The Siemens SENTRON 5SL4150-6 is a 1-pole miniature circuit breaker rated 50 A with B-curve tripping characteristic, designed for 230/400 V AC systems. Its 10 kA breaking capacity is certified under both EN 60898 and IEC 60947-2, meaning it safely interrupts fault currents up to that level in residential or light commercial distribution boards. The single-module width (18 mm) fits standard DIN-rail enclosures, and the IP20 rating with connected conductors is typical for panel-internal mounting with no washdown exposure.
B-curve and breaking capacity — what they mean for the panel
The B-curve (tripping characteristic class B) means the magnetic trip fires at 3 to 5 times rated current — so for a 50 A breaker, instantaneous trip occurs between 150 A and 250 A. That makes it a good fit for resistive or general-purpose loads with modest inrush, like lighting circuits or small distribution subfeeds. It is not the right choice for motor circuits or transformer primaries that draw higher inrush; those want C or D curves. The 10 kA breaking capacity, rated per both EN 60898 and IEC 60947-2, gives you the same fault-interrupt rating under either standard — no derating needed when switching between residential (EN) and industrial (IEC) specs. That simplifies BOM coordination if the panel crosses both applications.
Mounting and integration
Single-module width (18 mm) on a standard DIN rail, any mounting position accepted. Installation depth is 70 mm, overall depth 76 mm — the extra 6 mm accounts for the front toggle and terminal clearance. Sealable design allows padlocking in the OFF position for LOTO compliance. The breaker accepts supplementary devices (auxiliary switches, shunt trips, under-voltage releases) via the accessory slot on the right side.
Environmental range and approvals
Rated for ambient temperatures from -40 °C to 75 °C, covering most indoor and sheltered outdoor enclosures. Halogen-free and silicon-free construction matters for sensitive environments like data centers or medical facilities where outgassing can damage contacts or optics. Pollution degree 2 and overvoltage category III are standard for fixed-installation distribution boards. The 4 W power loss per pole at rated current should be factored into enclosure thermal calculations when grouping multiple breakers.