Siemens has developed a medium-voltage switchgear that doesn’t require sulphur hexafluoride (SF6) as the insulating gas. It is designated 8DAB 12 and uses clean air consisting only of the natural constituents of ambient air as the insulating gas.

The switchgear is a new addition to the company’s 8DA and 8DB product family and also works with the existing vacuum switching technology. A vacuum-interrupter unit handles switching and arc extinguishing, while clean air insulates the current-carrying conductors inside the housing of the metal-encapsulated gas-insulated switchgear (GIS).

This type-tested system is designed to switch high currents at the primary distribution level. It is single-pole encapsulated and is included in the Siemens blue GIS portfolio. The new blue GIS portfolio is Siemens’ answer to the market requirements of customers who want to use both the proven properties of GIS systems in their power grids as well as a non-chemical insulating medium. But switches and switchgear that use SF6 as the insulating, switching, and extinguishing gas remain in the company’s range.

With the addition of the 8DAB 12, we’re systematically expanding our portfolio of medium-voltage switchgear,” said Stephan May, CEO of the Siemens Medium Voltage and Systems Business Unit. “We’ll continue to offer our customers proven vacuum switching technology and single-pole switchgear encapsulation. They can now select the characteristics of the insulating gases used, depending on their requirements. The functionality and dimensions remain the same as the switchgear in our 8DA series.”