What it is and what it does
The Siemens 5SL6525-6 is a SENTRON miniature circuit breaker (MCB) with a 1P+N pole configuration, rated at 25 A and a B tripping characteristic. It switches the line and switches the neutral, intended for final-circuit overcurrent and short-circuit protection in residential and light commercial infrastructure.
Key ratings and what they mean for fit
Breaking capacity is 6 kA per EN 60898 and IEC 60947-2 — that's the maximum prospective fault current the breaker can safely interrupt without welding or arcing over. For a 230 V AC single-phase supply, that covers the vast majority of domestic and small commercial service-entrance faults. The B-curve trips between 3 and 5 times rated current (75–125 A), so it's a good match for resistive and lighting loads where inrush is modest. Rated operational voltage is 230 V AC, with a maximum of 250 V in single-phase operation. Frequency range is 50/60 Hz. For DC applications the maximum rated voltage is 72 V — useful if you're protecting a small DC subcircuit, but this is primarily an AC breaker. Power dissipation is 2.8 W per pole in hot operating state at rated current. In a multi-breaker enclosure, that adds up — account for it in thermal calculations if you're packing several units side by side.
Physical integration and mounting
The 5SL6525-6 occupies 2 modular width units (36 mm total) on a DIN rail. Depth is 76 mm, installation depth 70 mm. Height is 90 mm. Mounting position is any — no derating needed for horizontal or inverted orientation. Sealable cover is standard; halogen-free and silicon-free construction. IP20 protection with connected conductors — fine inside a distribution board or enclosure. Overvoltage category III and pollution degree 2 are standard for fixed-installation MCBs. Mechanical service life is 10,000 operating cycles typical.