Arc fault detection add-on block for 25 A circuits
The Schneider Electric A9TAB1625 is an Acti9 ARC iC40 arc fault detection add-on block, rated 25 A, 1P+N, designed to clip onto a DIN rail alongside a compatible MCB. It detects series and parallel arcing faults per EN/IEC 62606 and trips the associated breaker — no separate enclosure needed, and the local signalling (ON, OFF, fault trip LED with arc fault diagnostic) tells you exactly what happened without guessing.
The 25 A rated current matches the MCB it pairs with — this is an add-on block, not a standalone breaker, so the amp rating must match the upstream MCB exactly. The 36 mm width (2 x 9 mm pitches) means it occupies two module spaces on the DIN rail; the 73 mm depth and 91 mm height fit standard distribution board cutouts.
Clip-on mounting to DIN rail, neutral on the left, electrical connection to the MCB by screws. Tunnel terminals accept 1…10 mm² flexible or 1…16 mm² rigid, with a wire stripping length of 14 mm and a tightening torque of 2 N·m.