Allen-Bradley 1756-PA75R ControlLogix Redundant Power Supply 85-265VAC

Technical Specifications Breakdown

Key parameters for the 1756-PA75R are listed below for quick reference:

Industry Applications: Critical Processes

In oil and gas refineries, a momentary power loss can disrupt control loops and compromise safety. This redundant supply ensures that the ControlLogix system remains operational during a primary supply failure. Similarly, in water treatment facilities, the 1756-PA75R supports continuous monitoring and control of pumps and valves. The automatic load sharing feature distributes the load evenly between paired supplies, reducing stress on individual units and extending overall system life.

Installation & Setup Guidance

Installing the 1756-PA75R requires careful planning. You need two units of the same catalog number, a redundant power supply chassis adapter (1756-PSCA2, 1756-PSCA2K, or 1756-PSCA2XT), and a 1756-CPR2 cable to connect each supply to the adapter. The module is panel-mounted and must be placed outside the chassis. Use the solid-state relay on the supply to connect to an input module for status monitoring. This relay provides a contact output that can drive an annunciator (240V AC/DC, 50 mA, resistive only) to alert operators of any power issues.

Maintenance & Reliability

To maintain reliability, inspect the 1756-PA75R periodically for dust accumulation and ensure proper ventilation. The operating temperature range is 0…60 °C (32…140 °F). Keep the enclosure free of obstructions. The non-replaceable fuse is soldered in place; if the fuse blows, the entire supply must be replaced. Regularly verify that the status indicators on both supplies show normal operation. The hold-up time of 2 cycles at 60 Hz (or 2 cycles at 50 Hz) provides a brief window for the backup supply to activate.

Ensuring Uptime with Redundant Power

Industrial automation systems demand uninterrupted operation. A single power supply failure can halt production, causing costly downtime. The Allen-Bradley 1756-PA75R addresses this challenge directly. As a ControlLogix redundant power supply, it pairs with a partner unit to provide continuous power to the chassis. This module is installed outside the chassis and works with a chassis adapter module to enable automatic load sharing between the pair. This design ensures that if one supply fails, the other instantly takes over, keeping your system running without interruption.

Compatibility & Integration

The 1756-PA75R is compatible with ControlLogix chassis models 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17. The surge transient immunity meets IEC 61000-4-5 (±1 kV line-line DM, ±2 kV line-earth CM on signal ports). Conducted RF immunity is 10 Vrms with 1 kHz sine-wave 80% AM from 150 kHz to 80 MHz. This module is a Class 1, Class A appliance per IEC/CISPR 11.

Selection Guide & Purchasing Advice

When selecting a redundant power supply, ensure you order the correct part number. The 1756-PA75R is specifically designed for redundant operation. Verify current lifecycle status and availability with AutoDCSTech before ordering. AutoDCSTech stocks genuine Allen-Bradley products and can help you configure the complete redundant power system, including cables and adapters. Contact our team for fast quotes and expert support.