The Schneider Electric A9TAB2640 is an Acti9 Active ARC iC40 arc fault detection add-on block — a 1P+N, 40 A device that clips onto a DIN rail and sits on the outgoing side of a panel, watching for the telltale signature of an arc fault and tripping the circuit when it sees one. It measures voltage, current, active power, and power factor, with accuracy of ±2 % on voltage and current and ±5 % on power — good enough to spot an arc without false-tripping on normal load changes.
The 73 mm depth, 36 mm width, and 91 mm height fit a standard 2-module DIN-rail slot (9 mm pitches: 2). Clip-on mounting means it snaps onto the rail next to the associated MCB — no tools needed for the mechanical fit. Terminals accept 1 to 16 mm² rigid or 1 to 10 mm² flexible cable, with a 2 N·m tightening torque and 14 mm strip length — standard for the Acti9 range.
It's built to EN/IEC 62606, carries the IMQ quality label, and is tropicalised to severity B per IEC 60068-2-30 for 28 days — so it handles humidity up to 95 % at 55 °C without degrading.