The Siemens 5SY4101-8CV is a 1-pole miniature circuit breaker (MCB) with a D-trip characteristic and a 1 A rating, designed for 230/400 V AC systems. Its interrupting capacity is rated at 15 kA, which means it can safely clear a fault current up to that level without welding contacts or cascading failure upstream — a key spec for coordination studies in distribution boards where high prospective short-circuit current exists.
Snap-mounts onto standard 35 mm DIN rail per EN 60715, fitting into any distribution board or sub-panel enclosure. The D1 curve (10–20× In magnetic trip) is sized for loads with high inrush — typically motor starters, small transformers, or lighting ballasts — where a B or C curve would nuisance-trip on startup.