252kV. 4000A SF6 Circuit Breaker High Voltage Sealed High Voltage Circuit Breaker

Summary

Sulfur hexafluoride circuit breakers may be used as self-contained apparatus in outdoor air-insulated substations or may be incorporated into gas-insulated switchgear which allows compact installations at high voltages.

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.

SF6 gas is electronegative and has a strong tendency to absorb free electrons. The contacts of the breaker are opened in a high-pressure flow of sulfur hexafluoride 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.

Baikong electric was born and developed well Sichuan Baikong Electrical Technology Co., Ltd is a complete set of high and low voltage power distribution equipment automation equipment, set production, research and development and sales Import and export services and other integrated enterprises, the company is headquartered in Pengzhou Industrial Park, Chengdu City.The company's main products are box-type substation Medium and high voltage power transmission and distribution equipment, low voltage power distribution equipment, fire electrical equipment, intelligent industrial electrical equipment, new energy and energy storage electrical equipment, metering and protection power distribution equipment, high and low voltage complete switchgear, high voltage ring network cabinet, cable branch box,SF6 inflatable cabinet, etc.