EoW March 2009

Power cable manufacturing, materials & machinery

Rotating machines for the production of HV/EHV transmission lines

Cloth tapes for cables

Neptco’s Powerline ® cloth tapes used in power cables are designed to separate, shield, identify and insulate power cable components, thereby reducing the incidence of failure and extending the life of power cables. Neptco’s Aquablok ® water blocking tapes are designed to protect power, telecom and fibre optic cables from the damaging and corrosive effects of water penetration and migration. Aquablok ® tapes are available in a wide variety of constructions including woven, non-woven, single- and double-sided, formulated with either insulative or semi-conductive properties. Neptco has manufacturing and distribution locations strategically located to supply multinational wire and cable manufacturers and will now service the European market with a new distribution facility in Rotterdam, Netherlands for its Powerline ® Aquablok ® , Lightline ® , and Flexline ® products. Neptco – USA Fax : +1 401 722 6378

Drum twister line for Milliken laying-up ▲ ▲

Gauder Group has always been active in the development of equipment for the manufacture of power cables, from low and medium to high and extra high voltage. Setic–Gauder Group designs and manufactures bunchers and large double twist stranding lines, while Pourtier is highly experienced in laying-up drum twister and modern stranding machines for copper conductors as well as large armouring and screening lines. The manufacturing process starts with the production of the copper conductor. For large conductors, the Milliken construction is used. The purpose is to reduce the “skin effect” thus permitting a better distribution of current in the conductor. The conductor mainly consists of 4, 5, 6 or 7 segments. Each segment is made up of wires, stranded and shaped in a rigid stranding machine, separated from one another by tapes during laying-up process. The stranding of sector shaped conductor, pre-spiralled, for high voltage cable, requires care. For this purpose, Pourtier has designed a rigid stranding machine for large reel size making possible the production of long lengths without welding. Special care has been paid to tension control on each wire, with automatic correction between full bobbin and empty bobbin and possible adjustment from the control desk during machine run. Special rotating heads ensure the necessary high quality of compacting, shaping and pre-spiralling of the conductor. Furthermore, a new side-loading system has been designed, allowing bobbin preparation during machine run (idle time) thus reducing down time and increasing machine efficiency. High voltage cable conductor must be handled with great care to prevent any damage or even any mark on the surface, deformation, incorrect alignment or contamination by foreign matter. The drum twister machine designed by Pourtier integrates all parameters to fit with severe production requirement of high voltage power cable including smooth deviation angle for the segments as well as for the laid-up conductor (resulting in a longer take-up frame). Tension control on each segment is of utmost importance for laying-up of Milliken cable to ensure perfect geometry of the finished conductor. A correction system is used to automatically adjust the relative position of each segment before entering into the laying-up block: up to five sensors are constantly controlling the position of the five segments and giving feed-back to each rotating pay-off stand whose rotation speed is automatically adjusted. No pressure or forcing is exerted on the segment, which is of paramount importance for the final quality of the product. Before entering into the stranding block, several tapes are longitudinally applied between the segments. This method requires particular attention: special guiding and tension control for each tape has been developed to ensure a precise insertion of the tapes in between the segment without any damage to these tapes. When laid-up, the segments form a tight, close-fitting construction. The segments are then taped together with semi-conductive tapes. The line also includes all possible facility to ensure complete water tightness of the cable. Gauder Group – France Fax : +33 1 64 26 61 10 Email : sales.pourtier@gaudergroup.com Website : www.gaudergroup.com

Email : jgeorge@neptco.com Website : www.neptco.com

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EuroWire – March 2009