Currently, the application of arresters is drawing attention for the p
revention of lightning faults on transmission lines. The line arrester
s presently in use are of the long-rod type, which are installed in pa
rallel with insulators. We have developed a suspension-type line arres
ter employing advanced technologies such as improved ZnO elements and
their incorporation in an insulator shed, which can be used as a repla
cement for conventional insulators without a series gap. The high perf
ormance and reliability of the suspension-type arrester have been conf
irmed by laboratory and outdoor tests. A field test on a 66-kV service
line was commenced in 1991.