The Allen-Bradley 1769-PA4, also cataloged as the 1769-PA4 I/O Power Supply, operates as a dedicated hardware component for localized voltage regulation within CompactLogix control platforms. The module executes AC-to-DC conversion, providing 4.0 A at 5 VDC and 2.0 A at 24 VDC to support system backplane requirements and integrated I/O modules.

Hardware Specifications

Deterministic Industrial Control Integration

The 1769-PA4 is designed to maintain backplane bus communication velocity by ensuring stable voltage levels across the CompactLogix system. Proper power distribution minimizes noise on the backplane, supporting deterministic network performance for EtherNet/IP and related communication protocols. Firmware flash compatibility across the ControlLogix and CompactLogix ecosystems is maintained through this module's ability to provide a consistent electrical environment, preventing logic execution errors during I/O density scaling or high-speed data processing cycles.

Field Installation Guidelines

• Mounting: Mount the power supply on a clean, grounded panel or 35 mm DIN rail, ensuring space for adequate thermal convection.

• Wiring: Utilize 22 to 14 AWG copper wire for all primary input connections; verify terminal tightness to ensure low-impedance contact.

• Selection: Position the input voltage selector switch to match the local AC supply (85-265 V AC range) before applying power.

• Grounding: Terminate the chassis ground terminal to a low-impedance earth ground to mitigate electromagnetic interference (EMI).

Ordering info

• Includes: One (1) 1769-PA4 AC Power Supply module.

• Documentation: Installation and technical instruction manual.

• Compatibility: Supports a maximum of 16 I/O modules, with a distance rating of 8 modules on either side of the supply.

Frequently Asked Questions

Q: Does the 1769-PA4 support hot-swapping?

A: No, the power supply is not designed for hot-swapping. Isolate all power sources before performing maintenance or module installation.

Q: How is the maximum module capacity calculated?

A: The module has a distance rating of 8; I/O modules must be configured so that the electrical load does not exceed the power supply's backplane capacity, with a maximum of 16 modules total in the configuration.

Q: What action is required if the AC input voltage changes?

A: The input voltage selector switch must be manually set to the correct range (85-265 V AC or 170-265 V AC) based on the supplied line voltage before energizing the unit.