CTC Global Technology – Take a Glance

The CTC Global Technology that we use, develops, tests, and commercializes the ACCC® Conductor and ancillary hardware components that improves the efficiency, capacity, reliability and resiliency of the electric power grid. The CTC Global Technology provides ACCC Conductor that is based on advanced composite technology initially developed for aerospace and other highly-demanding applications where superior performance and longevity are mission critical. The ACCC Conductor uses a high-strength composite core consisting of carbon and glass fibers embedded in a toughened thermoset resin matrix. CTC Global holds numerous U.S. and other international patents for its technology including the ACCC Conductor, the ACCC Composite Core, ACCC Conductor Hardware components and methods of manufacturing. CTC Global’s technical team continue to raise the performance bar to provide its customers with the most advanced and cost effective overhead conductor solutions available.

ACCC® Conductor

The CTC Global ACCC® Conductor utilizes a hybrid carbon and glass fiber core embedded in a high-performance thermoset epoxy matrix. The central carbon fiber core consists of tens of thousands of high-strength, high-modulus unidirectional carbon fibers that are surrounded by a protective layer of glass fibers. The outer glass fibers improve toughness and flexibility while also providing a galvanic barrier to prevent corrosion with the conductive aluminum strands.

The ACCC Conductor hybrid core is not only twice as strong as steel, it is also 70% lighter.

The lighter weight allows the CTC Global ACCC Conductor – of any size – to utilize ~28% more aluminum without a weight or diameter penalty. The compact trapezoidal strands and smooth surface composite core work in unison to dissipate wind-induced vibration. While the aluminum strands are fully annealed, offering the highest degree of conductivity for any aluminum available today, the composite core offers a coefficient of thermal expansion about ten times less than steel.

The low coefficient of thermal expansion mitigates conductor sag under heavy electrical load conditions. While the composite core is fully elastic and will not plastically deform or yield like conventional conductor steel core strands, the overall modulus of the CTC Global ACCC Conductor core is lower than that of steel. The lower modulus allows the ACCC Conductor to stretch degree during extreme ice and wind loading events. However, when the event subsides, the composite core fully returns to its pre-stressed condition allowing the aluminum strands to subsequently relax. This type of event further improves the ACCC Conductor’s self-damping characteristics and reduces the conductor’s thermal knee-point to further reduce conductor sag under heavy electrical load conditions.

In some cases pre-tensioning can be performed during installation to achieve these added benefits. When heavy ice and wind load conditions are anticipated, CTC Global and its worldwide stranding partners also offer a higher-modulus version of the composite core known as ULS. ACCC ULS Conductors are also frequently used on long spans. For more information please contact support@ctcglobal.com. You can also download an electronic copy of the 250 page “Engineering Transmission Lines with High-Capacity, Low-Sag ACCC Conductor”

ACCC® ULS Conductor

First deployed on a 1.4 kilometer lake crossing in Africa in 2013, The ACCC ULS Conductor offers greater strength, a lower coefficient of thermal expansion and higher modulus of elasticity than the standard ACCC Conductor core. The ULS version has a higher carbon fiber content raising the tensile strength from 313 to 375 ksi. While the added strength can enable longer spans, the higher modulus and increased stiffness reduce sag and blow out during high wind conditions. Improved stiffness can also reduce sag under heavy ice load conditions.

The higher carbon fiber content also reduces the coefficient of thermal expansion from 1.6 x 10-6 /°C to 0.75 x 10-6 /°C.

While dozens of engineers have specified ACCC ULS Conductor for projects, worldwide, the ULS version of the ACCC Conductor has served our clients well. The ACCC ULS Conductor is available in many sizes and offers designers added design flexibility.

The ACCC ULS Conductor can be ordered with Type 1350-O fully annealed aluminum or as an AZR version with Aluminum-Zirconium thermal resistant alloy for even higher overall conductor strength.

ACCC® AZR Conductor

ACCC AZR Conductor – Expanding the capabilities of the ACCC® Conductor using aluminum zirconium alloy

ACCC® AZR Conductor uses either the standard 310 ksi core or the higher strength 375 ksi core that is then wrapped with one or more layers of a high strength, thermal resistant aluminum-zirconium alloy. While conventional ACCC Conductors typically use fully annealed aluminum to maximize conductivity, the ACCC AZR Conductor offers nearly the same efficiency, but far greater overall strength. The added strength and increased tensile modulus mitigates conductor sag under heavy wind or ice loads, or very long spans.

ACCC InfoCore™ System

The ACCC InfoCore™ System reduces real-world conductor installation risk experienced by utilities, contractors and lineman across the globe. These dedicated professionals know that even with the best tools, equipment and field conditions, accidents can happen. By using a proprietary infrared light system, special fibers in the core, and a robust data-capture and recording methodology, the ACCC InfoCore™ System can confirm the integrity of the conductor in minutes. While not mandatory for every installation, this capability serves to improve reliability and confidence. The system is capable of confirming very long continuous spans and is currently being utilized globally.

CTC Global’s ACCC InfoCore™ System makes confirming successful conductor installation safe, simple and fast. Alternate methods include CT Scan, X-ray inspection, and magnetic pulse technology but these devices are very slow and expensive.

The ACCC InfoCore™ System is commercially available and has been deployed to a number of sites worldwide. It is noteworthy that there is no performance difference between ACCC® Conductor and ACCC InfoCore™ Conductor. ACCC InfoCore™ Field Verification Kits are easy to use, and available through CTC Global’s Master Installers network.

ACCC® Composite Core

CTC Global’s ACCC® Composite Core consists of high-strength carbon and glass fibers embedded in a toughened thermoset epoxy resin matrix. The composite core is manufactured to aerospace quality specifications using a continuous pultrusion process developed by highly skilled pultrusion experts. The ACCC® Conductor’s composite core offers a strength to weight ratio approximately six times better than steel, with a coefficient of thermal expansion about ten times lower. The composite core is also impervious to corrosion and cyclic load fatigue. CTC Global’s ACCC Conductor cores are currently available in 310 and 375 ksi tensile strengths. The higher strength version – referred to as ULS – also offers a higher modulus to accommodate longer spans and extreme ice loads. For comparison, extra high strength steel is rated at 285 ksi, but is approximately 70 percent heavier than the ACCC® Composite Core.

Quality Assurance

CTC Global certified to meet ISO 9001: 2015 standards

Quality you can depend on is a hugely important factor in our business. That’s why CTC Global ACCC® Conductor is produced with the highest quality standards throughout the manufacturing process. We’ve integrated quality assurance into every operation, and our Irvine, California operations are certified to ISO 9001:2015 standards by NSF International Strategic Registrations.

CTC Global manufactures all ACCC Products with complete traceability of material components, and every item is fully tested prior to leaving the factory. We ship every reel of completed composite core with a Certified Test Report that itemizes all the tests successfully completed and provides lot traceability.

All of our stranding sources are rigorously audited by our Quality Assurance organization, and must comply with ISO 9001:2015 standards. In order to be part of our supply chain, all stranding sources must gain a successful Quality Assurance audit report, and pass rigorous stranded conductor testing by both CTC Global and independent laboratories.

Environmental Responsibility

CTC Global certified to meet ISO 14001: 2015 standards

CTC Global has implemented and supports an effective Environmental Management program that ensures consistent dedication to corporate responsibility and environmental sustainability. We manage our facilities, processes, and materials in a way that meets or exceeds regulatory requirements and minimizes risk to the environment. We focus on the identification and continuously improving on all environmental aspects of product management taking into consideration the product lifecycle from start to finish. Our Irvine, California facility is certified to ISO 14001:2015 standards by NSF International Strategic Registrations.

How ACCC® Conductor Compares

ACCC® Conductor operates cooler, improves efficiency

In the past, T&D designers had few choices. All aluminum conductors such as AAC and steel reinforced conductors such as ACSR. In the 1970’s and 1980’s new conductors were introduced that could be operated at higher temperatures (to carry more current) such as ACSS. Additionally, Gap type conductor and Invar steel conductors were also introduced. While Gap conductor is a bit difficult to install and Invar conductors exhibit very high magnetic hysterisis losses, new composite core conductors were subsequently introduced in the early 2000’s. These included 3M’s ACCR conductor which replaced the conventional steel core strands with ceramic fiber reinforced aluminum strands and the CTC Global ACCC® Conductor which uses a single carbon and glass fiber (hybrid) core embedded in a high-temperature thermoset resin matrix to optimize performance and improve efficiency.

To assess the differences between different conductor types, Ontario Hydro in Canada performed a test at Kinectrics Lab. The test subjected the different conductors (Drake size equivalents) to 1,600 amps on a 65 meter (215 foot) test span. While the primary objective of the test was to compare conductor sag, the temperatures that each conductor reached under the 1,600 amp load also provided great insight in terms of each conductor’s efficiency. Notice in the graph below the differences in sag. Notice also how much cooler the ACCC Conductor operated under the same load condition. Cooler operating temperatures (from 60 to 80 degrees C) reflect a substantial improvement in efficiency. While many other manufacturers are beginning to recognize the advantages of the ACCC Conductor and its hybrid carbon fiber core, CTC Global’s expertise in composites and substantial field experience are unrivaled. If you are considering a high-performance economic solution, look no further. CTC Global offers performance and price advantages others can’t touch.