vacuum circuit breaker in the arc extinguishing and insulation medium according to the specific type of different, mainly divided into the following cases:
1. Main insulation medium types
- Vacuum
The core feature of the vacuum circuit breaker is that the inside of its interrupter chamber is a high vacuum state (usually up to 10-³-10-⁴ Torr), which utilizes the high insulating properties of the vacuum to prevent the damage of the arc to the contacts and insulating materials. In this state, the gas molecules are thin, and the collision free action is extremely weak, thus realizing efficient arc extinguishing.
- SF₆ gas
Some vacuum circuit breakers (e.g., high-voltage circuit breakers) are filled with sulfur hexafluoride (SF₆) gas as an insulating and arc-extinguishing medium.1 SF₆ has excellent insulating properties and arc-extinguishing capabilities, can withstand high voltages and high currents, and is a commonly used high-voltage circuit-breaker medium in the power system.
2.other related media
- Inert gas : In some specially designed circuit breakers, nitrogen, argon and other inert gases may be filled to enhance the insulating properties, but SF₆ is still the mainstream choice because of better overall performance.
- Other gases : Oxygen, carbon dioxide and other gases may be used in rare cases, but attention should be paid to their oxidizing properties that may cause corrosion to the equipment.
Supplementary Notes
- Gas pressure: For gas-filled circuit breakers (e.g. SF₆ circuit breakers), the gas pressure should be controlled within a certain range (e.g. 10-40 atm) to ensure insulation and arc extinguishing effect.
- Vacuum bubble structure: Vacuum bubble is not completely vacuum, but to maintain a very low pressure state, usually through the sealing structure to prevent gas leakage.
the insulation and arc extinguishing medium of vacuum circuit breaker is mainly vacuum, some models will be supplemented with SF₆ gas, the specific selection depends on the voltage level, current capacity and other parameters.
For more information of 12~40.5kV vacuum circuit breaker ,pls feel free contact me by email (xdtz02@westpowerelectric.com).
