Circuit Breaker

I presume you are talking about MV & HV breakers .

After decades of raging technologic war between SF6 and vacuum, positions are now stable, depending on the applications and voltage .

In a nutshell, vacuum techno is the majority at 12 KV and below , use is balanced in the 12 to 24 KV area, and SF6 takes the lead above to remain the only solution in EHV above 200 KV.

Beyond this, some users find SF6 better for small MV motor switching and capacitor switching applications .

This of course also depends on countries and specific habits.