What it is and what it does
The Siemens SENTRON 5SY6314-7 is a 3-pole miniature circuit breaker (MCB) from the 5SY6 design series, with a C tripping characteristic and a rated current of 0.3 A at 400 V AC, 50/60 Hz. It's built for branch-circuit protection in industrial control panels, mechanical engineering, and similar environments where you need a compact, reliable overcurrent device that clears faults fast.
Key ratings — what they mean for fit
The C-curve means the magnetic trip fires at 5 to 10 times rated current — 1.5 to 3 A for this 0.3 A unit. That's the standard choice for moderate inrush loads like small motors, transformers, or lighting banks where you need to ride through the start-up surge without nuisance trips, but still clear a hard short quickly. Breaking capacity is 6 kA per EN 60898 and 30 kA per IEC 60947-2. The 30 kA figure is the one that matters for industrial panel coordination — it tells you this MCB can safely interrupt a fault up to 30 kA under the industrial standard, giving you headroom for high-fault installations without cascading upstream. UL 1077 rating is 5 kA for North American acceptance. Rated voltage is 400 V AC with a maximum DC rating of 72 V. Overvoltage category III and pollution degree 3 mean it's rated for fixed installations in industrial environments — think main distribution panels, not clean-room electronics.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system, 3 width units at 54 mm wide. Mounting position is any — no derating for horizontal or inverted orientation. Depth is 76 mm with 70 mm installation depth, so it clears standard 80 mm deep enclosures. IP20 with connected conductors — fine for enclosed panels, not for wet areas. Combined terminals top and bottom accept both busbar and cable. Sealable for lockout/tagout. Halogen-free and silicon-free — relevant if you're specifying for clean-room or corrosive environments where outgassing matters.