The Siemens SENTRON 5SY6620-6 is a 4-pole miniature circuit breaker wired 3P+N, rated 20 A at 400 V AC with a B-curve trip characteristic. On a panelboard feeding lighting, small heaters, or control transformers, this is the right curve. Breaking capacity tells you the fault it can safely interrupt. This MCB carries 6 kA under EN 60898 (the household / commercial standard) and 15 kA under IEC 60947-2 (the industrial standard). It also carries a 15 kA DC rating per IEC 60947-2, which covers DC distribution in control panels. The quick assembly system and combined terminal top and bottom make for straightforward wiring.
Mounting position is any — upright, sideways, upside-down, the trip mechanism works the same. The neutral conductor is switched (3P+N), so you get full isolation on all poles. Sealable, halogen-free, silicon-free. Touch protection is built in. Vibration resistance per IEC 60068-2-6: ±1 mm at 5 to 25 Hz, 50 m/s² at 25 to 150 Hz.
The MCB carries ratings per EN 60898 (6 kA) and IEC 60947-2 (15 kA AC and DC). It also has a UL 1077 and CSA C22.2 No.235 rating at 5 kA for the North American market. The product designation per IEC 81346-2 and DIN EN 61346-2 is F (protective device). Compliance documentation (RoHS, REACH, UL file, IEC test reports) is available from the manufacturer or through the sourcing channel. The part is marked as halogen-free and silicon-free, which helps with outgassing requirements in sealed enclosures.