The Siemens 5SJ4102-7HG41 is a SENTRON miniature circuit breaker — one pole, C-curve trip, rated to clear faults at 10 kA per EN 60898 and 15 kA per IEC 60947-2. That C characteristic means it holds through mild inrush (motors, transformers, lighting ballasts) and trips fast on a dead short. It's built for 400 V AC circuits and can handle 60 V DC on the same pole.
The 18 mm width (one modular unit) snaps onto standard DIN rail; depth is 70 mm, which fits flush in most enclosures. IP20 with conductors connected, IP40 in the handle area — fine for a dry panel, not for washdown zones.
Where it goes and what it handles
Vibration resistance at 50 m/s² (25–150 Hz) and 60 m/s² (35 Hz, 4 sec) means it stays latched on a machine skid or near a conveyor drive.