The A9L20100 is a Schneider Electric Acti9 iPRD20 Type 2 surge arrester — a 1-pole MOV-based protector rated for 350 V maximum continuous operating voltage (Uc) on L/PE and N/PE paths. It is designed for electrical distribution network protection in IT and TN-C earthing systems at 230 V AC (+/- 10%) 50/60 Hz. The Type 2 classification means it handles induced surge currents from switching or indirect lightning strikes — not direct hits — and is typically installed at the sub-distribution board level.
The nominal discharge current (In) is 5 kA per mode (L/PE and N/PE), and the maximum discharge current (Imax) reaches 20 kA common mode on L/PE. That 20 kA figure is the one-shot survival limit — the arrester will clamp one big surge at that level, but repetitive events at Imax degrade the MOV. For daily duty, the 5 kA In rating is the design target. The voltage protection level (Up) is under 1.1 kV for Type 2 L/PE. This is the let-through voltage the equipment sees — lower is better. At 1.1 kV it is within expectations for a 350 V Uc MOV block, and it coordinates with downstream equipment rated for impulse voltages of 2.5 kV or higher per IEC 60664-1. Temporary overvoltage (TOV) withstand is specified at 337 V L/N for 5 seconds before safe failure, and 1200 V N/PE for 200 ms in safe failure mode. This means the arrester can ride through short-duration swells without catastrophic failure — important for industrial grids with generator transfers or capacitor bank switching.
Clip-on DIN rail mounting (per EN 60715) with tunnel-type terminals accepting 2.5 to 35 mm² on both top and bottom. The tightening torque is 2.5 N.m — a standard value for this conductor range, and the terminal design supports both solid and stranded copper. The 69 mm depth fits standard shallow enclosures. The arrester requires an upstream overcurrent protective device — either a circuit breaker (IC60N, iC60H, iC60L, or NG125H/L in 20 A curve C) or a gG fuse (40 A or 80 A depending on required Icu). This is not optional: the MOV block needs the disconnector to clear a fault if the varistor fails short. The associated device list covers Icu from 10 kA up to 50 kA, so you can match the SCCR of your panel.