The future of GIS Insulation: moving beyond SF6 | Marcel Heckel, PFISTERER

SF6 has more than 20,000 times the global warming potential of CO2, and EU F-gas regulation will prohibit it in new GIS systems within the next years. PFISTERER is now requalifying its GIS cable terminations for that post SF6 world.

Marcel Heckel, Head of R&D for cable accessories and components at PFISTERER, joins Chris Gerber for APC Media at CIGRE 2026 in Paris to explain what changes when the insulation gas changes.

This matters now because GIS manufacturers are moving to synthetic air and fluoronitrile mixtures, and every connected component, including the CONNEX cable termination, must prove dielectric performance, sealing and material compatibility all over again through testing and revised IEC standards.

Key topics covered:

• SF6 earned its place with outstanding dielectric and arcing performance, but its climate impact has forced a regulated phase out in the EU.
• PFISTERER does not build switchgear, it connects cables to it, and its CONNEX GIS termination must work in synthetic air and C4-FN mixtures.
• Lower intrinsic withstand means higher pressure or revised geometry, plus full revalidation of AC stress, partial discharge, lightning impulse and switching impulse behavior.
• Smaller molecules such as CO2 change leakage behavior and can permeate epoxy, which makes sealing design more demanding than it was with SF6.
• Qualification is all testing led, fed by CIGRE Working Group B1.88 and the ongoing IEC revision for GIS cable terminations, with growth ahead from renewables, offshore and subsea cables.