The Schneider Electric A9L65401 is an Acti9 iPRD65r Type 2 surge arrester — a 4-pole (4P) MOV-based protector for TN-C-S earthing systems in electrical distribution networks. It clips onto a DIN rail and is rated for a 230/400 V AC (+/- 10 %) 50/60 Hz network. The 65 kA common-mode maximum discharge current (L/PE and N/PE) and 20 kA nominal discharge current define its energy-handling capacity for induced lightning surges and switching transients. The 350 V maximum continuous operating voltage (Uc) matches the phase-to-earth voltage in a 230/400 V system.
Type 2 (Class II) per EN 61643-11:2012 / IEC 61643-11:2011 means it is designed for fixed installation at the sub-distribution board — it handles induced surges, not direct lightning strikes (that is Type 1). The 20 kA nominal discharge current (In) is the rating that governs its service life under repeated surges; the 65 kA maximum (Imax) is the single-event survival limit. The 337 V temporary overvoltage (Ut) withstand for 5 seconds between L/N means it can ride through a brief voltage swell without failing short — important for networks with unstable supply. The N/PE safe failure mode at 1200 V for 200 ms ensures the arrester fails open rather than creating a phase-to-earth fault.
Tunnel-type terminals on both top and bottom accept 2.5 to 35 mm² conductors; tighten to 2.5 N·m. The remote signalling contact (1 C/O, rated 0.25 A / 250 V AC) lets a PLC or annunciator monitor arrester status without opening the panel.