Power switch unit e.g. vacuum switch for use in three-pole power switch to switch electrical current in e.g. medium-voltage application, has control volume connected with chamber such that same pressure prevails in volume as in chamber

摘要

The switch unit i.e. switching pole (1), has two contact elements electrical conductively in contact with an evacuated vacuum switching chamber (K). A control volume (5) is provided in a component i.e. displaceable contact element (3), extending-out from the switching chamber. The control volume has a longitudinally extending channel, and is in fluid connection with the chamber such that same pressure prevails in the volume as in the chamber. An electronic detection device detects a change of the pressure in the control volume and/or in an internal volume of a connector (SV). An independent claim is also included for a method for detecting a change in a switching chamber of a power switch unit.