What it is and what it does
The Siemens 5SL3350-6 is a 3-pole SENTRON miniature circuit breaker (MCB) rated for 50 A at 400 V AC, with a B tripping characteristic and a breaking capacity of 4.5 kA per both EN 60898 and IEC 60947-2. The B curve means it trips instantaneously between 3 and 5 times rated current — a good fit for resistive or general-purpose loads in residential and infrastructure panels where inrush is moderate.
Ratings and what they mean for fit
At 50 A continuous and 400 V AC, this breaker handles standard single-phase or three-phase branch circuits up to that current. The 4.5 kA breaking capacity is sufficient for most residential and light commercial service entrances where the prospective fault current stays under that threshold. The B characteristic holds up to 2.5× In indefinitely and trips above 5× In. That avoids nuisance trips on lighting or heating loads. Terminals accept solid or stranded conductors from 0.75 to 25 mm², with a tightening torque of 2.5 to 3 N·m. The screw terminals are touch-protected, and the design is halogen-free and silicon-free — relevant for clean-room or low-smoke environments.
Panel integration and mounting
The 5SL3350-6 snaps onto standard DIN rail (EN 60715). It occupies 3 width units (54 mm) and has an installation depth of 70 mm plus a total depth of 76 mm, leaving clearance for wiring behind the panel door. Mounting position is any orientation, and the ambient temperature range is -25 to +45 °C, with periodic excursions to +55 °C at 95% humidity. The IP20 rating (with connected conductors) is typical for enclosed distribution boards. The breaker is sealable to prevent tamper — a feature for metering or security applications.