Smart design.Superior value.The better choice.

Sensor Technologyn Fiber optic distributed temperature sensing (DTS) systems and solutionsn Fiber optic cables for petroleum exploration n Fiber optic cables for monitoring safety and structural integrity of tunnels and elevator shafts

Industrial and Specialty Cablesn Polyurethane jacketed copper cables for control and other industrial applicationn Flame retardant, non-corrosive (FRNC) cablesn Low-EMF cablesn Customized copper cable assemblies and solutionsn Hybrid copper and fiber optic cables for specialized applications

Security and Defense Systems n Highly rugged and mobile tactical fiber optic cables and systemsn Perimeter security monitoring fiber optic cables and systemsn Fire prevention, detection and suppression fiber optic cables and systemsn Integrated fiber optic and power cable for remote communications with power supply

Low and Medium Voltage Cablesn XLPE and EPR polymer LV cables with copper or aluminum conductorn XLPE and EPR polymer MV cables with copper or aluminum conductorn Accessories and support services

High Voltage Systemsn Complete installations from 69 kV to 500 kVn XLPE polymer and LPOF cables with copper or aluminum conductorn Consulting and engineeringn Project management, installation and commissioning

High Voltage Accessoriesn Accessories for all XLPE and oil-filled cables from 69 kV to 500 kVn Transition joints for connecting XLPE and oil-filled cables n Accessories suitable for the cables of all leading manufacturers

Telecomn Metallic fiber optic cables and ropes, including optical groundwire (OPGW)n All-dielectric, self-supporting (ADSS) aerial fiber optic cablesn Fiber optic outside plant (OSP) cablesn Consulting and engineering for complete system solutionsn Installation training

Brugg Cables is an international leader providing customers with a full selection of innovative products. Our quality and management systems conform to stringent ISO 9001 and 14001 requirements.

Designation Fiber Count (Max.)

Diameter(in)

Fault Duty (kA2s)

RBS (lbs)

Weight (lb/ft)

Area (in̂ 2)

Sag 10Chart

27AY59ACS-1C 16 0.472 46.3 16,536 0.305 0.13 1-1457

32AY54ACS-1C 16 0.472 48.1 15,613 0.293 0.13 1-1461

64AY37ACS-1C 20 0.512 75.1 13,987 0.286 0.15 1-1455

34AY73ACS-1C 24 0.528 68.9 21,771 0.395 0.16 1-1427

39AY68ACS-1C 24 0.528 74.8 19,468 0.365 0.16 1-1461

39AY68ACS-1C 24 0.528 71.9 20,620 0.380 0.16 1-1457

34AY74ACS-1C 24 0.531 74.1 20,928 0.386 0.16 1-1457

68AY42ACS-1C 24 0.534 88.0 15,529 0.316 0.16 1-1170

31AY87ACS-1C 24 0.555 84.5 24,105 0.438 0.17 1-1427

44AY75ACS-1C 24 0.555 91.7 21,555 0.404 0.17 1-1461

75AY44ACS-1C 24 0.555 103.9 16,455 0.337 0.17 1-1455

59AY66ACS-1C 24 0.571 109.8 20,098 0.391 0.18 1-536

79AY46ACS-1C 24 0.571 116.2 17,402 0.356 0.18 1-1455

27AY59ACS-2C 32 0.472 41.9 15,310 0.293 0.12 1-1450

59AY27ACS-2C 32 0.472 49.4 10,692 0.232 0.12 1-1439

86ACS-2C 32 0.472 28.8 20,851 0.366 0.12 1-1140

40AY100ACS-1C 36 0.602 118.0 26,909 0.502 0.20 1-1453

56AY83ACS-1C 36 0.602 123.1 25,716 0.479 0.20 1-1450

103AY40ACS-1C 36 0.606 153.9 17,073 0.368 0.21 1-1441

101AY59ACS-1C 36 0.646 190.1 21,902 0.454 0.24 1-1455

84AY76ACS-1C 36 0.646 179.7 25,249 0.499 0.24 1-536

27AY59ACS-3C 48 0.472 37.7 14,083 0.281 0.11 1-1461

32AY54ACS-3C 48 0.472 39.2 13,159 0.269 0.11 1-1444

59AY27ACS-3C 48 0.472 43.3 10,389 0.232 0.11 1-1439

67AY32ACS-2C 48 0.506 62.9 12,292 0.267 0.13 1-1439

34AY73ACS-2C 48 0.528 65.1 19,090 0.365 0.15 1-1450

34AY74ACS-2C 48 0.531 67.0 19,376 0.370 0.15 1-1450

49AY85ACS-2C 48 0.591 106.4 22,478 0.435 0.19 1-1461

67AY32ACS-3C 48/72 0.506 54.4 11,915 0.267 0.13 1-1455

40AY100ACS-2C 48/72 0.602 104.9 24,642 0.476 0.19 1-1457

101AY47ACS-2C 48/72 0.620 146.6 18,418 0.397 0.21 1-1439

101AY59ACS-2C 48/72 0.646 167.8 21,336 0.451 0.22 1-1170

110AY51ACS-2C 48/72 0.646 172.4 19,662 0.428 0.22 1-1439

59AY101ACS(27)-2C 48/72 0.646 155.9 24,617 0.517 0.22 1-1427

191AY45ACS-3C 72 0.785 426.6 19,735 0.504 0.34 1-1056

37AY92ACS-3C 96/108 0.577 78.7 21,020 0.417 0.16 1-1450

49AY91ACS-3C 96/108 0.602 97.2 20,684 0.427 0.18 1-144

101AY59ACS-3C 96/108 0.646 146.8 20,774 0.448 0.21 1-917

194AY74ACS-3C 144 0.836 498.6 23,121 0.599 0.37 1-1056

This chart offers a brief overview of popular Brugg OPGW designs and merely hints at the full range of mechanical and electrical properties of

our cables. Many other designs are available. For additional details speak with your Brugg Cables representative.

Cable data files for use with PLS-CADD and PLS-CADD/LITE are available at: http://www.powline.com/files/cables/brugg.html*All Brugg designs conform to IEEE 1138.

** Brugg cable and stringing guidelines are consistent with IEEE 524 requirements, which is a standard for construction of all types of overhead powerlines.

Brugg Cables, LLC25 Anderson RoadPO Box 5231 • Rome, GA 30162-5231Phone: 706.235.8755 Fax: 706.235.7635Email: info.usa@brugg.comwebsite: www.bruggcables.com

Brugg Kabel AGKlosterzelgstrasse 285201 Brugg SwitzerlandPhone: +41 56 460 3333Fax: +41 56 460 3536Email: info@brugg.comA Company of the Brugg Group Brugg Cables_ OPGW 0310

BruggOPGW Design Overview

Well, has your company had any of the following problemswith your OPGW?

Lost time and safety hazards from having to use an anti-rotation device.

Unnecessary extra splice points because of restrictive pulling limitations.

Fibers going dark or showing increased attenuation or PMD well before the cable’s 40-year life expectancy.

Consider the Brugg alternative and get the better value for your company by far!

Brugg OPGW offers far better value because our cable offers you lower overall installed cost of the cable, accessories, stringing, and splicing coupled with superior long-term reliability. In addition you also benefit from a lower total life cycle cost.

Not all OPGW is created equally. Just consider these innovative features of Brugg OPGW:

Torque balance

Our fully stranded stainless steel loose tube (SSLT) designs minimize torque which means that you can string Brugg OPGW without using a “gator” or “monkey tail” anti-rotation device (ARD) which makes stringing faster, safer, and hassle-free. And saving time means saving money!

Greater flexibility and crush resistance

Brugg fully stranded SSLT designs offer superior flexibility and crush resistance. So you can pull them faster, farther, through more angles and use smaller stringing blocks. Contractors estimate they save two hours per reel with our OPGW. And Brugg SSLT designs offer fewer splice points and less pulling set-ups, creating significant savings in time and money.

In addition, by reducing the number of splice points your optical link is improved as well.

Higher fiber strain margin.

Our fully stranded SSLT designs have a zero fiber strain margin equal to at least 80% RBS. So your fiber will never actually take any of the tension on the cable itself even during the most severe design load conditions. This means greater long-term optical reliability and no fibers going dark or showing increased attenuation or PMD. So, how exactly do we achieve all of this? Examine this cross section of a typical Brugg OPGW design and see for yourself.

Unlike other OPGW designs in the market it more closely resembles the cross section of a standard ACSR or AAC type cable. But we offer other interesting advantages as well.

Brugg SSLT’s use a conservative fill factor

We don’t try to overstuff our tubes with fiber. Cramming a tube with fiber reduces “excess fiber” or “fiber overlength” by limiting the room for the sinusoidal lay you want the fibers to have in the tube. By reducing fiber overlength you lower your cable’s zero fiber strain margin.

Brugg under-sizes the SSLT’s relative to the wire around them

By doing this we increase the cable’s crush resistance.

Brugg always has at least one wire between our SSLT’s.

This creates a bridge-like effect over the tubes and further increases our cable’s crush resistance.

Brugg uses proper fit, conservative lay lengths, and superior wire preforming to ensure torque balance and flexibility, and to further enhance zero fiber strain margin. This wraps up the obvious sales pitch. Now how about some useful tips on what you need to consider to best specify your own OPGW?

Consider this — OPGW has three distinct aspects:

Mechanical/Structural — As a structural component of your transmission line.

Electrical — As both a shield wire to protect your phase conductors and as a ground wire, especially in the event of a fault on your system.

Optical — As a telecommunications medium.

Here’s the BRUview on each of these important areas.

Mechanical/Structural

In one regard, OPGW is just another cable attached to the structures supporting your transmission line. The tension the cable will have must be considered in your structural design, and its sag must be such that code clearances are maintained. The way that Brugg can best optimize a design for you is for you to give us your design conditions along with the sag and tension limits that you are working to meet. We then can determine the best design to meet your criteria.

Our approach works a lot better than just giving us some minimum rated breaking strength (RBS) or maximum weight to work with. How do you know that such values are really optimal? You are better served by taking full advantage of our engineering expertise.

Another consideration mechanically speaking is the diameter of the cable. We find that some of our customers take a “one size fits all” approach. They have one diameter for their OPGW for all conditions and all fiber counts. Others have a hodgepodge of diameters resulting from using a different cable design for every project.

We think there’s a better way in the middle ground. After all, does your company use only

one size ACSR? Nope. Nor do you use every single one in the book. Rather, your company has standardized on a handful of sizes for your transmission applications. In a similar way your company can standardize on perhaps two or three OPGW diameters. Perhaps one specification for high fault current conditions or where you need a high fiber count, and another for more typical fault current conditions or where a lower fiber count is suitable.

To facilitate smooth, safe, and fast stringing, we also recommend that you require that your OPGW be capable of being installed without the use of an ARD. In addition, you should be able to pull it in with tension up to 20% RBS and through a sum of all line angle changes of at least 360° including up to at least two each 90° angles.

Electrical

Fault Current

It is critical that you specify an appropriate value for the fault current capacity of your OPGW. This capacity is determined using this equation:

Current² (in kA) x time (in seconds) = kA²·s

Most of our customers base the current on what would be induced on the cable under a three phase fault condition, but a few use just a single phase fault condition.

We see much more variation in what customers use for the time. Some are conservative and assume 20 – 30 cycles to account for the possibility that the primary protection system could fail, and the fault could then persist for this long until the back-up protection cleared it. Others assume 8 – 12 cycles based upon the assumption that the primary system will clear a fault in 4 – 6 cycles, then the system will attempt to re-close, and if the condition that initiated the fault is still present, then there will be another 4 – 6 cycles before the line trips out completely. A few customers assume just 4 – 6 cycles for clearing.

What parameters you choose is actually a function of your design philosophy, and more specifically, your acceptable threshold for risk.

In addition to coming up with a capacity, you need to establish ground rules for how a cable’s capacity will be computed. We suggest that you require that all your vendors use the methodology in IEEE 738. Key variables in this are both the initial temperature and the final temperature of the cable. 40°C (104°F) has been commonly used in the U.S. This represents a realistic cable temperature on a hot, sunny, summer day in most of the country. 210°C (410°F) has commonly been used as the final

temperature. This is a conservative value, but somewhere above about 220 – 230°C aluminum alloy wires can begin to anneal and there could be adverse affects on the optical unit of any OPGW design or on the fiber cladding. You also need to make it clear that the final temperature should be defined as being at the “hottest part of the cable.”

You may be wondering now, “Why can’t I just say equivalent to 3/8” EHS or 7#8 or some other conventional groundwire cable?” Actually, there are two reasons.

First, this is simply too vague. There is no generally accepted published data as to what the fault current capacities of such cables are. And what upper temperature limit to use is open to debate.

Second, if you make some assumptions and crunch the numbers, you may be surprised to find that the capacities of such cables are relatively low compared to what you will find you actually need for your system. For example, 3/8” EHS is in the range of 10 – 16 kA²·s and 7#8 is around 27 – 39 kA²·s. Keep in mind that these cables became standards decades ago when the demands on our power grid were much lower than they are today.

Lightning

Brugg believes good lightning performance follows inherently from good design for fault

current capacity. But we can still share our thoughts and observations about this subject.

Surprisingly, there is no generally accepted standard regarding designing OPGW for lightning. There are tests that purport to simulate lightning performance. However, these tests are based upon testing regimens developed by the military and aerospace industry for protecting aircraft from control systems malfunction after a strike. It is highly debatable whether such tests should be carried over to cables such as OPGW. For one reason, an aircraft obviously is likely to be in the immediate proximity of a cloud initiating a stroke whereas an OPGW or shield wire will be much further away. In contrast, lab testing is typically done with a cable a few centimeters away from the source. Despite the limitations of available testing one can still make three general observations.

All else being equal, size does matter

All else being equal, a larger wire is less likely to be seriously damaged by a lightning strike than a smaller one. So, a 3 mm wire will perform better than a 2.5 mm one, and a 4 mm one will perform better than a 3 mm one. But there are trade-offs. Larger wires create larger and heavier cables. This means shorter reel lengths, more splice points and higher cable costs. And larger wires impact the cost of various accessories used and transmission line structures as well.

Some utilities do adopt minimum wire sizes, sometimes just for the outer layer, such as 2.8 mm or 3 mm or even larger. The smallest size we use is 2.4 mm and our OPGW designs have an excellent field record. Though we simply do not believe that minimum wire size restrictions are necessary— you’re the boss. No matter your needs we can design a cable to fit your requirements.

Material matters too

Once again, all else being equal, material matters too. Galvanized steel wire actually performs better than aluminum-clad steel (ACS) wire. ACS wire performs better than aluminum-alloy wire. This too, needs to be considered in the light of trade-offs in other important properties such as strength, weight, conductivity, and cost.

Footing resistance

We have noted anecdotally that utilities that make a concerted effort to have low footing resistance also have fewer incidences of lightning damage on their lines.

As indicated previously, Brugg believes that if one designs appropriately for fault current capacity, then good lightning performance will follow as a consequence.

So, think you reallyknow all about OPGW ? Seriously?

Optical

The most basic issue regarding the fiber itself is how many fibers are to be in the cable. In fact, Brugg regularly receives inquiries for OPGW that give nothing else besides the fiber count. Though 48 is the most common count, we make many cables with 24-fibers, some at 12, 72 and 144, and a few at 32, 36, and 96.

The most common fiber type that we work with is “low water peak” type matched-clad single mode per International Telecommunication Union — Telecommunication Standardization Sector (ITU-T) standard G.652.D. Basically, this is a “new and improved” version of the original matched-clad type of single mode fiber which had a noticeable increase in attenuation between the 1310 nm and 1550 nm operating wavelength windows. This was known as the “water peak.” Through improved manufacturing processes, suppliers have been able to substantially reduce or eliminate this which gives at least one additional operating window. Specific examples of the “low water peak” type fiber include Corning SMF-28e+® and OFS AllWave® ZWP. We find that fibers from different manufacturers are very similar. In the field, they are indistinguishable, and more importantly, they are generally splice compatible with one another.

Some customers will use non-zero dispersion shifted (NZDS) single mode fiber on projects traversing distances greater than 50 – 60 miles or so, or where dense wavelength division multiplexing (DWDM) will be used to increase data transmission capacity. These fibers are governed by ITU-T G.655.C. Perhaps the two most commonly used NZDS fibers are Corning LEAF® (Large Effective Area Fiber) and OFS TrueWave® RS ZWP. Unlike with plain single mode fiber, NZDS fiber from different suppliers do not generally work well with one another. So once you have picked one, you will be best served by continuing to use it.

Brugg has several customers that use a mix of standard single mode fiber and NZDS fibers. For example, we have made cables with 36 regular fibers plus 12 NZDS ones. We also have a few customers that use multi-mode fibers. When this fiber is chosen 62.5 µm is most commonly used, but 50 µm is also readily available. Here again, we can make a cable with a mix of multi-mode and single mode fibers.

Regarding attenuation limits, we recommend you specify your maximum, individual fiber limits after cabling and particularly suggest limits of 0.35 dB/km at 1310 nm and 0.22 dB/km at 1550 nm, as limits

of 0.4 and 0.3 dB/km were rendered obsolete many years ago.

The preceding is just the basics about fiber. There is much more that you should consider. Specifically, you ought to think about zero fiber strain margin, polarization mode dispersion (PMD), and fiber identification. We shall discuss each in turn.

Brugg believes that zero fiber strain margin is essential for long-term reliability. This margin is the difference between the tension on the cable and when the fiber itself first picks up any of that tension. There are two sources for this margin, and this is true for any OPGW design.

1. “Excess fiber” or “overlength” in the buffer tubes

In Brugg “fully stranded” OPGW, we achieve a margin equal to approximately 20% of the rated breaking strength (RBS) of the cable from the tubes.

2. “Helix factor” imparted in the tubes from stranding them

In Brugg “fully stranded” OPGW, we achieve a margin equal to approximately 60% of the RBS of the cable from stranding.

It is a fact that “center tube” type OPGW designs only have the first source and therefore commonly have lower zero fiber strain margin.

So why is this important? Consider your design conditions. Typical “everyday”(no ice, no wind at 60°F) final design tensions are between 10 – 20% RBS. The NESC permits fully loaded conditions to be up to 60% RBS initial. And under newer “extreme” wind and ice loads tensions can be even higher. In our “fully stranded”designs, Brugg guarantees a minimum margin of 80% RBS. This means that the fiber will never experience any tension during operation. Thus, long-term reliability is ensured. No straiN = No problem!

Consequently, we recommend that you specify your OPGW have a minimum zero fiber strain margin of 80% RBS. Even if you want to allow “center tube” type designs, you can still require a minimum margin of 50% RBS because this can be achieved by increasing the overlength in the tube.

PMD is a long-term problem that results from non-circularity in the fiber coupled with fiber strain. The non-circularity causes the light become polarized as it is transmitted through the fiber. In turn, this causes signal corruption and can lead to lower data transmission rates. Fiber strain exacerbates the non-circularity,

so if you eliminate fiber strain, then you also eliminate the possibility of increasing PMD and its associated adverse effects. Consequently, we suggest that in addition to specifying a minimum fiber strain margin, you also specify PMD ≤ 0.2 ps/√ km.

In many of today’s fiber optic cables, there will be more than 12 fibers per buffer tube. How then does one identify them all? We use band marking because it leaves the fibers free to move within the buffer tubes and is therefore consistent with the loose tube design concept. In contrast, bundling fibers into groups of twelve using binder strings restricts fiber movement and thereby undercuts a major benefit of the loose tube design concept. Therefore, we recommend that you require band marking when more than 12 fibers will be in a single buffer tube.

Closing Thoughts.

Brugg pioneered the use of stainless steel loose tubes (SSLT’s) in aerial cables, including OPGW, in the early 1990’s. Now, SSLT-type OPGW in one form or another is offered by almost every OPGW supplier in the world, most notably our largest competitor here in the US. As the old saying goes, “Imitation is the most sincere form of flattery.”

If you have to use “kid gloves” when installing Brand X cable, then is it really that good? More importantly how will it really hold up in the air? brugg opGW is proven in the field.

You need more than just cable to get your system installed. Brugg works with major hardware suppliers, and we’ll help you specify or even supply all the accessories that you’ll need. Watch out! Some may offer you cheaper cable but then require that you buy expensive accessories. Is that really what you call value?

You need more than simply cable and accessories to get your system installed— you need expertise. Which is why Brugg provides a free one-day on-site installation training class. Call on us! We provide lots of free engineering support from our Rome, GA manufacturing facility. Pick our brains and try us out anytime!

Make Brugg your choice for quality OPGW cabling solutions today!

Brugg OPGW provides greater torque balance during the stringing process eliminating “monkey tails” and “gators”. Such devices can greatly increase the cost of stringing and result in bad cable installation—which leads to performance loss and shortened product life expectancy.

No moNkey tails!

SSLT ( Stainless Steel Loose Tube )ACS ( Aluminum-Clad Steel )AY ( Aluminum Alloy Wires)

SSLT

ACS

AY

Basic Design Of Brugg OPGW