The Schneider Electric A9L40122 is a Type 2 surge protection device (SPD) cartridge from the Acti9 iPRD series, designated C40-460. It is designed for electrical distribution networks with IT earthing systems, clamping surges via MOV technology. Rated for a maximum discharge current of 40 kA and a nominal discharge current of 15 kA, with a voltage protection level under 2 kV. Response time is under 25 ns. The cartridge plugs into a compatible iPRD base module, making field replacement straightforward without disturbing the base wiring.
The 15 kA nominal discharge current (In) is the surge current the cartridge can withstand repeatedly under the standard test waveform. The 40 kA maximum discharge current (Imax) is the one-shot survival limit for a rare high-energy event. The 460 V maximum continuous operating voltage (Uc) means the cartridge will not degrade on a 400 V line. The under-2 kV protection level (Up) tells you the let-through voltage at the load terminals during a surge.
The cartridge measures 18 mm wide, 60 mm deep, and 60 mm high — it occupies a single 18 mm pitch in the base module. The local flag indicator shows white when healthy, red when the MOV has degraded and the cartridge needs replacement.