The A9L16571 is a Schneider Electric Acti9 iPRD Type 2 surge arrester, single-pole, rated 230 V AC at 50/60 Hz. It uses MOV technology to clamp surges, with a nominal discharge current of 5 kA and a maximum discharge current of 20 kA (common mode L/PE).
The 20 kA maximum discharge current (Imax) tells you the arrester can survive a single large surge without failing short — important for locations with high lightning exposure. The 5 kA nominal discharge current (In) is the rating for repeated surge events; it defines the endurance of the MOV block. The voltage protection level (Up) is under 1.1 kV, which means downstream equipment with a 1.5 kV impulse withstand (IEC 60664-1 category III) is adequately protected. The maximum continuous operating voltage (Uc) is 340 V L/PE, so it handles nominal 230 V plus typical swells without degrading.
The 18 mm width takes one modular space, and the 69 mm depth fits typical distribution boards without crowding the gland plate. Tunnel-type terminals on both sides accept 2.5 to 35 mm² conductors — solid or stranded. Tightening torque is 2.5 N·m. The white RAL 9003 housing matches the Acti9 family look. Earthing system compatibility is TT and TN-C, so it suits most European residential and light commercial networks.