The Siemens SENTRON 5SQ2370-2YA25 is a 3-pole miniature circuit breaker (MCB) with a C tripping characteristic, rated 25 A at 400 V AC. Its 3 kA breaking capacity per EN 60898 suits it for branch-circuit protection in residential and light commercial distribution boards where fault currents stay modest. The C-curve means it trips between 5 and 10 times rated current — standard for motor and lighting loads that see moderate inrush.
Ratings and derating
Rated 25 A at 30 °C ambient, the breaker derates to 23.75 A at 40 °C, 22.5 A at 50 °C, and 21.25 A at 60 °C. If your panel runs hot — common in a crowded enclosure — size the load to the derated value, not the 30 °C number. Pollution degree 3 and overvoltage category III mean it's rated for industrial environments where conductive dust or transient surges are expected.
Mounting and integration
Occupies 3 modular width units (roughly 54 mm) on a standard DIN rail. Installation depth is 55 mm — shallower than the 70 mm of the 5SL-series siblings, which matters when panel depth is tight. IP20 finger-safe terminals; no neutral pole switching (3P only, no switched neutral).