Its interrupting capacity hits 121 kA at 240 VAC and 75.6 kA at 415 VAC — figures that place it squarely in high-fault-current applications like mains incoming feeders or large motor control center (MCC) bus ties.
At 415 VAC the breaker clears 75.6 kA; at 440 VAC it still manages 52.5 kA.
Thermal-magnetic release and derating
The overcurrent release is a TM240 — thermal-magnetic, fixed thermal pickup at 40 A, magnetic short-circuit trip set at 240 A (6× In). The breaker holds full 40 A through 50 °C ambient; at 55 °C it derates to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. That matters when the MCCB is packed into a high-density panel with other heat sources.
Physical fit and auxiliary contacts
Footprint is 76.2 mm wide, 130 mm tall, 70 mm deep — standard 3-pole MCCB width for a 40 A frame.