Biblioteca Central de la Universidad Nacional del Santa

ABSTRACT Around a 30% of all the world-wide sources of primary energy they are used to generate energy electrical, and almost all she is transmitted and distributed by means of systems of alternating current voltage of 50 Hertz or 60 Hertz. Nowadays, it is more important than ever to design and operate electrical systems that not only will have the maximum practicable efficiency; they also will have the highest degree of security and reliability. This note tries to deliver the elements to consider, in the design, various improvements in the reliability of electric systems. In the electrical systems the fact of, for example, not to have electricity at unexpected moments, brings serious productive consequences. A minute without electricity will cause: the loss of the data stored in a computer; the arrest of an engine, and therefore of a productive chain; that a medical operation is interrupted or altered; that is to say, in electrical systems it is necessary to tend to have the maximum possible reliability due to the fact that the consequences are extraordinarily relevant. In the city of Huaraz, the electric service provided by the concessionaire of electrical distribution HIDRANDINA S.A. denominated business unit Huaraz. Account with a commercial area, operations and maintenance. Their electricity grids in the city of Huaraz have 20 years. Which is why, in the district of restoration is had 7 064 supplies in BT system 380/220V in which the concessionaire HIDRANDINA S.A. report every day an average of 2 failures of interruption of electric service by external contingencies (strong winds and vehicular traffic of heavy load), destemplado and ruptures of rush. This makes it difficult to have a good reliability of electricity supply in BT in small customers.