What this MCB is and what it does
The Siemens 5SY7625-7 is a SENTRON miniature circuit breaker (MCB) with a 4-pole 3P+N design, rated 25 A at AC with a C tripping characteristic. It breaks fault currents up to 15 kA per EN 60898 and 25 kA per IEC 60947-2, so it handles both residential and industrial fault levels. The C-curve means it trips between 5 and 10 times rated current — suited for inductive loads like small motors or transformers where inrush is moderate.
Ratings that govern fit
The 25 A rating holds at 35 °C ambient; derate to 23.8 A at 40 °C, 23.18 A at 45 °C, 22.55 A at 50 °C, 21.88 A at 55 °C, and 21.2 A at 60 °C. If your panel runs warm, size the load to the derated figure, not the nameplate. The DC breaking capacity is 15 kA per IEC 60947-2 — useful if this breaker sees battery-backed or rectified supplies. Pollution degree 3 and overvoltage category III mean it's rated for industrial enclosures where conductive dust or condensation is possible. IP20 with connected conductors — standard for DIN-rail distribution boards; no washdown rating.
Mounting and integration
Snaps onto DIN rail via the quick assembly system; any mounting position is allowed. Occupies 4 modular width units (72 mm wide). Depth is 76 mm, installation depth 70 mm — verify gland-plate clearance if the enclosure is shallow. Combined terminals top and bottom accept the same conductor range; sealable for tamper-proofing.