The Siemens 5SY6220-7CC is a SENTRON miniature circuit breaker — 2-pole, C-curve, rated 20 A at 35 °C, with a 6 kA interrupting capacity per EN 60898 and a maximum operating voltage of 440 V AC.
The 6 kA breaking capacity is the maximum prospective fault current it can safely interrupt under EN 60898; for a 20 A branch circuit in a typical industrial panel fed from a 10 kA transformer, this breaker needs upstream coordination or a current-limiting device to keep the available fault below 6 kA. At 40 °C the continuous rating derates to 18.8 A; at 55 °C it's 16.84 A. The 2-pole design switches both phase conductors on a single-phase or split-phase circuit; neutral conductor switching is not provided. The 36 mm width occupies 2 modular units — standard 18 mm per pole — so it slots into any SENTRON distribution board without surprises.