Outdoor vacuum switch disconnector for railway applications
15 - 29 kV | FLa 15/97-1B series Driescher

Vacuum switching
* The trend is to use a vacuum
Basic research on switching in a vacuum began in
Germany during the Seventies. At this time low-oil
switches had become firmly established in medium
voltage networks, based on their reliable operation
over decades, and were accepted by users as reliable devices. In laboratory tests it proved that the
vacuum switches were superior by far to the conventionally applied switching principles.
All these requirements necessitate a switching unit
with electrical properties that preferably do not
change throughout its service life. The vacuum interrupter is hermetically sealed and fitted with the
purest of materials. For reliable switching the required vacuum remains intact throughout the entire service life. Also the contact resistance remains at very
low values and does not increase due to age because there is practically no oxidation process in a
vacuum.
Based on an patented insulation system developed
by us there is also no liquid or gaseous medium
required for the external insulation strength of the
vacuum interrupters.
The outdoor switch disconnector FLa 15/97-1B is
therefore also suitable for all applications and for
rated voltages of 15 kV to 29 kV.
Through the use of insulators with different creepage distances the switches are suitable for very different cases of application.