SENTRON 5SY6540-7CC – C-curve MCB, 1P+N, 6 kA
The Siemens SENTRON 5SY6540-7CC is a miniature circuit breaker with C tripping characteristic, rated 6 kA breaking capacity per EN 60898 at 230 V AC. The 1P+N design switches both line and neutral, with the neutral pole switching but not protected — common for single-phase final subcircuits where the neutral must be disconnected for isolation. It occupies 2 modular width units (36 mm) on a DIN rail, with any mounting position allowed. For North American installations, the 5SY6540-7CC carries a 5 kA interrupting rating per UL 1077 and CSA C22.2 No.235 — sufficient for most commercial and light industrial panelboards. The C-curve (5–10× In) suits moderate inrush loads like small motors, transformers, and lighting banks where a B-curve might nuisance-trip.
Dimensions and mounting
Panel cutout and enclosure planning: depth 76 mm (70 mm installation depth behind the panel), width 36 mm (2 MW), height 90 mm. The quick-assembly system snaps onto standard 35 mm DIN rail; combined top and bottom terminals simplify daisy-chaining busbars. IP20 with connected conductors — this is a panel-internal device, not for wet or outdoor locations without an enclosure.
Environmental and compliance
Mechanical endurance 10,000 operating cycles typical. Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz. Sealable design allows lockout/tagout with a padlock hasp. Power loss 3.5 W per pole at rated current in hot condition — factor into enclosure thermal calculations when grouping multiple breakers.