The Schneider Electric A9L8F492 is a Type 2+3 surge protection cartridge from the Acti9 iPRD F40 range, designed for electrical distribution networks. It plugs into a compatible iPRD F40r base (1P+N or 3P+N) and provides L-N (differential mode) protection using MOV technology. The integrated fuse means no separate external overcurrent protection is needed for the SPD path — one less part to spec and wire.
Rated for a maximum discharge current of 40 kA (differential mode L/N) with a nominal discharge current of 20 kA — this is the surge it can repeatedly handle without degrading. The < 25 ns response time means it clamps fast enough to protect sensitive electronics like PLC power supplies or fieldbus interfaces downstream. The voltage protection level (Up) is < 1.5 kV in differential mode. The temporary overvoltage (TOV) withstand is 340 V L/N for 5 seconds; above that it fails safely at 442 V for 120 minutes. Short-circuit withstand is 25 kA, so if a surge causes the MOV to fail short, the integrated fuse clears the fault without upstream breaker coordination issues. The cartridge fits a standard 18 mm wide module slot on the DIN rail via the base — one module width per pole.
This is the replaceable cartridge for the Acti9 iPRD F40r base. You do not mount it directly to the rail; it plugs into the base unit (mounting support: into SPD module). The base stays wired to the panel; the cartridge swaps in and out for replacement after a surge event. Local signalling uses a green flag for operating state and a red flag for fault indication — no need to break out a meter to check if the MOV is still good. Rated for earthing systems TT and TN-S, which covers the vast majority of industrial and commercial distribution boards. Relative humidity 5...95 % and altitude up to 2000 m are standard for this class.