The C25S3D is a Schneider Electric ComPacT NSX250S DC basic frame — a three-pole DC molded-case circuit breaker rated 250 A at 40 °C with a 100 kA interrupting capacity at 750 V DC per IEC 60947-2. It ships without a trip unit, so you select and install the appropriate electronic or thermal-magnetic trip separately. The 10 ms maximum break time keeps the let-through energy low enough to protect downstream gear.
Fixed mounting on a backplate — no DIN-rail clip on this frame. The 105 mm width by 161 mm height by 86 mm depth footprint fits standard panel cutouts for the ComPacT NSX family. Front-front connections (both line and load) keep wiring accessible without reaching behind the panel. IP40 front face protection means it's fine inside a clean enclosure but not for washdown areas.
Rated impulse withstand voltage of 8 kV covers surge environments typical of overvoltage category III (fixed installation, distribution level). Mechanical durability is 10,000 cycles; electrical durability varies by load — 10,000 cycles at half rated current, 5,000 cycles at full rated current, across all voltage levels listed.