Siemens 5SY4480-7 — 4-pole C-curve MCB for industrial panels
The Siemens 5SY4480-7 is a 4-pole miniature circuit breaker from the SENTRON series, designed for branch-circuit and final-subcircuit protection in industrial control panels. It carries dual certification to IEC/EN 60898-1 and IEC/EN 60947-2, so it can be applied in either residential-style distribution boards (60898-1) or industrial switchgear assemblies (60947-2) without over-rating concerns. Rated 400 V AC with a C-curve trip characteristic, the 5SY4480-7 delivers 10 kA breaking capacity per EN 60898-1 and 15 kA at DC per IEC 60947-2. The C-curve (5–10× In magnetic trip) suits moderate inrush loads — motor starters, contactor coils, small transformers — where the instantaneous trip must ignore the short-duration surge but clear a hard fault fast. The 4-pole design switches all three phases plus the neutral (though neutral is not switched internally — the fourth pole is a switched neutral for isolation). Rated for 50/60 Hz, pollution degree 3, overvoltage category III. The breaker is sealable, halogen-free, and silicon-free, which simplifies compliance in food-and-bev or clean-room panels where outgassing is restricted.
Mounting and environmental fit
Snaps onto standard 35 mm DIN rail via the quick-assembly system; 4 MW (modular width units = 72 mm) occupies four 18 mm slots. Mounting position is any — vertical, horizontal, or inverted — so it fits tight gland-plate layouts. Installation depth is 70 mm; overall depth 76 mm including the terminal arc chamber. Combined top and bottom terminals accept Cu conductors; the IP20 rating applies only with connected conductors, so the panel door must shield live busbars. Ambient temperature range is -40 °C to +75 °C, with derating above 55 °C: max 95 % RH at 55 °C, 55 % at 70 °C, 35 % at 75 °C. Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz. Mechanical life is 10,000 operating cycles typical — adequate for most fixed-installation switchgear, but not for frequent switching duty (use a contactor for that).