Siemens 5SY4220-7CC11 — 2-Pole C-Curve MCB, 10 kA, Current Production
The Siemens 5SY4220-7CC11 is a SENTRON miniature circuit breaker (MCB) in a 2-pole configuration, rated for 400 V AC with a C-curve tripping characteristic. Its 10 kA breaking capacity per EN 60898 means it can safely interrupt fault currents up to 10,000 A under standard test conditions — sufficient for most industrial distribution panels where the prospective short-circuit current stays within that limit. The C-curve (5–10× In) is the standard choice for moderate inrush loads like small motors, transformers, and lighting circuits; it avoids nuisance tripping on startup while still clearing fast on a hard fault. Designed for railway applications per the evidence, the breaker also carries a pollution degree 3 rating and overvoltage category III, meaning it's built for environments with conductive pollution (condensation, light dust) and for fixed installations downstream of the main distribution board. The 2-pole design switches both phase conductors but does not switch the neutral.
Mounting and Panel Fit
Occupies 2 modular width units (36 mm total width) on a standard DIN rail. Depth is 76 mm; installation depth behind the panel face is 70 mm. The quick-assembly fastening system means it snaps onto the rail without tools and can be mounted in any position. For a panel OEM planning fill factor: at 36 mm wide, 10 breakers fit per 360 mm of rail, leaving room for end clamps. The combined terminals at top and bottom accept both busbar and conductor connections without re-termination. IP20 with connected conductors — suitable for enclosed distribution boards; not rated for washdown or outdoor exposure without a secondary enclosure. The sealable feature allows a lead seal or tag to be fitted through the breaker housing, meeting some utility or railway requirements for tamper evidence.