Electrical switching device

An electrical switching device defining a tank volume, the electrical switching device comprising:

• a longitudinal axis;
• a nominal contact arrangement with a first nominal contact and a mating second nominal contact;
• an arcing contact arrangement with a first arcing contact associated with the first nominal contact and a mating second arcing contact associated with the second nominal contact, the first arcing contact and the second arcing contact defining an arcing volume comprising an arc-quenching medium;
• and
• an exhaust system surrounding the arcing volume and comprising:
• a first exhaust opening connected fluidly to the tank volume;
• an exhaust channel extending from the arcing volume to the first exhaust opening, the exhaust channel being arranged for dissipating hot arc-quenching medium from the arcing volume through the first exhaust opening into the tank volume;
• a compression guide extending along the longitudinal axis;
• a piston arranged slideably in the compression guide;
• a side of the piston facing the arcing volume together with the compression guide defining a heating chamber fluidly connected to the arcing volume,
• a side of the piston opposed to the arcing volume together with the compression guide defining a compression chamber fluidly connected to the tank volume;
• and
• a plurality of inlet channels, each inlet channel fluidly connected to the compression chamber and extending to an inlet opening fluidly connected to the tank volume, the inlet channel and the exhaust channel being fluidly separated from each other, the inlet channel being oriented in a downward direction in a usage position of the electrical switching device, and, as viewed along the longitudinal axis in a direction opposed to the arcing region, the inlet opening being arranged after the first exhaust opening,
• wherein the plurality of inlet channels are distributed circumferentially with respect to the longitudinal axis, symmetrically with respect to a longitudinal symmetry plane the plurality of inlet channels having a corresponding plurality of inlet openings, and
• wherein the inlet openings are fluidly connected to a refill valve designed to allow passage of arc-quenching medium from the tank volume to the compression chamber and an overpressure valve designed to allow passage of arc-quenching medium from the compression chamber to the tank volume.