ComPacT NSX 50 A MCCB — magnetic-only motor protection
It is designed specifically for motor protection, providing short-circuit (magnetic) protection only — no thermal overload element, so a separate motor starter or overload relay handles the thermal curve. The 50 A rating holds at 65 °C ambient, which is the standard temperature for panel derating; no further temperature correction is needed up to that point. Breaking capacity follows the N class: 90 kA Icu at 240 V AC, 50 kA at 480 V AC, and 10 kA at 600 V AC per UL 60947-4-1; IEC 60947-2 ratings run 50 kA at 415 V, 36 kA at 500 V, and 10 kA at 690 V. The IEC utilisation category is A — not intended for selectivity with downstream breakers on the same fault, but fine for radial motor feeds where coordination is handled upstream.
Mounting, dimensions, and environment
Mounts on a backplate — no DIN-rail adapter, so plan for drilled panel or a sub-plate. Dimensions are 161 mm H × 105 mm W × 86 mm D, with a 35 mm connection pitch between poles. Operating altitude 0–2000 m without derating, 2000–5000 m with derating — no issue for most plant-floor installations.