The 5SY is the SENTRON miniature circuit breaker used across industrial distribution boards and control panels. We supply 1-pole to 4-pole devices across B, C and D tripping characteristics and the common 6 kA and 10 kA breaking capacities, in the 5SY4, 5SY6 and 5SY7 families, plus auxiliary and signal contacts.
Mainly breaking capacity and construction class. The 5SY4 covers standard 6 kA applications, while 5SY6 and 5SY7 step up in breaking capacity for boards with higher prospective fault current.
Not without checking. A C curve tolerates higher inrush but trips later on a fault, so cable protection and earth-fault disconnection times must be re-verified. Where the original was chosen for cable protection, replace like for like.