Allen-Bradley 1756-PA75R AC Redundant Power Supply – Obsolete ControlLogix Spare Part

Technical Dossier

Product Details And Specifications

Allen-Bradley 1756-PA75R AC Redundant Power Supply – Obsolete ControlLogix Spare Part

RFQ support for obsolete parts: Send the model number, required quantity and destination so DriveKNMS can confirm sourcing options before quotation.

Technical Specifications

Solving the Discontinued Hardware Crisis

The 1756-PA75R was a core component in ControlLogix redundant power configurations deployed across process industries — oil and gas, water treatment, automotive assembly, and pharmaceutical manufacturing. These systems were engineered for 20–30 year operational lifespans. Rockwell Automation has since discontinued this module, and the recommended migration path involves chassis replacement, I/O rewiring, and full PLC program re-validation.

For a plant manager facing that migration, the real cost is not the hardware. It is the 6–18 months of engineering time, the production freeze during cutover, and the regulatory re-certification required in controlled environments. A single verified 1756-PA75R sourced from DriveKNMS eliminates that entire cost structure and extends the operational life of the existing system by 5 to 10 years — at a fraction of the migration budget.

Condition & Reliability Assurance

Every 1756-PA75R unit processed by DriveKNMS passes a structured 5-step inspection protocol before it is offered for sale:

• Step 1 – Electrolytic Capacitor Assessment: Capacitor aging is the primary failure mode in power supplies of this generation. Each unit is inspected for bulging, leakage, and ESR deviation from specification.
• Step 2 – Firmware Version Verification: Where applicable, firmware revision is confirmed against Rockwell Automation's last published release for this module series.
• Step 3 – Pin and Connector Corrosion Inspection: All backplane connectors and terminal blocks are examined under magnification for oxidation, pitting, or mechanical deformation.
• Step 4 – Functional Load Test: Units are bench-tested under representative load conditions to confirm output voltage stability and redundancy switching behavior.
• Step 5 – Packaging and ESD Protection: Cleared units are repackaged in anti-static materials with desiccant to prevent moisture ingress during transit and storage.

Key Features for System Maintenance

• Drop-in replacement: The 1756-PA75R installs directly into the existing 1756 chassis slot with no backplane modification required.
• No reprogramming required: Power supply replacement does not affect the PLC program, I/O configuration, or network addressing. The controller retains its logic through the swap.
• Avoids engineering reconstruction costs: Substituting this module preserves the existing validated control architecture, eliminating the need for costly system redesign, re-wiring, or re-commissioning.
• Redundancy maintained: The 1756-PA75R supports hot-swap redundant power configurations, meaning replacement can be performed without shutting down the chassis in properly configured systems.

Can this unit be used in a non-redundant configuration?
The 1756-PA75R is designed for redundant power supply slots. Consult your system documentation to confirm chassis slot compatibility before installation.