What it is and what it does
The Siemens 5SY4325-7CC is a SENTRON miniature circuit breaker (MCB) with a C tripping characteristic, designed to protect branch circuits against overloads and short circuits in commercial and industrial panels. Its 3-pole construction switches all three phases simultaneously, and the 10 kA breaking capacity per EN 60898 means it can safely interrupt fault currents up to that level without upstream cascading — critical for selectivity coordination in a distribution board.
Ratings and what they mean for fit
Rated 25 A at 35 °C ambient, it derates to 23.5 A at 40 °C, 22.72 A at 45 °C, 21.9 A at 50 °C, and 21.05 A at 55 °C — the thermal curve matters when the breaker sits in a warm enclosure alongside other heat sources. Pollution degree 3 and overvoltage category III suit it for fixed installations inside an industrial panel where conductive dust or condensation may be present. The IP20 rating with connected conductors means the front face is finger-safe but the terminals require enclosure protection.
Panel integration and mounting
Occupies 3 modular width units (54 mm) on DIN rail with quick assembly. Installation depth 70 mm, overall depth 76 mm. Sealable.