The Siemens 5SY6325-8 is a SENTRON 5SY6 series miniature circuit breaker — 3-pole, D tripping characteristic, rated 25 A at 400 V AC. The D-curve means it tolerates inrush spikes up to 10–20× rated current before tripping magnetically, which makes it the right choice for motor starters, transformers, or welding equipment where the start-up surge would nuisance-trip a B or C curve. Breaking capacity is 6 kA per EN 60898 for general distribution, or 15 kA per IEC 60947-2 for industrial panel duty — so it can interrupt a fault up to that level without upstream damage. The 15 kA rating under 60947-2 is the one to spec for machine control panels where higher fault current is expected.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system — no tools needed for the rail, but the combined top and bottom terminals accept the usual ring or fork lugs. Mounting position is any, so it fits horizontal or vertical busbars without derating. Occupies 3 width units (54 mm). Depth is 76 mm, installation depth 70 mm from the rail face — check your enclosure depth before committing the BOM line. IP20 with conductors connected, so it's panel-internal only; not rated for washdown or outdoor exposure.
Environmental and compliance
Halogen-free and silicon-free construction — relevant for clean-room or sensitive electronics environments where outgassing matters. Ambient temperature range is -40 °C to 75 °C, with humidity derating above 55 °C (95% RH up to 55 °C, 55% at 70 °C, 35% at 75 °C). Overvoltage category III, pollution degree 3 — suitable for fixed installations inside industrial enclosures where conductive dust or condensation is possible. Sealable design allows lockout/tagout compliance.