The 40 A rated current (In) and B-curve magnetic trip (3–5 × In) mean it clears short-circuit faults quickly on resistive or lighting loads where inrush is low, while the integrated 30 mA earth-leakage protection covers personnel shock hazard per EN/IEC 61009-2-1. Thermal-magnetic trip technology gives two-stage protection: the thermal bimetal handles sustained overloads (e.g., a stalled motor or daisy-chained power strips), while the solenoid reacts to hard shorts. The 30 mA sensitivity is the standard threshold for socket-outlet circuits in most IEC-based codes — it catches leakage through a person touching a live conductor without nuisance-tripping on normal cable capacitance.
Clip-on mounting to DIN rail (EN 60715) with a 36 mm width — four 9 mm pitches — so it occupies two standard modular positions in a distribution board. The neutral is on the left (1P+N configuration), and the tunnel terminals accept 1–16 mm² rigid or 1–10 mm² flexible cable; strip 14 mm and torque to 2 N·m. IP20 on the body, IP40 inside the modular enclosure — fine for dry indoor panels, not for washdown zones.
The iCV40N device short name and the full order code A9DH3640 are the same part — use either for BOM entry. The 10,000-cycle electrical durability and 20,000-cycle mechanical durability give a reasonable service life for a distribution board that sees infrequent switching; if this RCBO is used as a daily disconnect, expect to replace it earlier.