The Siemens SENTRON 5SL6220-7MB is a 2-pole miniature circuit breaker (MCB) with a C tripping characteristic, rated at 20 A, and a breaking capacity of 6 kA per EN 60898 at 400 V AC. It sits in the SENTRON family, designed for residential and infrastructure branch-circuit protection. The 70 mm installation depth into the panel leaves clearance for wiring and busbar connections. Rated for any mounting position, it's IP20 with conductors connected — standard for enclosed distribution boards.
For a residential or light commercial distribution board with a typical transformer impedance, this is adequate for most final subcircuits. The C-curve holds through the 5–10x In window, so a 20 A breaker won't nuisance-trip on a 100 A inrush for a few milliseconds — that's the design intent for general-purpose and small motor loads. Single-phase operation is rated at 250 V AC. DC operation is limited to 72 V maximum.
The 2 MW width (36 mm) means it occupies two adjacent 18 mm slots — check your distribution board's fill factor before laying out the row. The 70 mm installation depth allows clearance for rear-connected busbars and wiring ducts. Supplementary devices (shunt trips, auxiliary contacts, alarm switches) can be installed on the right side via the product extension interface. Degree of pollution 2 and overvoltage category III ratings confirm it's suitable for fixed-installation distribution boards where transient overvoltages from the mains are expected — typical for building electrical infrastructure.