Safety by design: Solid insulated technologies challenge the use of SF6 in medium-voltage switchgear

Much information has been disseminated regarding the environmental impact and workplace safety of medium-voltage gas insulated switchgear (GIS) assemblies installed in industrial facilities. This paper will present some of the common myths and “technical documentation” available regarding circuit breakers utilizing Sulfur Hexafluoride (SF6) gas interrupters and switchgear using this gas for insulation. Focus will be on regulatory, operational and total life-cycle costs associated with this technology and safety from the perspective of not just the electrical workplace but the impact of SF6 designs on the business and the impact on the planet. Although SF6 designs have been commercially available and have functioned reliably for the past 30 years, new available technologies have emerged that offer comparable footprints and superior performance without adding the business risk of containment, required safety data sheet documentation and end of life disposal challenges presented by legacy SF6 based designs. A total ownership cost analysis will be presented including estimated purchase cost, operation and maintenance cost, regulatory compliance cost and dismantling-recycling cost of SF6 versus the next generation “safety by design” switchgear offering.