The Siemens 5SY7425-8 is a 4-pole miniature circuit breaker from the SENTRON series, with a D tripping characteristic rated at 25 A and 400 V AC. It delivers a breaking capacity of 15 kA per EN 60898 and 25 kA per IEC 60947-2 — the higher IEC figure gives you selectivity headroom for industrial panel coordination where fault currents can climb above 15 kA. The D-curve (10–20× In) is designed for loads with high inrush, like motor starters and transformers, so it won't nuisance-trip on startup.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system — 4 modular width units (72 mm wide) — and can be mounted in any position. Depth is 76 mm (installation depth 70 mm). IP20 with connected conductors, so it's suited for enclosed distribution boards, not washdown areas. The combined top and bottom terminals accept the same conductor range, which simplifies panel wiring.