The Siemens 5SL7450-8RC is a 4-pole miniature circuit breaker (MCB) rated for 415 V with a 10 kA breaking capacity and a D tripping characteristic at 50 A. The D-curve characteristic means it tolerates high inrush currents typical of motor, transformer, and lighting loads, tripping between 10x and 20x rated current for short-circuit protection. The 10 kA breaking capacity at 415 V is the maximum fault current it can safely interrupt — sized for standard commercial and light industrial distribution panels where prospective short-circuit current stays under that threshold.
The 4-pole format (3 phases + neutral) snaps onto standard DIN rail in the distribution board, occupying four modular-width spaces. Rated for 415 V line-to-line, it is the correct fit for three-phase 400 V TN and TT systems common across European and IEC-based installations.