New Method of Leak Rate Measurement in SF₆ Free Medium Voltage Switchgear Using Helium and Ambient Air

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.