What this breaker is and where it fits
The Siemens 5SY7314-8 is a SENTRON miniature circuit breaker with a D tripping curve, 3 poles, and a dual-rated breaking capacity of 15 kA per IEC/EN 60898-1 and 50 kA per IEC 60947-2. It's designed for panel mounting via the quick assembly system — snaps onto DIN rail, occupies 3 modular width units (54 mm wide), and accepts supply from any position. The D-curve characteristic means it tolerates high inrush currents without nuisance tripping, so it's suited for motor circuits, transformers, and other inductive loads in mechanical engineering and industrial applications.
Breaking capacity — what the dual rating means
This breaker carries two breaking capacity figures because it's certified under two standards. Per IEC/EN 60898-1 (the household and similar installations standard) it's rated 15 kA. Per IEC 60947-2 (the industrial control gear standard) it's rated 50 kA. The 50 kA figure is the one that governs in an industrial panel with high prospective fault current — it tells you the breaker can safely interrupt a fault up to that level without welding its contacts or rupturing. The 15 kA rating under 60898-1 is the lower bound for residential or light commercial distribution boards. For a machine builder or panel OEM, the 50 kA / 60947-2 rating is the number to size against.
Physical integration notes
Dimensions are 90 mm high, 54 mm wide (3 modular units), 76 mm deep, with a 70 mm installation depth. The housing is halogen-free and silicon-free, IP20 rated with connected conductors — standard for a DIN-rail MCB in a closed panel. Mounting position is any orientation. The combined terminal top and bottom accept conductors without special tools. Pollution degree 3 and overvoltage category III cover the typical industrial environment inside a control cabinet.