The Siemens SENTRON 5SJ6240-6 is a 2-pole miniature circuit breaker rated 40 A at 400 V AC, with a B tripping characteristic and a 6 kA breaking capacity per EN 60898 and IEC 60947-2. The B-curve means it trips between 3 and 5 times rated current — intended for resistive or general-purpose loads where inrush is low, not for motor starting or transformer primaries. The 6 kA rating at 400 V AC covers most commercial and light industrial panelboards; if your fault current exceeds that, step up to the 5SJ6 range's higher-breaking variants. Mounts on standard DIN rail, occupies 2 width units (36 mm), and accepts conductors from 0.75 to 25 mm² solid or stranded. The terminals are sealable — useful for utility or metering applications where tamper evidence is required. Ambient temperature range is -20 to +45 °C, with periodic excursions to +55 °C at up to 95% humidity.
Integration notes
Installation depth is 70 mm — verify panel enclosure depth if using a shallow gland plate. The IP20 rating applies only with connected conductors; finger-safe terminals meet touch protection requirements. Overvoltage category 3 suits fixed-installation distribution boards. Vibration resistance per IEC 60068-2-6: 50 m/s² at 25 to 150 Hz and 60 m/s² at 10 to 150 Hz — adequate for most industrial control cabinets, but not for direct machine-mount without additional damping.