The Siemens SENTRON 5SL6525-7MB is a 1P+N miniature circuit breaker rated 25 A at 230 V AC, with a C-curve trip characteristic and 6 kA breaking capacity per EN 60898. It occupies 2 modular width units (36 mm) on a DIN rail and is designed for residential and infrastructure branch-circuit protection where neutral switching is required.
What the ratings mean for fit
The 25 A rating at 30 °C is the nominal current for continuous load; at 40 °C it derates to 23.25 A, and at 45 °C to 22.5 A — so if the breaker sits in a warm enclosure, you lose about 1.75 A per 10 °C above 30 °C. That matters when sizing for a panel with multiple breakers ganged together. The C-curve (tripping class C) means the magnetic trip engages at 5 to 10 times rated current, making it suitable for moderate inrush loads like small motors, fluorescent lighting, or transformer banks — not for pure resistive loads (B-curve) or high-inrush transformers (D-curve). The 6 kA breaking capacity per EN 60898 (also 6 kA per IEC 60947-2) tells you the breaker can safely interrupt a fault current up to 6 kA at 230 V AC. That is standard for residential and light commercial distribution boards; if your available fault current exceeds 6 kA, you need a higher-rated upstream breaker or a current-limiting device. The 1P+N design switches the phase and switches the neutral, but the neutral pole does not have overcurrent protection — it is a switched neutral only. That is common in single-phase final subcircuits where the neutral must be disconnected for isolation but does not need its own trip element.
Mounting and integration
Mounts on a 35 mm DIN rail per EN 60715. The 36 mm width (2 modular units) and 70 mm installation depth leave room for adjacent breakers and busbar links. IP20 with connected conductors — fine for enclosed distribution boards, not for wet or dusty environments. Any mounting position is allowed, which simplifies layout in tight enclosures. Sealable design allows the breaker to be locked in the OFF position for lockout/tagout procedures. Touch protection is integrated, so accidental contact with live terminals is prevented when the breaker is properly installed.