What the ratings mean for your panel
The B-curve (tripping between 3 and 5 times rated current) is the standard choice for resistive and general-purpose loads — lighting circuits, control transformers, small power supplies. If your line has motor inrush or high inductive loads, a C-curve sibling would be the better fit, but for most panel auxiliaries this B-curve holds fine. The 10 kA breaking capacity at 400 V AC (per EN 60898) means it can safely interrupt a fault current up to 10,000 amps without welding contacts or cascading failure upstream. That's adequate for most secondary distribution panels fed by a transformer of 630 kVA or less. For single-phase operation it's rated at 230 V and 440 V AC, and DC operation up to 72 V. Temperature derating matters in a sealed cabinet: the breaker is rated for ambient up to 75 °C, but humidity must be kept under 35% above 70 °C. In a hot, damp railcar junction box, that derating curve is what keeps the trip threshold predictable. Vibration resistance is specified per IEC 60068-2-6 at ±1 mm from 5 to 25 Hz and 50 m/s² from 25 to 150 Hz — that covers the rail vehicle body and bogie-mounted equipment spectrum. If your application sees higher shock or sustained vibration (e.g., off-road vehicles), this breaker is still a candidate but verify against your specific vibration profile.