Many older installations of metal-clad switchgear are candidates for modernizing or upgrading. The interrupting duty may have grown past the interrupting capacity of the existing circuit breakers, maintenance costs may be getting out of hand, or circuit breaker parts may no longer be available.
Modernization may be accomplished by either of two methods, conversion of the existing equipment or replacement of the circuit breaker with a new, modern vacuum breaker. In some cases, modernization may involve conversion of the switchgear equipment and replacement of the circuit breaker. Modernization may also involve an increase in one or more ratings of the switchgear and/or circuit breaker.