EHV Switch Tests and Switching Surges

Tests were conducted on the Pennsylvania Electric Company (Penelec) EHV (extra-high-voltage) experimental line using an I-T-E Circuit Breaker Company outdoor air break switch for switching an EHV line and transformer. Data have been accumulated concerning magnitude of switching surges when switching was done with a conventional disconnecting switch, with a gas blast (device, and with and without surge voltage suppressing resistors. The investigation was part of a comprehensive program intended to provide the best means of designing and applying EHV switches with proper insulation co-ordination.