Power Line Africa has completed the installation of the newly introduced ULS (Ultra Low Sag) ACCC conductor in Congo, Africa. The new double-circuit 120-kV line crossed Lake Nzilo in the Democratic Republic of the Congo to provide power to the Mumu mine. The mine is located near the town of Kolwezi in the Katanga Province, an important copper, cobalt and uranium mining center.
Power Line Africa selected CTC Global’s new ULS ACCC conductor for its high-strength, light-weight, high-capacity and excellent self-damping characteristics. The ACCC ULS 451-kcmil (229-mm2) Monte Carlo-size conductors span 4,491 ft (1.369 km) over the lake between newly erected 354-ft (108-m)-tall lattice structures.
The tensile strength of conventional ACSR steel core is about 210 ksi (1,448 MPa), and the tensile strength of the standard ACCC conductor core is 313 ksi (2,158 MPa). The new ULS ACCC core offers a tensile strength of 375 ksi (2,586 MPa), which substantially raises the performance bar over any other conductor on the market today. The weight of both the standard ACCC core and the ULS ACCC core are about 70% lighter than steel, each of which also offers a coefficient of thermal expansion about one-tenth that of steel.
To install the ACCC ULS conductor, the crew began by pulling a floating rope across the lake. The rope was then attached to a woven steel pilot line, which was lifted into position and used to pull in the new ACCC conductor. After the conductor was installed, in addition to aviation markers mounted on the overhead ground wire, several 150-lb (68-kg) induction lights were placed on the lower conductor phase wire for
additional aircraft safety.
While several ACCC conductor installations have already been completed in South Africa (most of which were energized live-line reconductoring projects for Johannesburg Power), this particular project was the second long-span project undertaken in Africa. Earlier this year, ACCC conductor was used to repair a long-span section of a 500-kV DC line in Mozambique that was knocked out of service when flood water downed a structure.
For more information, visit www.ctcglobal.com