Auto-resetting interrupter for use with 11 kV triggered spark gaps

Automatically resetting interrupters are necessary for interruption of the power-frequency currents following flashover of 11 kV triggered spark gaps, installed on overhead lines having no auto-reclosing facilities, in order to prevent sustained consumer outages. Development is described of a single-contact solenoid-operated interrupter with an oil-immersed armature designed to meet the requirement of fast operation and slow reset. Single-phase currents at voltages up to 3-4kV were interrupted successfully, with and without the triggered gap in series. (A triggered gap was found to have some interruption capability itself). The principle of interruption of current, at high voltage, by employing the same current in a solenoid is verified. High-pressure hydrogen generated by the arc is the chief arc-extinction agent. The internal pressure required to interrupt current at 6.35 kV is estimated to be several hundred kilotorr. Further development could result in an interrupter which meets the specification for application to the 11 kV system.