The Siemens SENTRON 5SJ3620-7 is a 20 A miniature circuit breaker with a C tripping characteristic, designed for 3P+N (4-pole) 400 V AC circuits.
Rated 20 A at 400 V AC, this breaker handles a 3-phase+N load up to roughly 13.8 kW resistive. Breaking capacity of 4.5 kA per both EN 60898 and IEC 60947-2 tells you the breaker can safely interrupt a fault up to that level; if your available fault current at the panel exceeds 4.5 kA, you need an upstream current-limiting device or a higher-rated breaker. Insulation voltage rated 440 V AC gives headroom on 400 V systems. The 3P+N design switches all three phases and switches the neutral, which is required for TN-S or TT systems where you want the neutral isolated on a fault. Wire range accepts solid or stranded conductors from 0.75 mm² up to 25 mm² — covers everything from a 1.5 mm² lighting circuit to a 6 mm² sub-feed. The terminals are sealable, which matters for utility-metering or revenue-grade installations where the meter seal must stay intact. Touch protection is built in (IP20 with conductors connected), so the busbar area is finger-safe once the breaker is snapped onto the DIN rail.
Integration notes
Ambient temperature range of -20 to +45 °C covers unheated electrical rooms and outdoor enclosures in temperate climates; storage range extends to -40 to +75 °C. Vibration resistance tested to 50 m/s² at 25–150 Hz and 60 m/s² at 10–150 Hz per IEC 60068-2-6 — suitable for installation near rotating machinery or on shipboard panels.