It carries a 25 kA Icu breaking capacity at 380/415 V AC (50/60 Hz) per IEC 60947-2, and 20 kA Icu at 440 V. The frame is fixed-mount, backplate style, with front-front connections (both line and load terminate on the front face). The 140 mm width and 161 mm height fit standard ComPacT panel cutouts. This is a basic frame — no trip unit included. You order the C25B4 as the chassis and separately select the appropriate Micrologic trip unit (electronic) or TM trip (thermal-magnetic) for the protection curve your load needs. The 250 A frame rating is the maximum continuous current the frame can carry; the trip unit sets the actual protection threshold.
The C25B4 carries dual certification: EN/IEC 60947-2 and UL 60947-4-1. That's a 100% Ics/Icu ratio at 415 V, which is good for selectivity studies and avoids nuisance replacement after a fault. That covers distribution panels fed from a transformer secondary, not just final subcircuits. The frame is isolation-suitable per EN/IEC 60947-2 — you can use it as a visible-break disconnect for safe maintenance if the trip unit and handle position indicate open contacts. Class II insulation on the front face means no earth connection needed on the operator interface.
Mechanical endurance is 20,000 cycles; electrical endurance varies with voltage and current, reaching 20,000 cycles at 440 V at half rated current.