What the ratings mean for fit
The 5SL4425-6 is a 4-pole SENTRON miniature circuit breaker rated 25 A at 30 °C with a B tripping characteristic, meaning it trips at 3–5× rated current — the standard choice for residential and light-commercial lighting and socket-outlet circuits where inrush is low. The 10 kA breaking capacity per EN 60898 (also rated 10 kA per IEC 60947-2) tells you it safely interrupts fault currents up to that level without upstream cascading — sufficient for most building-distribution panels fed by a transformer of typical impedance. The 400 V AC rated voltage (440 V max multi-phase) covers three-phase 400/415 V networks common in European and Asian installations.
Derating and ambient conditions
The 25 A rating holds at 30 °C ambient; at 40 °C it derates to 23.68 A, at 45 °C to 23 A, and at 55 °C to 21.54 A. If the panel runs warm — say, a packed enclosure near a boiler or drive cabinet — size the upstream protection for the derated value at your actual ambient, not the 30 °C headline. The breaker is rated for ambient temperatures from -40 °C to +75 °C, with up to 95% humidity at 55 °C, so it handles outdoor enclosures in cold climates and humid infrastructure rooms without condensation issues.
Panel integration and mounting
Snap-on DIN-rail mounting in any position. The 4-pole body occupies 4 modular width units (72 mm wide, 90 mm tall, 76 mm deep with 70 mm installation depth). IP20 with connected conductors — standard for enclosed distribution boards; not rated for washdown or outdoor exposure without a weatherproof enclosure. The sealable feature allows the installer to lock the toggle position after commissioning, preventing unauthorized reset or isolation on live circuits.