The Siemens 5SL4340-6 is a SENTRON 3-pole miniature circuit breaker rated 40 A with a B tripping characteristic, designed for 400 V AC systems and a 10 kA breaking capacity under both EN 60898 and IEC 60947-2.
The B-curve trips between 3 and 5 times rated current (120–200 A for this 40 A unit), making it the right choice for resistive and general-purpose loads where inrush is modest — lighting circuits, socket outlets, small heaters. It is not intended for motor starting or transformer primary protection where higher inrush would nuisance-trip a B-curve; that is what a C or D characteristic handles. Rated for 400 V AC three-phase (440 V max multi-phase) and 50/60 Hz, it covers standard European LV distribution. The 10 kA breaking capacity is the same under both EN 60898 (household-type) and IEC 60947-2 (industrial-type) standards — no derating needed between the two test regimes. Mechanical life rated at 10 000 operating cycles typical.
Physical fit and integration
Sealable, halogen-free, and silicon-free construction — useful for installations requiring low-smoke zero-halogen cabling or where silicone outgassing could contaminate sensitive contacts (e.g., relay or PLC environments).