The Schneider Electric A9D18816 is an Acti9 IKQE RCBO — a combined residual current breaker with overcurrent protection in a 1P+N form factor. It carries a 16 A rated current at 50 °C and a 10 kA breaking capacity at 230 V AC, making it suitable for final subcircuits in TN earthing systems where both overload and earth-leakage protection are needed in one module.
The 16 A rating and Curve C trip characteristic mean this RCBO handles moderate inrush from resistive and light inductive loads — think lighting banks, socket circuits, small control transformers. The 10 kA Icn is the short-circuit capacity at 230 V AC; that's standard for distribution boards in most commercial and light industrial panels, but if your fault level upstream exceeds 10 kA you'll need a current-limiting upstream MCB or fuse to back it up. Earth-leakage sensitivity is 100 mA, integrated into the same unit — no separate RCCB needed. That's a higher threshold than the 30 mA used for personal protection; it's aimed at equipment protection or circuits where nuisance tripping from leakage is a concern. The thermal-magnetic trip handles overloads thermally and short-circuits magnetically, so response time follows the standard Curve C profile.
Clip-on mounting to DIN rail, 18 mm width — that's 2 x 9 mm pitches, so it takes two standard module slots. Neutral is on the left, which matters when you're laying out the busbar or connecting a pre-wired distribution block. Tunnel terminals accept up to 16 mm² rigid or 10 mm² flexible; strip length 13 mm, torque to 2 N.m. IP20 means it's for enclosure use only — no washdown rating.