The Schneider Electric A9N26479 is an MSU overvoltage release from the Librio Prodis Acti9 Clario range. It monitors the control circuit voltage and trips when it hits 255 V — a hard threshold, not adjustable. Mounts on 35 mm symmetrical DIN rail, 18 mm wide, 68 mm deep, 82.5 mm tall. White housing, clamp terminals accepting up to 2.5 mm² flexible cable, 9 mm strip length, 1 N·m torque.
Standards and deployment context
Rated to EN/IEC 60947-5-1, the standard for control-circuit devices and switching elements. That covers the overvoltage release's role in a panel: it sits on the DIN rail alongside contactors and relays, protecting downstream control logic from sustained overvoltage on the supply. The 255 V trip point is set for 230 V AC nominal systems where a voltage swell above that threshold could damage PLC inputs or coil-driven devices. Tropicalisation per the same standard, with 95 % humidity tolerance at 55 °C.