Allen-Bradley 1769-OW81 Isolated Relay Output Module

The Allen-Bradley 1769-OW81 Isolated Relay Output Module is an eight-point relay output card for the Compact I/O 1769 bus that provides galvanically isolated contacts to switch AC or DC loads from a PLC while keeping the field wiring isolated from the backplane. Each of the eight outputs supports 5-265 V AC or 5-125 V DC, with two isolated groups (Group 1: outputs 0–3 and Group 2: outputs 4–7) and isolation between groups, enabling four loads per group with minimal cross-talk. The module delivers up to 2.5 A per output, and its turn-on and turn-off times are about 10 ms, with an on-state voltage drop of roughly 1.0 V at 1 A. It draws up to 125 mA from the 5 V backplane (0.625 W) or up to 100 mA at 24 V operation, contributing to a compact power footprint. Dielectric isolation between output points and the backplane is rated at 1836 V AC for 1 s or 2596 V DC for 1 s, and group-to-group insulation supports 265 V AC working voltage. The 1769-OW81 is designed to plug into a 1769 Compact I/O chassis, wiring field devices through standard screw terminals, and is commonly used to switch field devices such as motors, solenoids, and indicators in industrial automation systems.