The interrupting capacity varies by system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V.
Temperature derating — the real continuous current
At 55 °C it derates to 39 A, at 60 °C still 39 A, at 65 °C it drops to 38 A, and at 70 °C it's 37 A. That's a gentle slope — only 3 A lost over a 25 °C rise — so the thermal margin is comfortable for most enclosed panel installations. If your enclosure runs hot (say, above 55 °C), plan for the 39 A ceiling rather than the nameplate 40 A.
It's a panel-mount MCCB — not a DIN-rail snap-on — so it bolts into a cutout or mounts on a backplate. Power loss is listed at 10.8 W maximum, which is modest for a 4-pole 40 A device and won't drive significant internal heating in a ventilated panel.
Voltage and application notes
The overcurrent release design is TM220, a thermal-magnetic type with fixed thermal and adjustable magnetic pickup; there is no ground-fault monitoring version and no N-conductor protection built in. Communication function is absent — this is a standalone breaker, not a metering or communicating device.