The Siemens 5SY4406-8CV is a 4-pole miniature circuit breaker (MCB) with a D-curve trip characteristic and a 6 A rated current.
The 6 A rating governs the continuous load it can carry; the 15 kA Icu at 400 V tells you it can interrupt a bolted fault on a high-capacity industrial supply without needing an upstream current-limiting fuse. The 4-pole configuration (3 phases + neutral) suits three-phase distribution panels where neutral protection is required.
Deployment Context
Snap-on DIN-rail mount for standard 35 mm rail in distribution boards or sub-distribution panels. Rated for 400 V phase-to-phase, so it fits directly into a 400/230 V three-phase system without derating.