What this 5SY6 MCB carries — and what that means for the panel
The Siemens 5SY6110-6 is a 1-pole SENTRON miniature circuit breaker with a B tripping characteristic, rated 6 kA per IEC/EN 60898-1 and 15 kA per IEC 60947-2 — the higher figure is what governs when you're coordinating downstream of a transformer or in an industrial sub-distribution where fault currents run hotter than a residential service entrance. That B-curve means it trips magnetically between 3× and 5× In — standard for lighting, control transformers, and general-purpose final circuits where you don't want nuisance trips from inrush but still need fast clearing on a dead short. Rated operating voltage is 400 V AC single-phase, with a DC rating of 60 V (72 V max).
Breaking capacity across standards — the real-world headroom
Under UL 1077 and CSA C22.2 No. 235 the interrupting rating is 5 kA at 277/480 V AC — that's the number a North American panel designer reads for supplementary protection. The 6 kA per EN 60898-1 covers the domestic and light commercial install base; the 15 kA per IEC 60947-2 is the industrial duty rating. If your BOM calls for a 10 kA minimum at 400 V, this part clears it with headroom.
Panel fit and environmental tolerance
Installation depth is 70 mm. That -40 °C floor matters for unheated warehouse or cold-storage line-side panels — most residential-grade MCBs stop at -25 °C.
Certified to IEC/EN 60898-1, IEC/EN 60947-2, and UL 1077. Overvoltage category III. Energy limitation class 3.