ACCC Conductor News    CTC Global     July 11th, 2012
 

 

Improving the Efficiency, Capacity & Reliability
of the Electrical Transmission Grid
 

City Power Johannesburg Completes Four Double Circuit Live Line Upgrades with ACCC Conductor

 

Quanta Services Installs ACCC Conductor Without Power Disruption

 

Growing demand on Johannesburg's 88kV Kelvin-Cydna transmission line called for the refurbishment and uprating of the lines from 100 MVA to 200 MVA. The existing steel lattice towers constructed in the mid 1950s were preserved through the use of ACCC conductor.

 

Due to heavy demand and outage constraints, City Power Johannesburg contracted US-based Quanta Services through its South African partner Edison Jehamo Power to upgrade the line while it remained energized.

 

Mott MacDonald Group member Merz and McLellan was selected to conduct the line survey, assess tower loading, analyze conductor options, study project economics and evaluate several other considerations. A number of high-capacity conductors and alternatives were considered, but CTC Global's ACCC Lisbon size conductor was selected as the most efficient solution.

 

Live line work, previously not performed outside the US, required installing an additional circuit (including new fittings, insulators and assemblies) to the existing towers and using transposition points to switch between circuits. Four circuits were kept live while the fifth was used to perform the upgrade. The two types of live line work used in this process were hotstick and barehand work. The former is used for tasks such as moving conductors, installing fuses and opening and closing switches.

 

Barehand work required the use of specially designed protective gear which enabled the linemen to work at the same electrical potential as the line itself. This approach can be used at voltages as high as 765 kV. The protective gear consisted of hooded jackets, overall-style pants, socks and gloves. They were made out of Nomex, a fire-retardant material, and stainless steel fibers. The metallic mesh provides a Faraday Cage like structure, which puts the lineman at the same potential as that of the conductor. With the protective gear coupled to the conductor, the lineman can work within the electric field.

 

Live line buckets were elevated to neutralize leakage current by touching a wand to the conductor. Linemen were then hoisted to the level of the conductors and Quanta Services' patented LineMaster robotic arm, remotely controlled by an operator on the ground, approached the conductor, which was trapped by means of a hotstick. Once all the lines were captured and the robotic arm had taken their weight, the insulation assemblies were detached. The robotic arm moved the conductors away from the tower and redundant fittings were replaced with new suspension assemblies bare-handed. The linemen were then equalized with the conductor which enabled them to install the new assemblies. 150 kilometers of ACCC conductor were installed earlier this year and an additional 100+ kilometers is currently being installed. An additional 175 kilometers of ACCC will be installed early next spring on City Power's grid using the same live-line methods.

 

Similar live-line ACCC reconductoring projects will begin later this year in the US and other countries next year.

Proven Reliability at over 210 Project Sites


The ACCC conductor's outstanding performance has allowed utilities worldwide to exploit its unique advantages while saving millions of dollars delivering more power, more efficiently, with reduced line losses, decreased fuel consumption and reduced generation emissions.  To learn more about how the ACCC conductor can work for you, please visit our new website at
www.ctcglobal.com

Jim Lehan, Sr Engineer, NV Energy shares his experience using ACCC conductor at IEEE/PES Meeting in Orlando  

 


NV Energy ACCC upgrade increases line capacity from 350 to 1,000 amps
 
Please watch Jim's video CLICK HERE 

The Economics of Efficiency 

 

While it is not uncommon to assume that the ACCC conductor, with its hybrid carbon and glass fiber composite core and added aluminum content (~28%), may, at first glance, appear to be more expensive than a conventional steel-reinforced conductor alternative such as ACSR or ACSS, its not too difficult to understand how the ACCC conductor's greater strength, increased electrical capacity and reduced thermal sag offer several benefits that can reduce upfront capital costs on new lines or reconductor projects, especially when considering potential structural savings.

 

Going beyond the obvious, as the three charts below describe, there are other substantial economic advantages associated with line loss reductions, generation capacity savings, and associated emission reduction savings (achieved by reduced fuel consumption).  The data presented below uses a 100 km (62 mile) example comparing ACSR under relatively light load conditions, as well as ACSS, under heavier loaded conditions, compared with ACCC.  In each comparison a conservative 53% load factor is used. Please note that the savings realized have been effectively translated into value per conductor unit length (in feet or meters).  Looking at the numbers below may offer additional insight as to why the ACCC conductor has been selected and deployed at over 210 projects, worldwide.  Improved Efficiency, Higher Capacity, and Proven Reliability.

In This Issue
Live Line Upgrades with ACCC
210+ ACCC Projects Completed
Jim Lehan NV Energy Shares His Experience Using ACCC Conductor please watch this video
The Economics of Efficiency
New Engineering Software
New Engineering Manual
CTC at Your Service

 

New CCP Software

Makes ACCC Conductor
Selection Easy
 
 

 

Responding to an ever-increasing demand to help select the most appropriate size of the highest performing ACCC conductor available, CTC Global has developed a new software program, CCP.

 

The program is available at no charge to utility planners, transmission engineers and others involved in conductor selection, project engineering and project economics. Using the design parameters associated with your specific project, CCP can calculate and compare ampacity, sag / tension, line losses, and the economics associated with the reduction in thermal sag and line losses the ACCC conductor offers compared to any other conductor of the same diameter and weight.

 

To receive a free copy of CCP, or to request help with your project, please visit CTC Global's website for more information.

  

CLICK HERE 

 

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ACCC Engineering Manual 

              

 

To help T&D planners, engineers, and technicians take full advantage of the ACCC conductor's attributes, CTC Global has published a 250 page Engineering Manual. Contact CTC Global today to request a copy.

 

CLICK HERE 

 

 

CTC Global at Your Service

 

CTC Global's staff consists of dozens of individuals whose varied skill sets help us deliver the highest quality products and services, worldwide.  In this issue, we'd like to acknowledge Anne McDowell, International Business Development Director at CTC Global. 

 

 

Anne first joined CTC in 2006 as CTC's Marketing Coordinator. Her product knowledge and communication skills moved her quickly from a supporting role into management. Anne now oversees a number of other CTC staff members that help CTC support its customers, stranding partners and suppliers, worldwide.

 

Anne lives in Southern California with her husband Ken and  their  beautiful baby Shia. CTC Global and our customers greatly appreciate her dedication and support. We're pretty sure her husband Ken feels the same way.

 
 
 INCREASED CAPACITY. IMPROVED EFFICIENCY. PROVEN RELIABILITY. ACCC 
 
*ACCC is a registered trademark of CTC Global Corporation
CTC Global - 2026 McGaw Ave. Irvine, CA 92614 USA +1 (949) 428-8500