The Schneider C10H42D040 is a ComPacT NSX100H molded-case circuit breaker with a 40 A MicroLogic 2.2 electronic trip unit, four poles, and a 100 kA interrupting capacity at 240 V AC. At 415 V AC the breaking capacity is 70 kA Icu, and at 480 V AC it holds 65 kA Icu. The MicroLogic 2.2 trip unit provides LSI protection: long-time overload (L), short-time short-circuit with fixed delay (So), and instantaneous short-circuit (I). No earth-leakage protection is built in, so if ground-fault detection is required, add a Vigi module or external relay. Above 40 °C, derate per the IEC 60947-2 thermal curve. The 4P configuration places the neutral on the left, and the device is category A (no intentional short-time delay for selectivity with downstream breakers — selectivity relies on the MicroLogic's adjustable curves).
Deployment context: panel integration and environment
Mounts on a backplate in any orientation — horizontal, vertical, or flat on the back. The 140 mm width, 161 mm height, and 86 mm depth fit standard distribution panel cutouts; the 35 mm connection pitch matches busbar systems and common terminal blocks. IP40 enclosure protection means it is suitable for indoor panels where no water spray is present; the IK07 impact rating handles accidental tool strikes during commissioning. Connections are front-access both top and bottom, so the breaker can be wired without reaching behind the panel. Five accessory slots accept auxiliary contacts, shunt trips, undervoltage releases, or communication modules — leaving room for future expansion without swapping the breaker frame.
The NSX100H frame (100 A frame, H breaking capacity) is the same mechanical platform used across the 40 A to 100 A trip unit range. If a higher or lower amp rating is needed later, the MicroLogic 2.2 trip unit can be swapped without replacing the breaker base — but the order code C10H42D040 is fixed at 40 A. No direct pin-compatible second source exists; the ComPacT NSX is a proprietary Schneider design.
UL 60947-4-1 listing is also confirmed for 85 kA Icu at 240 V AC, 65 kA at 480 V AC, and 10 kA at 600 V AC.