EoW July 2014

News Technology

Aerial cable for sites with limitations

Kerite, a manufacturer of insulated medium voltage utility and industrial power cable, has announced a full line of preassembled aerial cable, for use between substation getaway riser cable and the circuit’s open-wire distribution portion, for express feeder circuits with site limitations, and for installation along space-constrained alleys and backyard boundaries and areas subject to tree-related storm damage. The company's twisted preassembled aerial cable has stood the test of time, with multiple examples of cable connecting a substation to exiting overhead lines lasting well above 50 years without any failures. Kerite’s preassembled aerial cable is composed of three shielded conductor cables banded together plus a messenger wire. The conductor, either aluminium or copper, is insulated with the time-proven Permashield semiconducting layer and discharge resistant EPR system, which is used by Kerite on cable designs up to 138kV.

▲ ▲ Preassembled aerial cable from Kerite

construction is cost prohibitive, use of preassembled aerial cable means that several express feeder cables can be safely installed below an open-wire pole-top circuit and then fan out to connect with the open-wire distribution system. Along alleys and backyard boundaries, where limited clearances between structures and line right-of-way are inadequate for open wire construction, preassembled aerial cable is a safe, effective alternative. Aerial cables also provide greater service reliability for areas where frequent tree and limb damage occurs during storm activity. Kerite – USA Website : www.kerite.com silane-grafted HFFRs. During burning, the material’s char is compact and protects the cable from accelerated burning. The new grade also offers the same chemical resistance as previous grades to such substances as oil, fuels, alkalines, acids and service fluids. Cogegum® GFR 380 incorporates a masterbatch that contains special additives to improve cross-linking action and aging. An anti-ultraviolet (UV) agent for enhanced weatherability is also part of the formulation. The material is rated for use up to 90°C (194°F) and can be adapted for certain applications up to 105°C (221°F). The material launch is the result of an extensive research and development programme by Solvay that not only focused on material formulation and compounding but also on plant-specific features to facilitate manufacturing. Cogegum® GFR 380 is commercially available throughout the world. Power, data and signal cables are among the key application areas. Solvay said the technology platform will be expanded to include other silane-grafted HFFR materials in the near future. Solvay Specialty Polymers – Italy Website : www.solvay.com

shield consists of a 5 mil cupro-nickel or copper tape and/or copper concentric wires. The single conductor cable may also have an overall jacket. The entire twisted assembly is bound to a Copperweld messenger with a copper or optional stainless steel strap that can also be covered with a PVC or PE jacket. medium-voltage cable designs in the Kerite product family, preassembled aerial cables is an option where many feeders come from a distribution substation, and underground construction is not a feasible option. For express feeder circuits with site limitations or where underground Solvay Specialty Polymers has expanded its family of Cogegum® cross-linkable, halogen-free flame retardant (HFFR) compounds for cable jacketing for the railway, shipboard, industrial, and oil and gas industries. The new polyolefin grade, Cogegum® GFR 380, delivers greater flexibility and superior flame resistance compared to competitive silane-grafted HFFR materials. The new grade represents a major breakthrough in the silane-grafted HFFR space, according to Luigi Dalpasso, senior vice president, head of cross-linkable compounds for Solvay Specialty Polymers. Cogegum® GFR 380 addresses the inherent limitations of silane-grafted HFFR materials which are typically stiff because of the lack of a plasticiser component. With a 38 Shore D hardness, the new grade is softer and more flexible than competitive silane-grafted HFFRs which typically exhibit a 45 to 50 Shore D hardness. This is particularly important in railway and shipboard applications where cable space is narrow and bending ability is a key advantage. Solvay claims that Cogegum® GFR 380 provides superior flame retardant properties compared to competitive One of several

The cable’s insulation shield is a free-stripping design and the metallic

Family expansion from Solvay

36

www.read-eurowire.com

July 2014