The C4044B400 is a MicroLogic 4.3 AB electronic trip unit for the ComPacT NSX400...630 range, rated 400 A at 40 °C. It sits in a 4P fixed-mount breaker and carries integrated earth-leakage protection (Class A). The EN/IEC 60947-2 standard governs its short-circuit and coordination performance — that's the standard for low-voltage switchgear and controlgear, so the unit is designed for selective coordination in distribution panels. The long-time pickup (Ir) is adjustable from 260 to 400 A — that's the overload threshold. Short-time pickup (Isd) adjusts 1.5 to 10 x Ir, giving you a wide band for motor or feeder coordination. Instantaneous pickup (Ii) is fixed at 4800 A, which means it clears hard faults above that level without delay. Earth-leakage sensitivity (IΔn) and time delay (Δt) are both adjustable via the rotary switch on the front face. You can set neutral protection to 0.5 x Ir (3D + N/2), 1 x Ir (4D), or no protection (3D) — the protected poles description matches: 3D + N/2, 4D, or 3D.
Integration notes — panel fit and wiring
Fixed-mount breaker, 4P, neutral on the left. Pollution degree 3 per IEC 60947-1 — that's the typical industrial environment with conductive pollution, so no extra conformal coating needed in a standard IP40 enclosure. Network frequency is 50/60 Hz, rated operational voltage 440 V AC.