The Schneider Electric A9L16561 is an Acti9 iPRD40r Type 2 surge arrester — a 1-pole MOV-based unit rated for 230 V AC (+/- 10 %) at 50/60 Hz, with a maximum continuous operating voltage of 340 V common mode (L/PE and N/PE). It handles a nominal discharge current of 15 kA (common mode L/PE and N/PE) and a maximum discharge current of 40 kA (L/PE), with a voltage protection level below 1.4 kV (L/PE). The unit clips onto a DIN rail, occupies 18 mm width (2 x 9 mm pitches), and uses tunnel-type terminals accepting 2.5 to 35 mm² conductors on both top and bottom. It includes a remote signaling contact (1 SD, 1 C/O) rated 0.25 A / 250 V AC, and is designed for TN-C and TT earthing systems in electrical distribution networks.
The A9L16561 is classified as obsolete by Schneider Electric. For a replacement, the buyer should evaluate the current Acti9 iPRD range — specifically a Type 2, 1P, 40 kA unit with remote signaling — and verify fit against the original's 340 V Uc and 15 kA In ratings.
The 40 kA Imax (maximum discharge current) tells you the worst-case surge this unit can survive once without failing — it's the let-through rating for a direct lightning strike on the line side. The 15 kA In (nominal discharge current) is the working rating: the surge magnitude the MOV can repeatedly clamp without degrading. For most industrial distribution panels, the 15 kA In is the number that governs long-term reliability. The 340 V Uc (maximum continuous operating voltage) means this arrester can be connected to a 230/400 V TN-C or TT system without overheating the MOV. On a 240 V line (common in older plants), the 340 V Uc still provides adequate margin — the MOV won't conduct at nominal voltage. The <1.4 kV Up is the residual voltage the arrester lets through to protected equipment during a surge.
The manufacturer specifies an associated circuit breaker for disconnection: an iC60N, iC60H, or iC60L rated 40 A curve C, with Icu from 10 kA to 25 kA depending on the breaker variant. This ensures the arrester can be isolated for cartridge replacement without de-energizing the whole panel. Compliance marks include KEMA-KEUR, NF, and OVE, plus conformance to EN 61643-11 and IEC 61643-11 — the governing standards for low-voltage surge protective devices (SPDs) in distribution networks. Operating temperature range is -25 to 60 °C, storage -40 to 85 °C, with relative humidity 5 to 90 %. The IK03 impact rating (per IEC 62262) means the enclosure withstands a 0.35 J impact — adequate for a protected panel interior, not for exposed outdoor mounting.