20 A C-curve MCB for branch-circuit protection
The Siemens SENTRON 5SL6120-7RC is a 1-pole miniature circuit breaker rated 20 A with a C tripping characteristic and a 7.5 kA breaking capacity per EN 60898.
Rated 415 V AC max single-phase, 440 V AC multi-phase — covers 400/415 V three-phase panels with the hot leg landed on this pole. DC rating tops out at 72 V, so it works in 48 V control circuits but not 125 V DC substation gear. The 7.5 kA breaking capacity at 415 V AC per EN 60898 is enough for most residential and light-commercial service entrances; if your available fault current runs higher, step to the 10 kA variant. Power loss per pole is 1.7 W at rated load in hot condition — negligible in a populated panel but worth a glance if you're packing 40+ breakers in a sealed enclosure.
Depth is 76 mm, height 90 mm — fits standard distribution boards and sub-panels without crowding the wiring gutter.