Siemens 5SY4620-7CC — 20 A C-Curve MCB, 4-Pole, 10 kA
The Siemens 5SY4620-7CC is a SENTRON miniature circuit breaker with a 20 A rated current at 35 °C, C tripping characteristic, and 4 poles (3P+N) for 440 V AC multi-phase operation at 50/60 Hz. Its 10 kA breaking capacity per EN 60898 means it safely interrupts fault currents up to that level in a 400 V three-phase panel — sufficient for most commercial and light industrial sub-distribution boards. The C-curve (5–10× In) handles moderate inrush from motor starters and transformers without nuisance tripping, while still clearing fast on hard shorts. Rated current derates with ambient temperature: 20 A at 35 °C, 18.8 A at 40 °C, 18.18 A at 45 °C, 17.52 A at 50 °C, and 16.84 A at 55 °C. If the panel runs warm, size up accordingly — the 20 A marking is only valid at 35 °C.
Panel Fit and Mounting
Occupies 4 modular width units (72 mm wide) on a DIN rail, with a quick assembly system for snap-on mounting in any position. Installation depth is 70 mm; overall depth is 76 mm. The combined terminal top and bottom accepts conductors, and the neutral pole is switched (3P+N). Pollution degree 3 and overvoltage category III suit it for fixed installations in industrial control panels. Sealable design allows lockout/tagout. Halogen-free and silicon-free construction avoids corrosive off-gassing in enclosed cabinets. Operating temperature range -40 to 75 °C, with humidity derating above 55 °C.