The D-curve means the instantaneous trip threshold is 10–20× rated current — sized for loads that draw a heavy start surge, then settle. Rated 400 V AC single-phase, 440 V AC multi-phase, and 72 V DC maximum. That's another SKU that stays in the bin for motor branch circuits and high-surge lighting panels.
Rated 3 A at 30 °C ambient. At 40 °C the continuous current drops to 2.84 A; at 45 °C it's 2.76 A; at 55 °C it's 2.59 A. That derating curve is baked into the bimetal element — if the panel runs hot, size up one amp step. The breaker itself survives -40 °C to 75 °C storage and operates up to 55 °C with 95% humidity.
Snaps onto standard DIN rail — 18 mm width, one modular width unit. Mounting position any, so it works in vertical or horizontal busbar arrangements. Sealable, halogen-free, silicon-free. Touch protection built in. No neutral conductor switching — this is a single-pole line-side break only.