Development of arcing horn device for interrupting ground-fault current of 77 kV overhead lines

This paper describes an arcing horn device for interrupting the ground-fault current of 77-kV overhead lines. The main characteristics of the device are as follows. The arcing horn device interrupted the ground-fault current 445A within a half cycle without replacement ten times. The arcing horn device did not interrupt short-circuit current. However, even when a short-circuit current of 10 kA flowed through the interruption portion, the device did not explode and damage any surrounding apparatus, such as insulators and conductors. The arcing horn device flashovered perfectly in the interruption portion when a lightning impulse voltage of 1400 kV was imposed under dry, water-sprayed and contaminated conditions. The arcing horn device was installed on a 77-kV overhead line belonging to the KANSAI Electric Power Co, Osaka, Japan, and was found to interrupt the ground-fault current.