Siemens 5SJ6250-7 SENTRON MCB — 50 A, 2-Pole, C-Curve
The Siemens 5SJ6250-7 is a 2-pole miniature circuit breaker from the SENTRON 5SJ6 series, rated 50 A at 400 V AC with a C-curve tripping characteristic.
The C-curve means magnetic trip occurs between 5× and 10× In (250–500 A), so it coordinates downstream of a 63 A or 80 A upstream MCB without losing selectivity on moderate overloads. Maximum operating voltage is 440 V AC for multi-phase circuits; single-phase to neutral is limited by the 400 V line-to-line rating. Terminals accept solid or stranded conductors from 0.75 mm² up to 25 mm² — sized for the 50 A rating (typically 10 mm² or 16 mm² copper). The sealable terminal covers allow the installer to lock the screws after torquing, which some site specs require for tamper-proofing. Installation depth is 70 mm, fitting standard SENTRON distribution boards and most DIN-rail enclosures with that clearance. The 2-module width (36 mm on a standard DIN rail) occupies two positions in the panel schedule.
This is a DIN-rail mounted MCB for final subcircuit protection in commercial and light industrial panelboards — lighting, socket outlets, small motor loads, and control transformers. The IP20 rating (with conductors connected) means it lives inside a closed enclosure, not in a wet or dusty environment. Vibration resistance to 50 m/s² at 25–150 Hz and 60 m/s² at 10–150 Hz per IEC 60068-2-6 makes it suitable for installation on machinery panels subject to moderate vibration.