Technical Parameters General Product Type: Miniature Circuit Breaker (MCB) Model: S203M‑D25 Series: System pro M compact S200M Number of Poles: 3 (three‑pole) Trip Curve / Characteristic: Type D (thermal‑magnetic) Mounting: DIN rail (TH35) Actuator: Toggle switch with ON/OFF indication Terminal Type: Screw terminals Applicable Standards: IEC/EN 60898‑1, IEC/EN 60947‑2 Pollution Degree: 3 Overvoltage Category: III Current Limiting Class: 3 Installation Size: Standard modular width for S200M series Electrical Ratings Rated Current (In): 25 A Rated Operational Voltage: AC: up to 400 V AC (IEC 60947‑2): up to 440 V Rated Insulation Voltage (Ui): 440 V Rated Impulse Withstand Voltage (Uimp): 4 kV Rated Short‑Circuit Breaking Capacity: 10 kA (IEC / EN 60898 at 230 V AC) 15 kA (IEC 60947‑2 at 400 V AC) Rated Ultimate Short‑Circuit Breaking Capacity (Icu): Up to 25 kA at 230 V AC Rated Service Short‑Circuit Breaking Capacity (Ics): Typical portion of Icu Frequency Rating: 50/60 Hz Connection & Wiring Connectable Conductor Cross‑Section: Solid: 0.75 – 35 mm² Flexible with Ferrule: 0.75 – 25 mm² Busbar Connection: up to 10 mm × 10 mm Tightening Torque: approx. 2.8 N·m Mechanical & Endurance Mechanical Endurance: ~20,000 cycles Electrical Endurance: ~20,000 switching cycles Power Loss: ~9.3 W total (approx. 3.1 W per pole) Environmental Operating Ambient Temperature: approx. –25 °C to +55 °C Storage Temperature: approx. –40 °C to +70 °C Degree of Protection: Terminals: IP20 With enclosure cover (panel mounted): typical IP40 Physical Dimensions Width: ~52.5 mm Height: ~88 mm Depth / Recess Depth: ~69 mm Weight: approx. ~0.375 kg Features & Applications Thermal‑magnetic protection for circuits with moderate to high inrush currents Suitable for distribution boards, switchboards, and motor circuits Protection against overload and short‑circuit faults in residential, commercial, and industrial environments Can be fitted with auxiliary contacts or accessories to extend functionality