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- Q1228904 subject Q7296663.
- Q1228904 abstract "High-voltage circuit breakers have greatly changed since they were first introduced in the mid-1950s, and several interrupting principles have been developed that have contributed successively to a large reduction of the operating energy. These breakers are available for indoor or outdoor applications, the latter being in the form of breaker poles housed in ceramic insulators mounted on a structure.Current interruption in a high-voltage circuit breaker is obtained by separating two contacts in a medium, such as sulfur hexafluoride (SF6), having excellent dielectric and arc-quenching properties. After contact separation, current is carried through an arc and is interrupted when this arc is cooled by a gas blast of sufficient intensity.The sulfur hexaflouride gas (SF6) is an electronegative gas and has a strong tendency to absorb free electrons. The contacts of the breaker are opened in a high pressure flow of sulphur hexaflouride gas and an arc is struck between them. The gas captures the conducting free electrons in the arc to form relatively immobile negative ions. This loss of conducting electrons in the arc quickly builds up enough insulation strength to extinguish the arc.A gas blast applied to the arc must be able to cool it rapidly so that gas temperature between the contacts is reduced from 20,000 K to less than 2000 K in a few hundred microseconds, so that it is able to withstand the transient recovery voltage that is applied across the contacts after current interruption. Sulfur hexafluoride is generally used in present high-voltage circuit breakers at rated voltage higher than 52 kV.Into the 1980s, the pressure necessary to blast the arc was generated mostly by gas heating using arc energy. It is now possible to use low-energy spring-loaded mechanisms to drive high-voltage circuit breakers up to 800 kV.".
- Q1228904 thumbnail Circuit_Breaker_115_kV.jpg?width=300.
- Q1228904 wikiPageWikiLink Q102836.
- Q1228904 wikiPageWikiLink Q1091878.
- Q1228904 wikiPageWikiLink Q15141485.
- Q1228904 wikiPageWikiLink Q158276.
- Q1228904 wikiPageWikiLink Q171183.
- Q1228904 wikiPageWikiLink Q184996.
- Q1228904 wikiPageWikiLink Q211058.
- Q1228904 wikiPageWikiLink Q279055.
- Q1228904 wikiPageWikiLink Q44395.
- Q1228904 wikiPageWikiLink Q632404.
- Q1228904 wikiPageWikiLink Q7296663.
- Q1228904 wikiPageWikiLink Q779785.
- Q1228904 wikiPageWikiLink Q78974.
- Q1228904 comment "High-voltage circuit breakers have greatly changed since they were first introduced in the mid-1950s, and several interrupting principles have been developed that have contributed successively to a large reduction of the operating energy.".
- Q1228904 label "Sulfur hexafluoride circuit breaker".
- Q1228904 depiction Circuit_Breaker_115_kV.jpg.