Design for reliability-methodology and cost benefits in design and manufacture

The importance of quality and reliability in all kinds of switchgear has increased. Quality and reliability have to be an integrated part of development activities. Reliability starts with the right design, followed by the choice of suitable material, using the relevant testing procedures and the appropriate manufacturing techniques, all accompanied by stringent quality control. So future oriented methods of development, e.g. by using the very latest procedures for computer aided design, optimisation of parts and components, dynamic calculations of arc extinction and drive behaviour accompanied by quality checks are well known methods to achieve the customer´s expectations. The author discusses the situation of circuit breaker reliability in relation to the CIGRE Second International Enquiry into Reliability of High Voltage Circuit Breakers. The author also discusses reliability improvement, after sales service, and MTBF as the most significant indicator of reliability. The influence of reliability on running costs is also mentioned