The Siemens 5SJ6240-7 is a 2-pole SENTRON 5SJ6 miniature circuit breaker rated 40 A at 400 V AC with a C-curve tripping characteristic and 6 kA breaking capacity per both EN 60898 and IEC 60947-2. The C-curve means it trips between 5 and 10 times rated current — designed for moderate inrush loads like small motors, transformers, and lighting circuits where you need to ride through the startup spike without nuisance tripping. The 6 kA short-circuit capacity is the standard rating for most commercial and light industrial distribution boards; it safely interrupts faults up to that level without cascading upstream.
Snap-on DIN rail mounting, 2 width units (36 mm), installation depth 70 mm. Terminal capacity accepts solid or stranded conductors from 0.75 mm² up to 25 mm² — enough for the 40 A feed-through on the line side. The housing is IP20 with connected conductors, standard for enclosed distribution boards. Mounting position is any, which simplifies panel layout when the board is vertical or horizontal.
Rated for 50 Hz AC supply. Insulation voltage 440 V AC, overvoltage category III. The housing is halogen-free and silicon-free — relevant for panels in environments sensitive to outgassing (clean rooms, food processing, certain transit applications). Vibration resistance per IEC 60068-2-6: 50 m/s² at 25 to 150 Hz and 60 m/s² at 10 to 150 Hz. Ambient temperature range -20 to +45 °C; storage -40 to +75 °C.