The A9L1F900 is a Type 1+2 surge protection cartridge from the Acti9 iPRD1 F25r range, designed for electrical distribution networks. It handles impulse currents up to 25 kA per pole (differential mode) and clamps the let-through voltage below 1.5 kV, which is the key figure for protecting downstream equipment from lightning-induced surges. The integrated fuse means the cartridge is self-protecting against follow current up to 75 kA — no external overcurrent device is needed for the SPD branch.
The 25 kA nominal discharge current (In) and 65 kA maximum discharge current (Imax) define the surge-handling capacity in differential mode. The 75 kA short-circuit withstand rating confirms the cartridge can survive a bolted fault on the network without rupturing — critical for coordination with upstream breakers in a TN-S, TN-C, or TT earthing system. The temporary overvoltage withstand of 442 V for 120 minutes means it rides through a sustained line-to-neutral swell without failing, which is common on weak grids.
The cartridge plugs into the iPRD1 F25r base module (sold separately). It occupies 4 x 9 mm pitches (36 mm width) on a DIN rail, with a depth of 73.5 mm and height of 45 mm. The green/red flag indicators give local status — green for operating, red for fault — so a panel walk-by confirms the SPD is still protecting without opening the enclosure.