The Siemens 5SL4301-8 is a 3-pole miniature circuit breaker from the SENTRON 5SL4 series, rated 1 A at 400 V AC with a D tripping characteristic. At 1 A, it protects a branch circuit drawing under 1 A continuous; the 10 kA breaking capacity per EN 60898 (and IEC 60947-2) means it can safely interrupt a fault up to that level without upstream damage. The 3-pole version (3P) switches all three phases simultaneously, so it fits three-phase sub-distribution or machine infeed panels.
Occupies 3 width units (54 mm wide). Terminal torque: 2.5 to 3 N·m. Mounting position is unrestricted; ambient range -25 to +55 °C. IP20 with conductors connected — fine for enclosed panels, not for wet areas.