Type 2 surge protection for distribution panels
The Schneider Electric A9L20300 is an Acti9 iPRD20 Type 2 surge arrester with pluggable cartridges, designed for 3-phase distribution networks at 400 V AC (+/- 10 %) 50/60 Hz. The MOV + GDT technology handles a nominal discharge current of 5 kA per mode and a maximum discharge current of 20 kA in common and differential modes, with a voltage protection level below 1.4 kV.
The 20 kA Imax (maximum discharge current) tells you this arrester can safely divert a single high-energy surge up to that level without failing — critical for main distribution boards in areas with moderate lightning exposure. The 5 kA In (nominal discharge current) is the rating that defines its Type 2 classification per IEC 61643-11:2011; it's the current the arrester can withstand 20 times without degradation. The 350 V Uc (maximum continuous operating voltage) means it's rated for 400 V TN or IT systems, and the 337 V temporary overvoltage withstand for 5 seconds handles typical grid faults without needing a backup disconnector.
Mounts via clip-on DIN rail — standard for Acti9 enclosures. Tunnel-type terminals on both top and bottom accept 2.5 to 35 mm² conductors, tightened to 2.5 N.m. The 85 mm height and 69 mm depth fit standard 2-row enclosures. The white RAL 9003 housing carries IK03 impact resistance per IEC 62262, adequate for panel environments. The disconnector options listed include associated circuit breakers (iC60N/H/L or NG125H/L, 20 A curve C) or gG fuses up to 80 A — the back-up protection must be coordinated per the manufacturer's table.