VCB means Vacuum Circuit Breaker it used in high voltage (HV) lines.
*It has this one mechanism in this mechanism spring is there it is connected with small electric motor for charging the spring but we can do manually charge also by this spring tension circuit closing or circuit open can be done. The circuit closing can be done by (CC closing coil) also. In VCB CT are used for measuring, controlling & protection purpose.
ACB means air circuit breaker it is used in low voltage (LV) lines
*It has also one mechanism it also work same. ACB is used for tripping purpose when power fail. It has (CC Closing coil) for closing the circuit. CT are used for measuring, controlling & protection purpose.