The Siemens SENTRON 5SQ2270-0KA01 is a 2-pole miniature circuit breaker (MCB) with a C-curve tripping characteristic, rated at 1 A and 400 V AC, 50 Hz. It switches the neutral conductor as well as the line, per the product function.
The 1 A rated current at AC and C-curve (magnetic trip at 5–10× In) suit it for protecting small inductive loads like contactor coils, signal transformers, or control-circuit branches — not motor feeders. Overvoltage category 3 and energy limiting class 3 are standard for final-circuit distribution panels.
The 55 mm installation depth and 2 width units (roughly 36 mm at 18 mm per unit) fit standard DIN-rail enclosures. Neutral conductor switching is built in, so no external link is needed for the neutral pole.