The C40V32D250 is a 3-pole ComPacT NSX moulded-case circuit breaker rated 250 A at 40 °C, fitted with a MicroLogic 2.3 electronic trip unit. The 2.3 provides L (long-time overload), So (short-time short-circuit with fixed delay), and I (instantaneous short-circuit) protection — three curves in one unit, so you set overload pickup and time-band separately from the short-time delay, which lets you coordinate downstream feeders without sacrificing speed on hard faults. Breaking capacity is 85 kA Icu at 500 V AC, 80 kA at 525 V, and 75 kA at 690 V — all per IEC 60947-2. If a downstream fault clears and the breaker is reclosed within that window, the memory prevents nuisance tripping on a second overload while the conductors are still hot. That matters on motor circuits or feeder groups where sequential starts are common.
Mounts on a backplate in either horizontal or vertical orientation — flat on the back, no DIN-rail adapter needed. The 140 mm width and 255 mm height fit standard distribution panel cutouts; 110 mm depth leaves room for rear-connected busbars. Front connections on both upside and downside simplify bus-strap routing in a multi-breaker lineup. IP40 front face (IK07 impact rating) suits indoor panel installation where tools or dropped parts are a risk.
Mechanical endurance is 15,000 cycles; electrical endurance at rated current is 6,000 cycles at 440 V and 3,000 cycles at 690 V. That is typical for a 250 A frame in distribution duty — not intended for frequent switching like a contactor, but more than adequate for infrequent manual disconnect or backup breaker operation.