The Siemens SENTRON 5SY4302-7KK11 is a 3-pole miniature circuit breaker rated 2 A at 400 V AC with a C tripping characteristic. It's designed for branch-circuit protection in industrial control panels, mechanical engineering applications, and railway equipment — the design carries a railway-specific designation. Breaking capacity is 10 kA per EN 60898 (the standard for household and similar installations) and 35 kA per IEC 60947-2 (the industrial standard for low-voltage switchgear) — so it's rated for industrial fault levels, not just residential service. DC rating goes to 72 V with 15 kA per IEC 60947-2.
Mounts via the quick-assembly system — snaps onto DIN rail, 3 width units (54 mm wide), installation depth 70 mm, overall depth 76 mm. Accepts solid or stranded conductors from 0.75 mm² up to 35 mm², with combined terminals at both top and bottom — no special lug kit needed for that range. Sealable, touch-protected, and halogen-free / silicon-free construction. Mounting position is any; ambient temperature range is -40 to +70 °C, storage -40 to +75 °C. That wide thermal range matters for unheated enclosures or outdoor cabinets.