The Siemens 5SY4163-7CV is a 1-pole miniature circuit breaker (MCB) with a C63 tripping characteristic and a rated ultimate breaking capacity (Icu) of 15 kA at 230/400 V AC. The C curve means it handles moderate inrush currents typical of motor and lighting loads, tripping between 5 and 10 times rated current for short-circuit faults. The 15 kA Icu tells you this breaker can safely interrupt fault currents up to that level without welding its contacts or damaging downstream equipment — a critical spec for panel coordination in high-fault installations.
The single-pole form factor snaps onto a standard DIN rail inside the enclosure. In a panel with multiple 5SY breakers, the 1-module width (roughly 18 mm per pole) keeps fill factor tight — plan for the same pitch as other Siemens 5SY units.