New technologies, standards and maintenance methods in spacer cable systems

Overhead distribution lines with bare conductors for medium and low voltage circuits are being substituted due to their high failure rate and low security level, not attending the customer needs. More and more customers ask for better services and lower costs. These type of systems are greatly influenced by external causes such as lightning, rain, trees collision and vandalism. In Brazil based on the USA experience, the aerial spacer cable system has been shown as the best system to improve its reliability. The low maintenance cost, easy operation, high security level and the attractive cost-benefit have justified its use, mainly in urban areas by CEMIG, a Brazilian electric utility. This paper describes the line design, equipment, standards and also, the maintenance methods in live-line and field experiences of the spacer cable system.