Externally gapped line arresters a critical design review

Good system reliability is a fundamental requirement for today´s power systems. In many parts of the world, lightning is one of the top five reasons for transmission line outages. Until this type of outage is eliminated or minimized, the power systems will not be able to meet their full potential. Shield wires over transmission lines can offer up to an 80% reduction in outages due to lightning; however, with the application of arresters a more lightning proof transmission line can be achieved. The externally gapped line arrester (EGLA) remains un-energized throughout its life and inherently is not subject to system voltage induced failures such as dielectric degradation or temporary overvoltage. This paper the design, application and benefits of the EGLA.