what is vaccum circuit breaker mechanism
Vacuum circuit breakers have minimal arcing (as there is nothing to ionize other than the contact material), so the arc quenches when it is stretched a very small amount (less than 2â3 mm (0.079â0.118 in)). Vacuum circuit breakers are frequently used in modern medium-voltage switchgear to 38,000 volts. Also indicates the status of the circuit breaker (On or Off/tripped). 2  Most breakers are designed so they can still trip even if the lever is held or locked in the on position. 3  This is sometimes referred to as free trip or positive trip operation. 4  Actuator mechanism-forces the contacts together or apart.