Statistics, design- and technological characteristics of main transformers of NPS units were compiled and ana-lyzed. In article the basic typical and probable scenarios of preemergency and emergency refusals of main transform-ers of NPS units TNTS-1250000/330 are investigated. . Reasons of unit transformer failures resulting in forced outage of the units were found. On the basis of the analysis of refusals methods of service of power transformers after them the normalized operation term are offered. Breakdown susceptibility researches have allowed to define the cores "risk zones" equipment, to reveal interpretations of various defects and to offer some kontrol-diagnostic management methods service life of the transformer equipment of blocks of the atomic power station of Ukraine
Keywords: unit transformers, bushings, shunt reactors, coupling autotransformers, breakdown and deteriora-tion of insulation, cooling system, reliability, safety.
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