The MGN61806 is a Schneider Electric Multi9 C60H-DC miniature circuit breaker — a single-pole, thermal-magnetic breaker rated 25 A at 50 °C, curve B, built for DC networks. The key spec for a buyer: at 110 V DC it breaks 20 kA Icu per EN/IEC 60947-2, at 220 V DC it breaks 10 kA, and at 250 V DC it still holds 6 kA. The curve-B magnetic trip fires at 5.5 x In ±20 % DC — so for a 25 A breaker, the instantaneous trip point lands between 110 A and 165 A DC. That's a tight window compared to a C curve, which means it clears low-impedance faults faster. Use it on resistive or lightly inductive DC loads where you want nuisance-tripping kept low but still need fast short-circuit clearance.
Where this breaker fits in a panel
Clip-on DIN-rail mount, 18 mm per pole. Strip length is 14 mm; torque to 2.5 N·m. IP20 on the terminals, IP40 inside the modular enclosure. It's padlockable and has a clear ON/OFF indicator plus a contact-position flag, so a technician can verify isolation visually before reaching in. Pollution degree 3 and tropicalisation (2, per IEC 60068-2) mean it handles dusty, humid environments up to 95 % RH at 55 °C without derating.