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SafeRing Gas-insulated Ring Main Unit

Medium voltage (MV) SF6-insulated ring main unit for IEC secondary distribution applications up to 40.5 kV, 630A

SafeRing is a ring main unit (RMU) for the secondary distribution network.  It is available in 18 different configurations suitable for most switching applications within the range from 6 to 40.5 kV. The standardized RMU configurations, which are mostly required within a distribution network, can be extensible upon request.

SafeRing is a completely sealed system with a stainless steel tank containing all live parts and switching functions. A sealed steel tank with constant atmospheric conditions ensures a high level of reliability as well as personnel safety and a virtually maintenance-free system. 

Product scope

  • 12-24 kV, 630A
  • 36-40.5 kV, 630A 


  • Completely sealed system
  • Safe and reliable operation
  • Smart grid enabled
  • Compact design with small footprint and low physical weight
  • Most typical variants: RMU with standard variants up to 5 modules (12-24kV) or 4 modules (36kV)
  • Harmonized for higher flexibility: Select SafePlus switchgear for more options


  • Minimal maintenance
  • No live parts exposed
  • One full range up to 40.5kV
  • Module width: 325mm for 12-24kV, 420mm for 36kV
  • Optional integrated remote control and monitoring unit
  • Optional arc suppressor: No gases released even in arc fault cases 
  • Type tested according to all relevant IEC standards