That C-curve means it handles moderate inrush — typical for motor starters, contactor coils, and small transformer loads — without nuisance trips, while still clearing short circuits fast. The 4-module width (72 mm) and 76 mm depth fit standard distribution boards. With connected conductors the IP20 protection is typical for enclosed panel use.
Derating and ambient conditions
Rated current holds at 4 A up to 45 °C, then derates to 3.9 A at 50 °C and 3.8 A at 55 °C. The surrounding temperature influence curve (max 95% RH to 55 °C, 55% RH to 70 °C, 35% RH to 75 °C) means this breaker can live in a hot panel corner without false tripping, provided humidity stays within the envelope. Vibration resistance per IEC 60068-2-6 (±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz) confirms it holds up on machine-mounted enclosures.