Volume 1, Issue 1
CORTINOVIS MACHINERY AMERICA, INC.
Eurolls
Group News
1st Qtr 2012 Electric Power: The Engine That Drives Economic Growth OVERHEAD ALUMINUM CONDUCTORS: MARKET TENDENCY & HOW CORTINOVIS SICTRA IS RESPONDING TO THE INCREASE IN DEMAND Developing nations, in order to grow their economies, need reliable and economic solutions to their energy requirements. Unfortunately, the road to energy independence is not always easy. Laws need to be written, regulations need to be put in place, environmental concerns need to be considered and sound engineering solutions need to be developed in order to get the energy where it is required in the most efficient manner. UPCOMING EVENTS This discussion will concentrate on the specific cables utilized to distribute this energy, the developments in cable designs and the equipment required to produce these cables. We will describe the current trend in the overhead conductor market and how CORTINOVIS MACHINERY and SICTRA, companies, which belong the same group (EUROLLS GROUP), have developed technologies proven to increase the production capabilities of manufactures already present in the market and also provide know how to companies that are considering entering the market but have been reluctant due to deficiencies in market knowledge and production capability. We will describe the two essential processes that are required to produce these conductors; Wire Drawing and Stranding. Product Solutions: th
From the beginning of the 20 century AAC (All Aluminum Conductor) was the only solution used for overhead conductor. This remained constant until just before WWII when the use of AAC was exceeded by AAAC (All Aluminum Alloy Conductor). The change was brought about because of the need for a higher conductivity conductor with higher strength. Unfortunately, it was determined that the strength of the conductor was the real limit. This remained the limitation until the introduction of ACSR (Aluminum Conductor Steel Reinforced) and ACAR (Aluminum Conductor Aluminum Alloy Reinforced). Today’s market is demanding even higher performance conductors, and the research is concentrated in the following areas: 1.
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WAI Operations Summit
& Wire Expo
May 22-23, 2012
Omni Dallas Hotel |
Dallas, Texas, USA
Stand 416
Smaller diameter conductors with the same conductivity value Lower resistance conductor material for higher conductivity Higher strength for conductors reducing the conductor’s weight with the same conductivity level We will attempt to explain how the constructions have evolved, the reasons for the evolution, and finally the equipment required to manufacture these products. There are five major types of overhead conductors used for electrical transmission and distribution: 1.
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AAC AAAC ACSR ACAR ACCR All Aluminum Conductor All Aluminum Alloy Conductor Aluminum Conductor Steel Reinforced Aluminum Conductor Aluminum Alloy Reinforced Aluminum Conductor Composite Reinforced AAC – All Aluminum Conductors Stranded 1350 aluminum conductors are classified, as follows: •
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Class AA: For bare conductors usually used in overhead lines. Class A: For conductors to be covered with weather‐resistant materials and for bare conductors where greater flexibility is required. Class B: For conductors to be insulated with various materials and for conductors indicated under Class A where greater flexibility is required. Class C: For conductors where greater flexibility is required. Compact strand conductor for use in bare overhead applications or for use with weather‐resistant coverings or insulations are also available. AAAC – All Aluminum Alloy Conductors Used as bare overhead conductor for primary and secondary distribution. Designed utilizing a high strength aluminum alloy to achieve a high strength‐to‐weight ratio; affords better sag characteristics. Aluminum alloy gives AAAC higher resistance to corrosion than ACSR. ACSR – Aluminum Conductor Steel Reinforced ACSR is a high‐capacity, high‐strength concentric‐lay‐stranded conductor consisting of a single core wire or a stranded steel central core with one or more layers of 1350 H19 stranded aluminum wires typically used in overhead power lines. The outer strands are aluminum, chosen for its excellent conductivity, low weight and low cost. The center strand is of steel for the strength required to support the weight without stretching the aluminum due to its ductility. This gives the cable an overall high tensile strength. ACAR – All Conductor Alloy Reinforced Used as bare overhead transmission cable and as primary and secondary distribution cable. A good strength‐
to‐weight ratio makes ACAR applicable where both ampacity and strength are prime considerations in line design. For equal weight ACAR offers higher strength and ampacity than ACSR. ACSR‐TW ‐ ACSR with Trapezoidal Aluminum ACSR/TWD is ideal for replacement of existing conductor: it offers the same diameter for ice and wind but loading at higher ampacity than traditional ACSR designs. Angle and deadened structures must be carefully evaluated because of the greater weight of the conductor. The same tangent structures may normally be used in installation. Zinc (Zn) Coated Steel Wire Core The steel wires are coated with zinc to improve corrosion resistance. The technology used is either “hot dip galvanizing” or “electro‐galvanizing”. Hot dip plating involves passing the steel wire through a molten zinc bath whereas electro‐galvanizing involves electroplating. Galfan, which is Zn‐5% AL, is the most rapidly growing hot dip process and provides improved corrosion resistance over conventional Zn. Once coated, the wire can be used as is or can be redrawn. The wires are stranded to produce a single wire, 7‐wire or 19‐wire core. Using ACSR & ACCR with Shaped Conductors The latest evolution in overhead conductors since the introduction of conventional Aluminum Steel Reinforced Conductor (ACSR) is the development of a strand using shaped wire instead of round wire aluminum conductors in combination with composite core. Due to its light weight and high strength, this core, patented by 3M, can provide a cable with transmission capacities from two to three times greater than those of existing systems. The high‐performance 3M brand composite conductor is known as ACCR (Aluminum Conductor Composite Reinforced). In addition, regarding the current carrying material, the tendency nowadays is to use Aluminum Alloy. However, more often we find customers using Aluminum Zirconium Alloy which has a greater thermal limit. It does not matter if the project is in an industrialized area or big city, most of the points that are pushing the companies into shaped wire conductors can be summarized in using the following points: 1.
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Very high cost to install new power line Too difficult to acquire new tower sites and right of way Time constraints where for some projects there is not enough time to build a new site Popular feeling against construction of high voltage overhead lines in urban and suburban areas Why Shaped Wires: Each trapezoidal segment must be specifically designed for each cross section and each layer within the cross section. If you then consider the geometries of the numerous strands, the manufacturing cost to produce these trapezoidal segments is higher than producing conventional round wires. So why would you do it? The objective is to manufacture strands with max possible reduction of interstices, the free space between the wires. Traditionally this is accomplished by compacting the strand after it is formed. Unfortunately, this process is limited to compacting ratios of 90‐92%. To achieve these compaction rates, capstans which can produce sufficient pull to compact the strands are required. Furthermore, while the smaller cross sections can be produced efficiently the larger cross sections become problematic. Therefore, since the objective is to reduce the space between the wires by deforming them, it stands to reason that if you start with a deformed, trapezoidal wire the amount of work needed to produce the compacted conductor is reduced significantly. But why shaped conductors? The answer becomes obvious if you consider the following: If you produce a given cross section, and you use trapezoidal wire, the diameter is smaller. This in turn means that all the downstream equipment which is diameter sensitive can be reduced. For example: If the product requires insulation, you will use less plastic. If the cable is eventually cabled into a triplex or a quad it will also be smaller in diameter. See the example below: EQUIVALENT DIAMETER Instead of manufacturing a smaller diameter conductor for the “equivalent” circular area, the design of the trapezoidal shapes can be enlarged and yield a greater cross‐sectional area of aluminum and matching the diameter of the original conventional round conductor. The resulting conductor has the same diameter as the conventional conductor, but with a much larger Aluminum cross‐sectional area, this means you can increase the Aluminum content by 20‐25%, decreasing the AC resistance by 15 to 20% and significantly increase the current carrying capacity of an existing line. However, if the objective is to increase current carrying capacity and you are not attempting to decrease diameter you can increase the cross section while maintaining the same diameter. See the example below: EQUIVALENT AREA Trapezoidal conductors utilize aluminum pre‐shaped wires prior to stranding to provide a smooth outer surface and fit together to reduce the interstitial empty space and finally to allow a smaller overall diameter of the conductor. Trapezoidal conductor has the same Aluminum cross‐sectional area as the Conventional conductor, but with smaller overall diameter. The result is a conductor that has a diameter approximately 10% smaller. Therefore you can increase the cross section and increase the current carrying capacity and still maintain the same diameter. Traditional conductors, ACSR (Aluminum conductor steel reinforced) using round conductors are being substituted with newly developed products such as: •
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ACSR/TW (Aluminum conductors steel reinforced/trapezoidal wires with internal gap) ACSS/TW (Aluminum conductors steel supported/trapezoidal wires) ACCR (Aluminum conductors composite reinforced) Trapezoidal Gap Design “Self‐dampening” Alcan Cables In some cases, a high performing material with extra high conductivity Al Alloy, composite wires with oriented Alumina fibers in AL matrix (3M patented product can be used. What Benefit do you get from ACCR? Electric power is the engine that drives economic growth. As utilities continue to expand the electrical grid the demand for more power is ever increasing. In some cases additional power is required in mature areas where the replacement of existing infrastructure is just not economically feasible. But what if you could increase the amount of power you could deliver by changing the cable without having to change the towers. The 3M ACCR core is stranded from wires that are composed of Alumina fibers which are embedded into high purity aluminum. Compared to conventional ACSR, which has a steel core, the ACCR cable exhibits half the thermal expansion therefore less sag at high energy levels and has twice the strength to weight ratio. This enables you to produce a cable with the characteristics that result in two or more times the current carrying capacity in a cable that puts less stress on the structures. Also since the core is lighter, you can increase the amount of current carrying conductor and eliminate the need for new towers, land acquisition and the inherent problems with environmental impact by maintaining the same cable weight but increasing the current carrying to weight ratio. ACCR ‐ Aluminum Conductor Composite Reinforced Compared to the same diameter steel core conductor 3M ACCR can offer as much as: •
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Half the thermal expansion for less sag at high energy levels Twice the strength to weight ratio Operating temperatures up to 210°C continuous and 240°C emergency for up to 1,000 hours cumulative More conductivity These properties allow you to triple the capacity of your transmission line without adding tension or weight to your structures – maximum amps with no compromises. 3M ACCR is an advanced transmission conductor designed to replace ACSR on existing structures, giving you up to two to three times the capacity without the risks of a major construction project. •
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Reduce construction outages Speed up and simplify permitting Reduce project schedule Increase budget certainty Minimize new environmental impacts on existing rights of way Now that we have introduced the available solutions we need to understand the reason why the market is moving into trapezoidal Aluminum shape wire conductors. When considering an upgrade to an existing infrastructure or the installation of new power line, several constants are always present; the demand for more electricity in the most efficient way and the least amount of environmental impact must be considered. The solution for the above problem, in most cases, is RE‐CONDUCTORING of existing lines with high temperature & low sag conductors carrying higher power. This enables you to utilize the existing tower and in most cases the existing clamping, while still being able to have more power transmission capacity. New headquarters of Sictra and Cortinovis located in Valbrembo (BG) Sictra Wire Drawing: SICTRA is well known worldwide for its experience in the field of the wire drawing of non‐ferrous materials. Sictra has been part of The EUROLLS Group since 2008. In January 2011 Cortinovis Machinery integrated Sictra into the Cortinovis Company making it a separate wire drawing division within Cortinovis Machinery S.p.A. At this time we also took this opportunity to change our historical logo to a new one combining the two brands and their logos into a unique one while maintaining the brand and individual experience of each company. This continuity of the new division was maintained by retaining the original Sictra management and technical staff headed by Mr. Giorgio Monti. Mr. Monti is the original founder of Sictra with more than 40 years experience in the field. Today the new division continues the innovation of products enabling SICTRA to offer high quality practical solutions which have become a benchmark in the NON‐FERROUS wire industry. This continued commitment to the industry has resulted in numerous innovative solutions to the manufacturing equipment we produce for the wire and cable industry. Our main products include: Rod break down, drawing machines for single or dual wires, pay‐offs, annealers, and a variety of take‐ups for various solutions. For all types of the overhead conductors, the initial process will be wire drawing. The Sictra division has a full range of non‐ferrous wire drawing machines working successfully in the wire & cable industry all around the globe. In this writing we will present a new concept of Rod Break Down machine designed specifically for Aluminum and Aluminum Alloy for round, trapezoidal and shaped wire. Cortinovis Machinery Stranding: Cortinovis was established in 1881. In the early years, the company’s core business was a foundry for bronze and cast iron; the company also had a workshop where mechanical work was done as a subcontractor, mainly for manufacturing tools for small industries and for the agricultural industry. In the early part of the 20th century the company started to develop and design its own products and technology. From the 20’s to the beginning of World War II, the foundry and the workshop continued to develop, making the Company one of the most renowned foundries and mechanical workshops in the area. Immediately after World War II, Cortinovis took advantage of the close vicinity of one of the largest cable manufacturers, which was based in Milan and entered into the cable machinery business, a sector, which the Company would never leave. Cortinovis has introduced numerous new solutions, earning the reputation as a machinery producer of innovative designs and machines to fulfill customer production requirements. Cortinovis went on to establish worldwide presence in markets such as South East Asia, North and South America, Europe, and the Middle East. In order to serve these markets better we have established Cortinovis companies in the local markets such as Cortinovis Machinery America, Cortinovis Do Brazil and a service center in Cairo providing service to our customers in the Middle East. Recently we have set up an after sales organization in China in order to be able to provide a more efficient service to our Chinese and South East Asian customers. Together, our companies are able to supply a complete solution for upgraded the overhead conductor solution. “ Systems integration & responsibility to provide total systems solutions “ Total technical capabilities providing innovative high‐quality products and services “ In‐house experienced cable process engineers and manufacturing engineers “ Short decision chain ‐ to anticipate and take advantage of changes in the market “ Products tailored for the market Cortinovis Sictra – Your Complete Solution Supplier Once you have determined the best engineering solution for your power grid requirements. The first manufactured process will be to assemble the core. The stranded central core is prepared using a specialized piece of equipment such as a Cortinovis Tubular Strander. At the exit of the Tubular Strander a special performer device is required for steel, galvanized steel wire and Aluminum Clad steel wire to form the wire into the required helix. The Tubular Strander can also be used as an alternative to the rigid strander to complete the stranding of the Aluminum or Aluminum alloy into the finish conductor. However, the Tubular Strander must be equipped with a driven articulating joint for central core, a cradle with suitable braking system, shallow deviating angles for the wires and central core and finally the wire passages must be increased to accommodate the galvanized wires and the core diameter. PATENTED Rotating Joint Device Required for center core in the second pass of the core 1+6+12 However, for larger cross sections the preferred stranding machine for the construction of the overhead conductor is the rigid strander, typically with 54 bobbins with a diameter of 630mm. Once you have settled on a core design you need to prepare the wire to be stranded around the core, the wire can be round, trapezoidal or shaped. To manufacture the above shapes a SICTRA ROD BREAK DOWN machine can be used to draw the specific wire. The Sictra Rod Break Down line integrates a pay‐off system which is selected according to the material being processed (Aluminum or Aluminum Alloy). The Rod break down machine itself can be a gear driven type with a single motor or multi‐motor type which includes a motor at each draw capstan. This selection is also based on the material being processed. Sictra offers a wide range of Rod break down configurations each available with a different number of passages. The flexibility of the Sictra machines gives the customer the opportunity to customize the line for each specific product requirement. This flexibility of design and wide range of technologies is what has distinguished the Sictra machines in the world. For this specific application the most highly recommended machine is one with completely submerged capstans. Since the capstans are submerged in a solution, the foaming problem, which is caused when air is taken into the drawing lubricant/oil by the capstan while rotating is avoided. This foaming is quite commonly attributed to machines with partially submerged capstans The submerged capstan approach becomes particularly important when considering in‐line Aluminum annealing process system (normally not required for overhead conductors). Since the aluminum is never exposed to air, wire oxidation inside the drawing section is prevented. Our die‐holders design includes a hard metal pre‐drawing die location before each drawing die. This system (pre drawing die and drawing die) insures that the wire approaches the drawing die perfectly aligned. This is a useful feature when drawing shaped wire since the quality of the wire is improved and life of the drawing dies is extended. Another important feature is the design of the drawing rings. The Sictra drawing rings have a special conical/biconical surface to prevent the shaped wire from overlapping. We also include a die holder in the top for free access during string up. The following is a typical die setting for shaped wire starting with an entry of 9.5mm Aluminum rod: Trapezoidal shaped wire has to be specially designed for each section and each layer, considering the geometry of the strand. Depending on the final section you wish to achieve, a different selection of round and shaped dies will be used. If you select a controlled slip drawing machine the total wire will be decreased since the slippage is not cumulative like in the traditional gear driven machine. The result of less slip is less capstan wear. In addition, controlled and reduced slip machines produce superior surface quality as well as reduce noise level. Our twin Rod Break Down machine which is equipped with two independent final capstans gives the possibility to produce two different diameter wires at the same time. Furthermore you can also produce one round wire in combination with a shaped trapezoidal wire. This solution gives you the possibility to maximize your production, without compromising, the production since the two lines are in production simultaneously with different speeds. Our multi‐motor Rod Break Down machine is suitable for drawing materials with different elongations with controlled slip. This would be advantageous for producers who want to draw Aluminum as well as all different kinds of Aluminum Alloys Once the wires are drawn and placed on bobbins, we then turn our attention to stranding. When considering shaped wire stranding, small adjustments on our standard stranding machine are required. The machine must be equipped with a suitable pay‐off unit for central core. This payoff must provide a smooth transition from the bobbin to the Stranding line while maintaining a constant tension on the core. The core enters the first cage of the Rigid Cage Strander where it assembles the trapezoidal wires made on the Sictra Rod Break Down machine around the core prepared on the Cortinovis Machinery tubular strander to form a 6 wire layer. Once the product exits the 6 bobbin cage it enters the second cage (12 bobbins) where an additional 12 trapezoidal wires made on the Sictra Rod Break Down machine are placed over the previous wire layer to form a 12 wire layer. At the exit of each cage a special device is required for trapezoidal and shaped wires to maintain the trapezoidal shaped wires oriented according to the position in the strand. For cables made from round wire and whenever Aluminum alloy material is selected, a performer is required. In addition a special lay plate and lubrication are required at the die stand to complete the process. Finally, a larger capstan with round grooves is recommended. Internal view of the final cable composition Our technical capabilities and our experienced cable process engineers can assist our customers with total project management which includes the selection of the proper equipment, installation requirements, supervision of the installation and production trials. AT CORTINOVIS SICTRA WE BELIEVE THAT OUR SUCCESS IS YOUR
SUCCESS
Our facility in Monterey, Mexico (EUROLLS DE MEXICO) can handle the production of new TUNGSTEN CARBIDE rollers and can regrind worn rolls that are no longer in tolerance. Our Mission Innovative solutions in Stranding and Cabling that can handle the increased productivity requirements, take advantage of the latest technological advances, improve process efficiency, and reduce downtime. Technology Through intelligent design, based on years of experience in the rotating machinery market, we can supply a comprehensive solution to the complex cabling requirements of today and tomorrow. Partnership We consider each and every customer to be a potential lifelong partner. Through this type of partnership, we work together for the benefit of both organizations. We will continue to supply high value added, high quality products and services and the measure of our success will be……. Total Customer Satisfaction 1014A Route 173 Bloomsbury, N.J. 08804
Phone: 908-479-9818
Fax: 908-479-1644
E-mail: Cortinovis@cortinovisamerica.com
Website: Cortinovisamerica.com
All of the Eurolls Group Companies which include Eurolls SpA, Cortinovis Machinery SpA, Teurema S.L., Sictra Spa, and Vitari SpA are exclusively represented by Cortinovis Machinery America, Inc. in North America.