DC-rated miniature circuit breaker for 125 V circuits
The Siemens SENTRON 5SL5102-7CC is a 1-pole miniature circuit breaker rated for 125 V DC with a 10 kA breaking capacity and a C tripping characteristic. It occupies a single 18 mm modular width on a DIN rail, making it a direct fit for standard residential and infrastructure panels where DC branch circuit protection is needed — think solar combiner boxes, DC distribution in telecom shelters, or control power feeds.
What the ratings mean for fit
The C characteristic means the magnetic trip fires at 5 to 10 times rated current — right for moderate inrush loads like small DC motors, contactor coils, or capacitive filter banks. The 125 V DC rating covers the common 110 V DC nominal bus; the 72 V DC maximum operating voltage is the ceiling for the internal arc-quenching design on DC, so don't push it above that. The 10 kA breaking capacity is the maximum prospective fault current it can safely interrupt — adequate for most secondary distribution panels but check your available fault current at the point of installation.
Panel integration and environment
Snaps onto a 35 mm DIN rail, 18 mm wide (one modular unit), 76 mm deep. IP20 with connected conductors — protected against finger contact but not against moisture, so keep it inside a rated enclosure. Mounting position is unrestricted. The -40 to 75 °C ambient range covers unheated outdoor cabinets in cold climates and hot rooftop combiner boxes. Pollution degree 2 and overvoltage category III suit it for fixed installations downstream of the main distribution board.