It's designed for residential and infrastructure panels where motor or transformer inrush currents need a higher magnetic trip threshold than a B or C curve provides. The D curve means the magnetic trip is set to 10–20 times In (40–80 A), so it won't nuisance-trip on startup surges but still clears a hard fault. Rated voltage is 400 V AC between phases, with a maximum of 440 V AC for multi-phase operation.
In a panel, that's sized for a branch circuit with a total load under about 2.8 kW (assuming a balanced three-phase load). The D curve is the key decision point here — if your circuit has a motor, transformer, or LED driver with a high inrush, a C-curve breaker might trip on startup. This one holds through that surge. Mount it inside a panel with an IP-rated enclosure.
Tightening torque is 2.5 to 3 N·m.