The Schneider Electric A9R52463 is a 4-pole Acti9 iID residual current circuit breaker (RCCB) rated for 63 A continuous current with 30 mA earth-leakage sensitivity. It operates on 400-415 V AC 50/60 Hz networks and uses voltage-independent residual current tripping technology — meaning the trip mechanism draws no power from the line; it reacts to the leakage current itself, which keeps it functional even if the neutral is lost upstream.
The 63 A [In] rated current and 30 mA sensitivity are the two numbers that decide whether this RCCB fits your distribution board. 63 A is the load it passes continuously without tripping — sized for a main incomer or a heavy subfeed on a 3-phase 400 V supply. The 30 mA sensitivity is the standard for general-purpose personnel protection (shock risk) per IEC 61008-1; it catches leakage down to 30 mA, which is below the threshold for ventricular fibrillation. In a 400 V panel with a typical upstream MCB rated at 10 kA or higher, this RCCB must be backed by an overcurrent device that limits let-through energy to 1500 A or less at the fault level. The instantaneous trip (no intentional time delay) means it clears leakage faults immediately, which is correct for personnel protection but can cause nuisance tripping on circuits with high inrush or capacitive leakage.
The 4-pole body occupies 8 x 9 mm pitches (72 mm wide), so it takes four module widths in a modular enclosure. Neutral is on the left (fixed position). Wire stripping length is 14 mm. The IP20 finger-safe rating on the body meets IEC 60529; inside a modular enclosure it achieves IP40. Padlocking provision is built into the toggle for LOTO lockout.