The Siemens 5SU1354-7VK25 is a 2-pole (1P+N) SENTRON RCBO — a combined residual current device and miniature circuit breaker in one 36 mm wide, 2-module unit. Rated at 25 A with a 30 mA Type A residual current trip and a C-curve overcurrent characteristic, it handles mixed resistive and moderate inductive loads like small motor circuits, lighting, and socket outlets in commercial or industrial sub-distribution boards. The 10 kA breaking capacity per EN 60898 covers most building-installation fault levels; the 20 kA rating per IEC 60947-2 gives headroom for industrial panel applications where higher prospective short-circuit currents are possible.
What the ratings mean for fit
The 30 mA Type A residual current detects sinusoidal AC fault currents plus pulsed DC components — the standard for circuits with single-phase rectified loads like switched-mode power supplies, LED drivers, or variable-speed drives on the line side. The C-curve (5–10× In magnetic trip) means it tolerates inrush without nuisance tripping, suited for motorized loads and capacitor banks. The 10 kA (EN 60898) / 20 kA (IEC 60947-2) dual rating is the key differentiator: the lower figure applies when the RCBO is used as a household-type MCB/RCD per building standards; the higher figure applies when it's specified as a circuit breaker per the industrial standard, giving the panel designer a single part that qualifies for both regimes.
Deployment context
Mounts on DIN rail in any position — the 36 mm width (2 modular units) fits standard enclosure cutouts. IP20 rated when installed in a distribution board with connected conductors, so it's strictly for indoor, dry-location panels. The super resistant K design indicates enhanced resistance to environmental stress — temperature range from -40 °C to 75 °C and 95% humidity tolerance — making it suitable for unheated enclosures or outdoor-rated cabinets where condensation cycling occurs.
Compliance and documentation
Halogen-free and silicon-free construction — relevant for clean-room or high-reliability environments where outgassing or silicone contamination is a concern. The part carries IEC 60898 and IEC 60947-2 ratings, and the manufacturer provides CE declaration and RoHS/REACH documentation on request. Overvoltage category III and pollution degree 2 cover fixed-installation mains distribution.