B-curve tripping and breaking capacity
The Siemens 5SY6520-6 is a B-curve miniature circuit breaker from the SENTRON family, designed for 2-pole 1P+N operation with neutral conductor switching. The B characteristic trips between 3 and 5 times rated current, making it the standard choice for resistive and general-purpose loads in commercial and industrial panels — not for motor-starting inrush, where a C or D curve would be called for. Breaking capacity is rated at 6 kA per IEC/EN 60898-1 and 15 kA per IEC 60947-2 at 230 V AC. Under DC conditions at 60 V, the IEC 60947-2 rating holds at 15 kA. That dual rating means the 5SY6520-6 can be specified into a panel requiring either standard (60898-1) or industrial (60947-2) fault-current handling, with the higher 15 kA figure typically governing the SCCR calculation for the branch circuit.
Mounting and integration
Occupies 2 modular width units (36 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. The quick-assembly fastening system and combined top/bottom terminals simplify busbar and ring-tongue wiring in crowded enclosures. IP20 with connected conductors; pollution degree 3 and overvoltage category III suit it for fixed-installation panels in industrial environments.