The Siemens 5SL4120-8CC is a 1-pole miniature circuit breaker from the 5SL4 Basic Devices family, rated for 230/400 V with a 10 kA breaking capacity and a D characteristic at 20 A. The D curve means it tolerates high inrush currents — think motor starting or transformer energisation — without nuisance tripping, while still clearing a fault fast. This is the one you spec for a motor branch circuit or a control transformer primary where the load draw spikes on start-up.
Compliance and Documentation
RoHS compliant since 01-06-13. REACH Article 33 disclosure: contains lead (CAS-No. 7439-92-1) above 0.1% w/w in the candidate list. Export control is straightforward — AL: N / ECCN: N — no special licensing for most destinations. The compliance pack covers the EU directives and the substance declarations a quality-doc-control review expects.