The Siemens 5SY6320-6CC is a 3-pole miniature circuit breaker (MCB) from the SENTRON family, rated 20 A with a B tripping characteristic. It interrupts fault currents up to 6 kA at 400 V AC per EN 60898, which means it clears a short-circuit fast enough to protect downstream wiring in a standard commercial or light-industrial distribution board. The B-curve trips between 3 and 5 times rated current — 60 to 100 A — so it's sized for resistive and general-purpose loads where you don't want nuisance trips from modest inrush. It also carries a 5 kA interrupting rating per UL 1077 and CSA C22.2 No.235, covering North American panel builds.
Humidity tolerance is specified: max 95% RH at 55 °C, derating to 35% at 75 °C. Vibration resistance per IEC 60068-2-6 at ±1 mm from 5 to 25 Hz and 50 m/s² from 25 to 150 Hz — solid for machinery-mounted panels.