Siemens has installed and commissioned what it believes is the world’s first 8DAB 24, the ‘blue GIS’ medium-voltage system, in the Alpine town of Davos, for its customer EWD Elektrizitätswerk Davos AG. The 24kV circuit-breaker switchgear, which uses Clean Air as insulating gas instead of sulphur hexafluoride (SF6), is deployed in the Dorf substation in Davos.
Siemens fluor-gas-free blue GIS-portfolio, its first SF6-free solution, was launched ahead of EU regulations around seven years ago. It has since installed many more, this being the latest addition. “SF6 was never ideal for the environment,” said Andy Kollegger, CEO of EWD. “There was no doubt in our minds: if there is an alternative on the market that has the same functionality but without this disadvantage, we will switch to it.”
EWD Elektrizitätswerk Davos AG operates three substations, 168 transformer stations, 154 km of medium-voltage grid and 300 km of low-voltage grid in the Davos grid area.
The Clean Air used as an insulating medium in the blue GIS portfolio consists of natural components of ambient air, making it climate-friendly, extremely stable, non-toxic, non-flammable, and suitable for all operating temperatures. In addition, the blue GIS switchgear is equipped with smart sensors and standardised interfaces for its comprehensive IoT suite Electrification X.
