this stage. The very first objection is definitely the value of mass fusion splicing equipment, and also the second objection is the painful and messy procedure of prepping large fiber count unitube ribbon cables. The very first objection is easily overcome by simply studying the current prices of mass fusion splicers. Over the past few years, the fee difference between single-fiber and ribbon-fiber splicing equipment has decreased dramatically. The second objection has become overcome through the development of all-dry optical cable products. Older ribbon cable products were painful to prep as a result of infamous “icky-pick” gel utilized to provide water-blocking. The unitube form of many ribbon cable products translated into too much gel as well as a general mess for that splicing technician. However, technologies allow both conventional loose tube and ribbon products to meet stringent water-blocking standards without having gels whatsoever. This dramatically decreases the cable prep time when splicing for both product families. However, the standard style of ribbon cables implies that the advantages of all-dry technology yield even more substantial reductions in cable prep time.
Even for low fiber count applications, ribbon cables possess a significant advantage in splicing costs. The ideal point for conversion to ribbon cables typically occurs at 96 to 144 fibers according to the labor rates utilized for economic modeling. In that variety of fiber counts, any incremental cost difference between ribbon and loose fiber configurations will be offset by savings in splicing costs and installation time. For fiber counts equivalent to and in excess of 144, the carrier will need a compelling reason never to deploy ribbon cables because of the reduced value of splicing and incredibly comparable material costs.
Splicing costs vary tremendously in accordance with the local labor market. Typically, however, single-fiber fusion splicing expenses are anywhere between $23 and $35 per-splice on the national level for standard outside-plant cable. For cost comparison purposes, we will split the difference and believe that we need to pay $28 per-splice whenever we sub-contract or outsource single-fiber splicing. Whenever we outsource ribbon-fiber splicing, we shall imagine that each 12 fiber ribbon splice costs us $120. Ribbon-splicing costs also vary tremendously depending on the local labor market, although the $120 number is probably inside the high-average range.
So, in relation to those assumed splice costs, an ordinary loose-tube cable splice will definitely cost us $4,032.00 in the 144 fiber count (144 single fibers x $28 per-splice) whereas the comparable ribbon cable splicing costs will be $1,440.00 (twelve 12-fiber ribbons x $120 per-splice). This provides us an overall total savings of $2,592.00 in splicing costs at each splice location. If the 144 fiber ribbon cable costs the same or below the comparable loose-tube cable, then the case for ribbon at that fiber count and better will be the proverbial “no-brainer.” Every time a ribbon cable is available that will do the job within this scenario, there is little reason to take into consideration the alternative.
The case for ribbon versus loose-tube optical cable is less compelling at lower fiber counts. As an example, when using those same per-splice costs in the 96 fiber count scenario, the ribbon cable saves us $1,728.00 each and every splice location. However, the financial benefit afforded from the splicing can be offset by higher cable price. Additionally, dexkpky80 variety of splice locations may vary greatly from a application to another. Within a typical utility application, however, 96 fiber configurations represent the point where cable costs and splicing costs have a tendency to break regardless if comparing ribbon to loose tube.
The economics of fiber counts notwithstanding, you may still find a number of locations where either ribbon or loose-tube is definitely the preferred option. By way of example, it will require four splices to mend a 48 fiber count ribbon cable in comparison to 48 splices for that loose-tube equivalent. On certain critical circuits, therefore, it could be desirable to possess optical fiber ribbon machine just as a result of advantages in emergency restoration. Also, ribbon cable goods are generally smaller which creates some space-saving advantages in conduit. On the flip side, some applications (fiber-to-the-home, as an example) require multiple cable access locations where we pull out only two to eight fibers from a cable for splicing using mid-sheath access techniques. In those instances, ribbon could be viable with new “splittable” ribbon technologies, but may be less practical for several carriers than conventional loose tube. However, the gel-free technology located in both ribbon and loose-tube is a large labor savings feature in those circumstances. Aerial self-supporting cables (ADSS) still require the application of some gels, but any utility company installing fiber optic cable in almost any other application needs to be leaving the gel-remover in the shop. “Icky-pick” in conventional ribbon and loose-tube cables can be a relic of the 90’s along with an accessory for labor hours that may be easily avoided.
To sum it up, there is certainly not much of a single network design that suits all applications, rather than one particular cable that suits all network designs. However, learning the options and knowing where they fit can significantly impact installation time, labor costs, and emergency restoration time. All of the alternatives are field-proven and have been popular for several years. Utilities can leverage the main advantages of these different solutions by simply remembering what is available, and applying just a little basic math to compare cable costs, splicing costs, and labor hours.