The Siemens SENTRON 5SL4250-8CC is a 2-pole miniature circuit breaker with a D tripping characteristic, rated 50 A at 400 V AC and a breaking capacity of 10 kA per EN 60898. Rated current derates with ambient temperature: 46.19 A at 40 °C, 44.17 A at 45 °C, 42.05 A at 50 °C, and 39.81 A at 55 °C. Mounting position is unrestricted — can be oriented vertically, horizontally, or flat against the rail.
Lifecycle and sourcing status
No official successor has been published. The part is a standard catalog item in the SENTRON portfolio, so lead times are typically consistent with Siemens' production schedules for this class.
Touch protection is integrated (finger-safe terminals).
Electrical ratings and coordination notes
Maximum operating voltage on multi-phase AC circuits is 440 V. Single-phase supply rated at 400 V AC. For DC circuits, the maximum rated voltage is 72 V — this is not a general-purpose DC breaker for higher-voltage battery banks or solar strings. The neutral conductor is not switched (2-pole design switches both phase conductors, no integral neutral pole). Suitable for 2-phase or single-phase 2-wire applications where both lines are protected. Suitability listed for residential buildings and infrastructure — standard distribution board installation. Not specifically rated for motor-starting duty beyond the D-curve's inrush tolerance; verify coordination with downstream contactors if used in a motor branch circuit.