Breaking capacity across standards
The 5SY4308-5: For UL 1077 applications, the rating is 5 kA. This means the same breaker can be specified into a panel designed to either residential (EN 60898) or industrial (IEC 60947-2) fault-current levels — a dual-certification that simplifies BOM consolidation when a panel ships to both markets.
Characteristic A trip curve and deployment
Characteristic A (tripping between 2 and 3 times rated current) is the most sensitive standard MCB curve — it catches low-level overcurrents faster than B or C curves. This makes the 5SY4308-5 a fit for protecting semiconductor loads, control transformers, or sensitive electronic circuits where a B-curve's 3–5× threshold would let a fault persist too long. The 3-pole design switches all three phases simultaneously, with no neutral pole. Rated operating voltage is 400 V AC (440 V max for multi-phase or single-phase operation), with a DC rating of 60 V (72 V max). The 50/60 Hz frequency range covers standard mains supplies globally.
Panel fit and environmental tolerance
The quick-assembly fastening system snaps onto the rail without tools. Mounting position is unrestricted — vertical, horizontal, or inverted — which helps when laying out a crowded enclosure.