Development of Vacuum Interrupters with High Interrupting Capacity

Vacuum interrupters, in which axial magnetic field type electrodes and CuCr contact materials are ccnbined, show excellent performance from all points of view. By this combination of electrode and contact material, the arcing phenomenon is scmewhat different from that of existing combinations. We have investigated the arcing and dielectric phenanena in detail and have found the optimum conditions. As a result, the new vacuum interrupters were developed in which interrupting capabilities have been improved. The application range is fran 12 to 84 kV in rated voltage and up to 5OkA in interrupting current. This type of vacuum interrupter was utilized widely in general field applications.