BY MICHAEL SKELTON Kelvatek Background One of the most critical devices on any electricity network is the circuit breaker which can be described as the silent sentinel, standing guard over the network and only being called into action when a fault occurs. The circuit breaker needs to operate within its composite tripping time (relay trip

By Baldwin Bridger 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