Siemens 5SY4240-7CC11 — SENTRON 2-Pole C-Curve MCB
The Siemens 5SY4240-7CC11 is a SENTRON miniature circuit breaker designed for 2-pole protection in AC circuits up to 400 V. Its C characteristic (tripping between 5 and 10 times rated current) suits it for moderate inrush loads like motor starters and small transformers in industrial control panels. The 10 kA breaking capacity per EN 60898 means it can safely interrupt fault currents up to that level — adequate for most sub-distribution boards in commercial and light industrial installations.
Panel Fit & Mounting — 2 MW Units, Any Position
Occupies 2 modular width units (36 mm) on a DIN rail. The quick assembly system snaps onto the rail without tools. Mounting position is any — no derating for horizontal or inverted orientation. Installation depth is 70 mm behind the panel surface; overall depth is 76 mm including the front projection. The combined terminals at top and bottom accept both busbar and conductor connections, which keeps wiring tidy in a crowded enclosure.
Environmental & Compliance — Railway-Rated, Wide Temperature Range
Rated for railway applications (per), meaning it meets the vibration and shock profiles of IEC 60068-2-6: ±1 mm at 5 to 25 Hz, 50 m/s² at 25 to 150 Hz. Temperature range is -40 °C to 75 °C, with humidity derating above 55 °C. Pollution degree 3 and overvoltage category III — suitable for fixed installations with non-conductive pollution. Halogen-free and silicon-free construction. IP20 with connected conductors — protected against finger contact, not for wet locations.
Power Loss & Selectivity — 3.5 W per Pole
Power loss is 3.5 W per pole at rated current in hot operating state. For a 2-pole breaker that's 7 W total — negligible in a ventilated panel but worth noting for high-density enclosures. Energy limitation class 3 means it limits let-through energy well, aiding downstream coordination. Mechanical service life is 10,000 operating cycles typical.