After long years of service the majority operating functions of medium voltage switchgear have been without any serious problems. A dominant economic value is presented by switchgear, or breaker respectively, and overall activities performed in order to extend its service life lead toward significant saving in investments. By Retrofit of the existing low-oil circuit breaker, HG type, produced by Energoinvest, it is realized vacuum circuit breaker HGV type. The reconstruction comprises installation of vacuum chambers into the existing low-oil circuit breaker cylinders, adaptation of stroke and speed, revision of the motor-spring operating mechanism and adequate tests. The modification process goes gradually: a couple of circuit breakers, already prepared by manufacturer, are to be replaced and reconstructed, and after that the rest, following the same procedure. These modified circuit breakers are cheaper than new ones and changing process does not require any additional steps in chambers. By this, a service life and reliable operation of the breaker are 30 years longer. |
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