What the ratings mean for fit
The Siemens 5SP3335-3 is a SENTRON 3-pole miniature circuit breaker rated 35 A at AC 400 V with a breaking capacity of 25 kA per EN 60898. That 25 kA figure is the maximum prospective short-circuit current the breaker can safely interrupt — critical for panels with high available fault current, like main distribution boards or industrial sub-distribution. The tripping characteristic E means the thermal-magnetic trip curve is tailored for moderate inrush loads; it holds through short-duration surges (e.g., motor starting, transformer energization) while still tripping fast on hard faults. This is the middle ground between a B curve (lighting/socket circuits) and a Z curve (high-inrush heavy equipment).
Deployment context and integration
Snaps onto 35 mm DIN rail per EN 60715 — standard for any industrial or commercial panel. The IP40 rating (with connected conductors) means it's protected against tools and solid objects larger than 1 mm but not sealed against moisture; keep it inside an enclosure rated for the environment. Terminal capacity handles solid or stranded conductors from 2.5 mm² up to 50 mm², covering a wide range of branch-circuit wire sizes. The integrated locking slide accepts a padlock, wire seal, or cable tie — useful for lockout/tagout on a panel main.