The Siemens SENTRON 5SY6650-8CC is a 4-pole miniature circuit breaker (3P+N) with a D tripping characteristic, rated 50 A at 400 V AC. At 4 modular width units (72 mm wide, 76 mm deep, 90 mm tall), it occupies standard DIN-rail space — the same footprint as any 4-pole SENTRON 5SY series breaker. The neutral pole is switched (3P+N), so it disconnects the neutral conductor, which matters for TN-S or TT systems where you need full isolation on all live conductors.
Ambient temperature range -40 °C to +75 °C, with humidity derating above 55 °C (95% RH at 55 °C, tapering to 35% at 75 °C). Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz. Supplementary devices (aux contacts, shunt trips, alarm switches) can be installed on either side via the combined top/bottom terminals.
D-curve and load suitability
The D characteristic (tripping between 10× and 20× In) is the right choice for loads with high inrush: small motors, pumps, compressors, transformers, and discharge lighting. A C-curve breaker of the same rating would nuisance-trip on the same start-up surge.