What the ratings mean for fit
The 5SY4203-7CC: The 10 kA breaking capacity per EN 60898 at 400 V AC means this MCB can safely interrupt fault currents up to 10,000 A in a 400 V AC circuit — standard for branch-circuit protection in industrial control panels. The C-curve (trips at 5–10× rated current) is sized for moderate inrush loads like small motors or transformers, not purely resistive circuits. The 2-pole design switches both line conductors simultaneously; there's no neutral switching, so it's for line-to-line loads or two-phase distribution. At 36 mm wide (2 MW), it fits standard DIN-rail enclosures with predictable fill factor. Depth of 76 mm means it clears most 80 mm deep enclosures — check gland plate clearance if back-panel wiring is tight. Mounting position is any, so it works in horizontal or vertical panel layouts without derating.
Integration notes
Mounts on a DIN rail via the quick assembly system — snaps on and off without tools. The combined terminal top and bottom accept copper conductors; the sealable design allows lockout/tagout for maintenance isolation. The IP20 rating (with connected conductors) is standard for enclosed panel use — not for wet or washdown areas. Rated for overvoltage category III and pollution degree 3, so it's suited for fixed installations in industrial environments where transient overvoltages and conductive dust are expected. Vibration resistance per IEC 60068-2-6 covers typical machine-mounted panels.