The new generation of circuit breakers, such as the ADVAC breaker with a torroidal spring, were

designed specifically for use with vacuum technology.

Each generation reflects the best technology available at the

time of their introduction, building on the strengths of previous designs, yet adding new innovations,

marking true turning points.

Although it is well established that vacuum interrupters are

capable of more than 10,000 operations, conventional stored

energy circuit breakers seldom operate beyond 10,000 operations without teardown,

re-lubrication, and/or replacement of parts.

More than 100 parts are required to perform spring charging, closing, anti-pumping and tripping

functions.

Conventional stored energy breakers also place limitations on the types of control voltages allowed. 

Vacuum interrupters were mounted in

open moldings, making them susceptible to dust, moisture, and corrosive atmospheres.

The AMVAC is truly the next generation in medium voltage vacuum technology. 

With the AMVAC, ABB is the first to combine

the unique requirements of vacuum interrupter technology to a

stored energy mechanism designed to exploit these capabilities.

Using a flux-shifting device with integral permanent magnets,

the AMVAC mechanism has just seven moving parts. Having

only an open/close actuator, an electronic controller, and capacitors for energy storage, the AMVAC

circuit breaker mechanism

is capable of 50,000 to 100,000 operations. Vacuum interrupters are embedded in a proprietary epoxy

material, achieving

excellent dielectric and thermal capabilities. Eliminating mechanism operated cell switches, the AMVAC

breaker packages all auxiliary control contacts on the circuit breaker. These are just a

few of the features that mark a departure from the conventional

stored energy breaker and introduce new capabilities and benefits for the modern power systems.