Siemens SENTRON 5SY6620-8CC — 4-Pole 20 A D-Curve MCB
The Siemens SENTRON 5SY6620-8CC is a 4-pole miniature circuit breaker (3P+N) rated at 20 A with a D tripping characteristic, designed for AC circuits at 400 V rated voltage and 50/60 Hz. It provides a breaking capacity of 6 kA per EN 60898 and 5 kA per UL 1077 / CSA C22.2 No. 235, making it suitable for protecting motor circuits, transformers, and other inductive loads that cause high inrush currents. The D-curve trips between 10× and 20× rated current (200–400 A), which handles the magnetizing inrush of motors and power supplies without nuisance tripping — a common requirement in mechanical engineering and industrial panel builds.
Accepts any mounting position and any power supply cord orientation, which simplifies layout in crowded enclosures. Combined terminals at both top and bottom accept conductors without separate busbar connectors. Touch protection is built in. The neutral conductor is switched (3P+N), so the breaker isolates all poles including neutral — required in some regional wiring regulations and for full isolation during maintenance.
Rated for ambient temperatures from -40 °C to 75 °C, with derating for humidity: max 95% RH at 55 °C, tapering to 35% at 75 °C. Halogen-free and silicon-free construction reduces outgassing in sensitive environments like food processing or clean rooms.