1771-P4S (PU)

Allen Bradley Bulletin 1771 | Internal Power Supply

Allen Bradley Bulletin 1771 | AC Power Supply Module, Input 120/220VAC, Output 5VDC @ 8A

The Allen-Bradley 1771-P4S is a slot-mounted AC power supply engineered for the 1771 Universal I/O platform. It installs directly into a single slot of any 1771 I/O chassis, providing regulated DC power to the backplane. This regulated power is essential for the operation of remote I/O adapters and the various discrete, nalog, and specialty I/O modules residing within the rack, ensuring a stable environment for control logic.

This module accepts a nominal input voltage of 120V AC or 220V AC (field-selectable), providing flexibility for a variety of industrial power distribution systems. It efficiently converts the high-voltage AC input into the precise 5V DC power required by the backplane. The 1771-P4S is capable of delivering a robust 8 Amps of continuous current at 5VDC, making it suitable for powering low-to-medium density 1771 chassis configurations.

The 1771-P4S is built for reliability and ease of use, featuring a front-panel power indicator LED that gives maintenance personnel immediate visual confirmation of the unit’s operational health. It includes integrated overcurrent and thermal protection to safeguard the backplane and all installed modules from potential electrical faults. Its compact, single-slot design allows for maximum use of chassis real estate for I/O modules.

Designed for heavy industrial deployment, the module operates reliably across a temperature range of 0–60°C (32–140°F) and non-condensing humidity levels up to 95%. It is built to withstand the electrical noise and vibration common in factory environments. The power supply is UL listed and CSA certified, meeting the rigorous standards for quality and safety required in global industrial automation applications.

Key Specifications:

  - Function: Backplane Power Supply
  - Input Voltage: 120V AC or 220V AC (Jumper Selectable)
  - Output Current: 8A @ 5VDC
  - Chassis Space: 1-Slot
  - Mounting: 1771 I/O Chassis Slot
  - Platform: 1771 Universal I/O (PLC-5)