A circuit breaker is a device used to complete, maintain, and interrupt currents flowing in a circuit under normal or faulted conditions. A vacuum circuit breaker utilizes a vacuum to extinguish arcing when the circuit breaker is opened and to act as a dielectric to insulate the contacts after the arc is interrupted. One type of circuit breaker is called a recloser. A vacuum recloser is designed to interrupt and reclose an AC current circuit automatically, and can be designed to cycle a set number of times before it must be reset manually.
 Figure 1. Vacuum circuit breaker, inside |
 Figure 2. Vacuum circuit breaker, outside |
