The Siemens 5SJ6240-7RC is a 2-pole miniature circuit breaker from the Retail line, rated at 40 A with a 6 kA breaking capacity and a C characteristic curve. The C characteristic means it trips at 5 to 10 times rated current, making it suitable for protecting circuits with moderate inrush loads like small motors, lighting banks, and distribution sub-panels where the startup surge would nuisance-trip a B-curve device.
This 2-pole MCB snaps onto standard 35 mm DIN rail per EN 60715, occupying two modular width units (36 mm). The C-curve coordination holds selectivity with downstream 16 A and 20 A B-curve MCBs in typical final-distribution layouts, provided the prospective short-circuit current stays within the 6 kA rating at the point of installation.