Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module – DIN Rail Mounted ControlLogix Power Module

Product Overview

The Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module​ is the AC-input chassis power supply for the Rockwell Automation ControlLogix platform. It converts a 120/240 V AC mains source into the regulated 5 V DC backplane power that the controller, I/O modules, communication modules and specialty modules draw upon to operate. As a dedicated, independently mounted supply rather than an integrated part of the controller, the Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module​ gives the ControlLogix architecture its characteristic flexibility: the power capacity, the controller and the I/O population are sized independently, so a chassis can be expanded or reconfigured without replacing the entire control system. The module is mounted on the DIN rail alongside the 1756 chassis and connects to the chassis backplane through the supplied power connector, making it a straightforward field replacement.

Electrically, the Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module​ accepts a universal AC input range of 85–132 V AC or 170–264 V AC at 47–63 Hz, and delivers 5.1 V DC at 7 A, corresponding to approximately 72 W of usable output. This is the figure that governs chassis population: every module installed in the local chassis draws current from this supply, and the sum of those draws must remain below the 7 A rating. The module’s 0.9 A inrush current and soft-start behaviour reduce stress on upstream protective devices and transformer windings, while the 24 V DC nominal system voltage reference provides a stable platform for the backplane regulation. The input voltage sensing is automatic across the two ranges, so the same module can be installed in a 120 V AC North American panel or a 240 V AC international panel without reconfiguration.

The positioning of the Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module​ is that of a foundational infrastructure component. It is not the highest-capacity supply in the family—that distinction belongs to the 13 A 1756-PA75—but its 7 A output is sufficient for a very large proportion of ControlLogix installations, particularly those built around the 7- and 10-slot chassis. For asset owners maintaining long-lifecycle ControlLogix assets, this makes it one of the most strategically important spares to hold on site. A failed power supply produces the same plant-down condition as a failed controller, yet it is far quicker and cheaper to replace. The Allen-Bradley 1756-PA72/C ControlLogix Power Supply Module, supplied as a tested and correctly revision-matched unit, is therefore the economical insurance policy against an otherwise avoidable shutdown, and it protects the substantial investment represented by the existing chassis, I/O configuration and validated control logic.

Technical Specifications