Electronic systems protection via advanced surge protective devices

Abstract

Surge protective devices (SPDs) have evolved along with the electronic revolution to address the key concerns of the telecommunications industry. New technological advances in electronics, design and manufacturing have been used to enhance the next generation of SPDs. These advanced SPDs are physically smaller because of advancements in metal oxide varistor (MOV) technology and new fusing techniques. Studies have shown that the majority of SPD failures are due to temporary overvoltage (TOV), not large surge currents. This increases the need for a fusing system integral to the SPD, which can disconnect the system under low fault conditions. The size reduction allows improved integration into electrical distribution equipment, takes up less wall space and allows for more components inside the distribution panels such as breakers, meters or communications equipment which lowers the overall costs. Improved overall system coordination can be achieved by using a single source for the integrated distribution equipment and associated components. These new integrated SPD systems provide superior performance, longer life and lower installed costs. When applied using IEEE's recommended cascaded approach for facility-wide coordinated protection, the new integrated SPDs offer the best solution for protection of complex electronic systems. This paper looks at key issues regarding effective use of SPDs and new designs that provide improved safety, reliability and system integrity.