D-curve 4 A, 3-pole — what it handles
The 5SY4304-8: That 10 kA figure is the standard for branch-circuit protection in most industrial panels — it clears a bolted fault before the upstream device has to intervene.
Breaking capacity and DC rating
For DC circuits it's rated 15 kA at 60 V (max 72 V), which covers control-power and battery-backed bus protection. The 3-pole design switches all three phases simultaneously — no neutral pole.
Panel fit and environmental range
The 5SY4304-8 is certified to IEC / EN 60898-1 (domestic and similar installations) and IEC / EN 60947-2 plus UL1077 (industrial and supplementary protection). That dual rating means it can serve as a branch-circuit breaker in a UL 508A panel or as a final-subcircuit breaker in a European-style distribution board.