It protects a single pole (1P, 1D protected) against overload (thermal element L) and short-circuit (magnetic element I). The 18 kA Icu at 220/240 V AC (50/60 Hz) per IEC 60947-2 tells you it can safely interrupt faults up to that level without welding or rupturing — enough for most distribution panels fed from a transformer of moderate size. At 250 V DC it handles 36 kA Icu, so it also works on DC bus or battery circuits where the arc is harder to extinguish. The 35 mm width and 161 mm height let it slot into a standard backplate-mounted panel alongside other ComPacT units. IK07 impact rating means it survives a hard knock from a dropped tool during panel work.
If your panel runs hotter, you derate — the TM-D curve shifts. Power dissipation is 5.47 W per pole, so a 1-pole unit dumps about 5.5 W into the enclosure. In a dense panel with multiple breakers, that heat adds up — account for it in the thermal budget. The electrical durability is 20,000 cycles at rated current and 10,000 cycles at twice rated current; mechanical durability is 20,000 cycles. That is typical for a fixed-mount distribution MCCB — not a switching device for frequent operations.
Overvoltage category IV means it can be installed at the service entrance or main distribution board where transient overvoltages are highest. Operating altitude is 0–2000 m without derating, 2000–5000 m with derating.