The A9W21463 is an add-on residual current device (RCD) from the Schneider Electric Acti9 Vigi iC60 range, designed to bolt onto the side of an iC60 MCB via the supplied screws. It gives you 4-pole earth leakage protection rated at 63 A with a 30 mA trip sensitivity, Type A waveform detection, and instantaneous response — no intentional delay. That 30 mA sensitivity covers the standard personnel protection threshold; Type A means it catches pulsating DC fault currents that a basic AC-only RCD would miss, which matters on circuits feeding electronics, VFDs, or single-phase rectified loads.
Clip-on DIN rail mounting, 7 module pitches wide (135 mm). The 74 mm depth keeps it flush with the MCB it attaches to, so no extra enclosure depth needed. Tunnel terminals on the bottom accept up to 35 mm² rigid or 25 mm² flexible cable; strip 14 mm and torque to 3.5 N·m. IP20 on the terminals, IP40 on the modular enclosure — fine for a clean panel, but it's not washdown-rated, so keep it inside the cabinet.
Rated operational voltage is 400/415 V AC, 50/60 Hz — standard 3-phase mains in most of Europe and many other regions.
Tripping technology — voltage independent
The residual current tripping is voltage independent. That means the RCD will trip on a ground fault even if the phase voltage collapses or the neutral is lost upstream — it doesn't need the grid voltage to power its electronics. That's a real safety advantage on a construction site or a temporary supply where you can't guarantee the neutral reference.