Allen-Bradley 161S-DA04NPU Adjustable Frequency Drive

The Allen-Bradley 161S-DA04NPU Adjustable Frequency Drive is a legacy, compact VFD from Allen‑Bradley’s 161S family that provides adjustable speed control for small to mid-size AC motors. It accepts 200–230 VAC input on a 3‑phase supply and offers up to 1 HP (0.75 kW) of output, with a 4 A rating, and is mountable for panel installation. The 161S‑DA04NPU follows the familiar parameter-based control approach of the 161S line, including user-settable values such as Pd01 for the output frequency. This model is listed as discontinued by the manufacturer, which affects availability and the need to source spare parts through refurbishers or secondary channels. For integrators maintaining a classic Allen‑Bradley 161S installation, the DA04NPU represents the 4 A, 200–230 V class within that family and is documented in service literature that covers 161S parameter configurations.