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段剑波 《智能建筑电气技术》2006,5(2):0-63
自动转换开关电器(ATSE)已经成为低压开关电气一个重要的组成部分,按照ATSE标准,ATSE分为PC级和CB级两种级别。目前行业对二者的认识、理解、使用都存在较大的差异。本文从可靠性、使用、维护的角度,分析了现有市场两种级别的ATSE,结论是:用断路器组成的CB级ATSE,可靠性低于PC级ATSE。 相似文献
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Curtis T. Ewing Francis R. Faith James B. Romans Charles W. Siegmann Ralph J. Ouellette J. Thomas Hughes Homer W. Carhart 《Fire Technology》1995,31(3):195-211
We investigated the extinguishing properties of multipurpose dry chemicals using openregime cribs of two sizes. One measured 20.3 by 20.3 by 15.2 cm, and the other 50.8 by 50.8 by 38 cm. A crib fire, which has both flaming and smoldering contributions, is primarily extinguished when the burning surfaces are covered or smothered by a gas phase of the original multipurpose agent or a product of the agent's decomposition. The overall effectiveness of each dry chemical depends on its particle size, the degree of its decomposition and/or vaporization, and the openness of the crib. All particles of an agent below a unique limiting size completely decompose and/or vaporize in the crib fire and have the same extinguishing effectiveness. Particles above the limit have no measurable effectiveness. Scaling is considered on the basis of the minimum extinction weight per unit of exposed wood surface.Carhart is recently retired from the U.S. Navy Technology Center for Safety and Survivability at the Naval Research Laboratory in Washington, D.C. 相似文献
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