The Schneider Electric C40H3TM400 is a ComPacT NSX400H 3-pole circuit breaker with a TM-D thermal-magnetic trip unit rated 400 A at 40 °C. Its breaking capacity hits 70 kA Icu at 380/415 V AC 50/60 Hz per EN/IEC 60947-2, and 100 kA Icu at 220/240 V AC — enough for high-fault utility feeds or transformer secondaries. The TM-D trip provides L (thermal overload) and I (magnetic short-circuit) protection in one block, no add-on electronic module needed.
At 690 V AC the Icu drops to 20 kA, so verify your system voltage against the full curve. Pollution degree 3 (IEC 60664-1) means it's rated for conductive pollution in industrial enclosures — no extra conformal coating needed inside a standard IP40 panel. Mechanical durability is 15,000 cycles, electrical durability 12,000 cycles at 440 V at half rated current (In/2) and 6,000 cycles at full In. That's typical for a distribution breaker — not a motor-switching duty cycle, but fine for infrequent manual isolation or backup protection.
Mounts on a backplate or DIN rail, horizontally or vertically, flat on the back. Front connections top and bottom — busbar or cable entry is straightforward in a standard distribution panel. The toggle handle gives clear contact position indication (open/closed/tripped).
The C40H3TM400 is current production per Schneider. It is part of the ComPacT NSX family.