Abstract
The current medium voltage Gas Insulated Switchgears (GIS) predominantly use Sulphur Hexafluoride (SF6) as insulation medium. The leakage tests performed on GIS use either SF6 or Helium medium to ensure gas tightness. However, SF6 has been strictly regulated for the last years due to the high global warming potential effect on the planet. As a response, new technologies are emerging using air as insulation medium. The present work establishes a basic comparison of the leakage rate in a medium voltage GIS using two different leak detection methods: Helium leak detector and Residual Gas Analyser (RGA). Both methods use Helium and additionally RGA using air as tracer gas.