The Siemens 5SL6240-7YA is a SENTRON miniature circuit breaker (MCB) — 2-pole, C-curve, rated 40 A with a 6 kA breaking capacity at 230 V AC per IEC/EN 60898-1.
Panel integration
Snap-on DIN rail mounting, 2-pole width (2 x 18 mm modular units). The 76 mm depth leaves clearance for standard 80 mm deep enclosures. Neutral conductor is switched (1P+N design), so it fits split-phase or single-phase panels where the neutral needs overcurrent protection.
The C-curve (5–10x In) avoids nuisance tripping from motor inrush while still protecting branch wiring.