Siemens 5SL6250-6RC — 50 A, 2-pole, B-curve MCB for residential and infrastructure panels
The Siemens 5SL6250-6RC is a 2-pole miniature circuit breaker from the SENTRON 5SL6 family, rated 50 A at 415 V AC with a B tripping characteristic and a 7.5 kA breaking capacity per EN 60898. The B-curve trips between 3 and 5 times rated current, making it the standard choice for resistive and general-purpose loads in residential and light commercial distribution boards — lighting circuits, socket outlets, and small appliance feeds where inrush is low. At 36 mm wide (2 width units), it occupies two adjacent DIN-rail positions in a consumer unit or sub-distribution board. The 76 mm depth and 70 mm installation depth leave clearance for standard enclosure depths; the 90 mm height fits flush against the busbar riser.
B-curve selectivity and 7.5 kA SCCR — what the ratings mean for your distribution board
The B characteristic (3–5× In) means this breaker will hold through the brief magnetizing inrush of a small transformer or a bank of LED drivers, but it trips faster than a C-curve on a hard short — a deliberate trade-off for circuits where the load current is predictable and the fault current path is short. The 7.5 kA breaking capacity per EN 60898 is the maximum prospective fault current the breaker can safely interrupt at its rated voltage; in a typical UK domestic supply (6 kA at the cut-out), this provides headroom. For panels with a higher declared fault level, coordination with an upstream backup fuse or a current-limiting MCB is required. The 50 A rating on a 2-pole format suits sub-mains or high-current final circuits where single-pole switching is insufficient and a 2-module width is acceptable.
Panel integration — DIN-rail mount, 2-module width, any position
Mounts on 35 mm DIN rail per EN 60715. The 36 mm width (2 width units) and 70 mm installation depth fit standard consumer units and sub-distribution boards. Mounting position is unrestricted — vertical, horizontal, or inverted — which simplifies layout in tight enclosures. The IP20 rating (with connected conductors) means it is intended for dry indoor environments only; no washdown or outdoor exposure. Terminal capacity accepts 0.75 mm² to 25 mm², covering most final-circuit cable sizes up to 50 A.
Compliance and approvals — EN 60898, overvoltage category III, touch protection
Rated and tested per EN 60898 for the 7.5 kA breaking capacity. Overvoltage category III (distribution-board level) per IEC 60664. Touch protection is integrated — no live parts accessible with the breaker snapped onto the rail. Halogen-free and silicon-free construction, sealable for tamper-evident tagging. The 10 000 mechanical switching cycles cover typical residential and light commercial service life.