The Siemens SENTRON 5SL6503-7 is a 1P+N miniature circuit breaker rated 3 A with a C tripping characteristic, breaking 6 kA per EN 60898 and IEC 60947-2 at 230 V AC. That 6 kA rating is the same under both standards, so it covers residential and light commercial panelboards without needing separate coordination curves for each standard. The C-curve trips between 5× and 10× rated current — the right choice for mixed resistive and moderate inductive loads like lighting circuits and small appliance outlets where you want nuisance immunity from inrush but still fast clearing on a hard fault. It occupies 2 modular width units (36 mm) on a DIN rail, with a 70 mm installation depth behind the panel cover. The neutral pole is switched (1P+N), so the neutral is disconnected when the breaker is off — that's a requirement in several national wiring rules for final circuits. IP20 with connected conductors means it's protected against finger contact once wired; it's intended for enclosed distribution boards, not outdoor or washdown locations.
Mounts on a standard 35 mm DIN rail in any position. The 36 mm width (2 MW) leaves room for adjacent breakers or accessories in a multi-pole panel layout. Sealable with a lockable cover (per), which is useful for isolating a circuit during maintenance or preventing unauthorized switching in a shared enclosure. Halogen-free and silicon-free construction matters if the panel is in a clean room or a corrosive environment where outgassing could cause contact or sensor issues.
Rated for ambient temperatures from -40 °C to +75 °C, which covers most indoor and sheltered outdoor installations. Power dissipation is 1.2 W per pole at rated current in hot operating state — low enough that derating for adjacent breakers in a multi-pole assembly is minimal, but worth checking if the panel is densely packed and running near its thermal limit. Overvoltage category III and pollution degree 2 are standard for fixed-installation distribution boards.