What are the key operational differences between a vacuum circuit breaker and an SF6 circuit breaker in terms of arc quenching medium and maintenance requirements?

Vacuum circuit breakers and SF6 (Sulfur Hexafluoride) circuit breakers are both used to interrupt fault currents, but they differ significantly in their arc-quenching medium and maintenance requirements. The arc-quenching medium is the substance used to extinguish the electric arc that forms when the breaker contacts separate during a fault. A vacuum circuit breaker uses a high vacuum (typically 10^-7 to 10^-5 Torr) as its arc-quenching medium. When the contacts separate, the arc is drawn into the vacuum interrupter, where the vacuum prevents ionization and rapidly extinguishes the arc. SF6 circuit breakers use SF6 gas as their arc-quenching medium. SF6 is an inert, non-toxic gas with excellent die....