The Schneider Electric A9N19648 is an Acti9 DPN Vigi RCBO — a combined overcurrent and earth-leakage protective device in a single 1P+N module, rated 40 A at 30 °C with a C-curve magnetic trip (5...10 x In) and 300 mA residual current sensitivity, Type A-SI (Super Immunised). The 6 kA Icn breaking capacity at 230 V AC per EN 61009 covers most residential and light commercial distribution boards; the 300 mA sensitivity is sized for general circuit protection rather than personal shock protection (which calls for 30 mA), so this unit suits submain or feeder circuits where the goal is fire prevention and equipment protection, not direct touch protection. Type A-SI (Super Immunised) means the residual current detection is immune to high-frequency leakage from switched-mode power supplies, VFDs, or LED drivers — a common nuisance-trip source in modern panels. It detects AC sinusoidal and pulsating DC fault currents (Type A) plus the SI immunity layer, so it holds steady on circuits with electronic loads that would trip a standard Type A.
Rated for 2000 m operating altitude and 95 % relative humidity at 55 °C, with tropicalisation level 2 per EN 61009 — so it holds up in coastal or high-humidity plant rooms without derating for condensation.