Mitsubishi Electric Corp.'s Power Distribution Systems Center produced its milestone one millionth medium-voltage circuit breaker in Marugame, Kagawa Prefecture, Japan in March.
Medium-voltage circuit breakers protect electric facilities and power distribution networks in buildings, factories and other industrial facilities by cutting off irregular current in the case of accidents such as lightning strikes to power networks.
Going forward, Mitsubishi Electric will continue to contribute to the safety and stability of power systems by developing and commercializing electricity technology for advanced industrialization and environmental protection, including the reduced use of hazardous substances based on RoHS standards.
The PDSC facility was established as the Marugame Factory in 1979 to produce medium-voltage circuit breakers, such as vacuum breakers and gas circuit breakers. Over the years, it has produced circuit breakers featuring high reliability, compactness and minimized maintenance. The PDSC's cumulative shipments of circuit breakers units exceeded one million units in March 2014, the year marking the facility's 35th anniversary. The one millionth unit was a VF-8/13 model 7.2kV vacuum circuit breaker, Mitsubishi Electric's main circuit-breaker model. VF-8/13 shipments average more than 20,000 units per year and account for more than a 60% Japanese market share among models rated for voltages of 3.6/7.2kV and breaking currents of 8-12.5kA. The one million units have included 965,000 vacuum circuit breakers, 22,000 air- or magnet-circuit breakers and 13,000 gas circuit breakers.