Arrangement for the indication of overpressures due to fault arcs in air-insulated sealed or metal-clad switchgears

摘要

1. An arrangement for detecting pressureincreasing fault arcs in air-insulated switchgears having sealed or metal-clad areas (R1, R2, R3) by means of pressure-dependent switching devices that, together with excess-current-dependent switching devices, trigger through a relay circuit a power switch associated with the respective switchgear at the infeed point concerned, characterised in that at places outside the metal-clad areas (R1, R2, R3) that are accessible during operation at least one pneumatic pressure switch (DS) that responds only to an increase in pressure and has a specified, measurable cut-in pressure is connected, by way of separate non-return valves (RV1, RV2, RV3) acting to retard decreases in pressure, to electrically insulated pipe-lines opening into the spaces to be monitored.