Suppression of noise in air-blast circuit breakers

Changes in air-blast-circuit-breaker design concepts, resulting from increased fault ratings together with an increasing public intolerance of noise nuisance, directed attention to the suppression of noise in air-blast circuit breakers. The problem was defined, and difficulties arising in the application of established measurement and assessment techniques to the short-duration infrequently occurring noise emitted by air-blast circuit breakers were resolved. Silencers were designed which reduced the noise from existing circuit breakers to acceptable levels, and sufficient experience was gained to ensure that future designs of air-blast circuit breakers will be quiet in operation.