Reliability of conception and operation for SF6-insulated MV equipment

Among the different aspects of electrical switchgear, dependability is certainly the characteristic for which the users have the highest expectations of improvement. The aim of this contribution is, after a short reminder on dependability, to show how a manufacturer can fulfil this need of improvement. The differences between air insulated and SF₆ insulated metal-enclosed switchgear are then evaluated to show how the guidelines of dependability influence the development process: ISO series 9001, calculations, qualification tests, ergonomics, diagnostics, etc