Case Study: When a Packaging Line Needed More I/O Power
A mid-sized packaging plant ran a CompactLogix system controlling conveyors, sensors, and actuators. Production halted whenever the line expanded because the existing power supply could not support additional I/O modules. The maintenance team needed a power supply that could feed modules on both sides without adding a second unit. They installed the Allen-Bradley 1769-PA2, and the line returned to full capacity with room to grow.
What Is the 1769-PA2?
The Allen-Bradley 1769-PA2 is a CompactLogix I/O power supply designed to deliver regulated power to 1769 series modules. It accepts a wide input range of 85 to 265V AC at 47 to 63 Hz, making it suitable for global industrial environments. The module provides 2.0 A at 5V DC and 0.8 A at 24V DC, supporting both logic and field power needs. With a power supply distance rating of 8, it can power up to eight modules on each side, for a maximum of 16 modules total.
Technical Specifications That Matter
Wide Input Voltage Range
The 85 to 265V AC input range eliminates the need for external transformers or selectable jumpers. This flexibility reduces installation time and inventory costs, especially for facilities that operate across different regions.
Dual Output Current Capacity
The 2.0 A at 5V DC output powers the backplane logic of connected modules. The 0.8 A at 24V DC output supports field devices or communication modules that require 24V power. Together, these outputs cover most CompactLogix I/O configurations without additional power supplies.
Power Consumption and Dissipation
At 120V AC, the module consumes 100 VA; at 240V AC, it consumes 130 VA. Power dissipation is 8 W at 60 °C, which helps engineers calculate enclosure heat loads accurately.
Physical and Environmental Ratings
The 1769-PA2 measures approximately 118 x 70 x 87 mm and weighs 525 g. It has an open-style enclosure and carries c-UL-us, CE, and C-Tick certifications. The module is also UL Listed for Class 1, Division 2 hazardous locations, Groups A, B, C, and D.
Where the 1769-PA2 Fits Best
Packaging and Material Handling
In packaging lines, the 1769-PA2 powers digital and analog I/O modules that control motors, diverters, and photoeyes. Its ability to supply modules on both sides simplifies panel layout and reduces wiring runs.
Water Treatment Facilities
Water treatment plants often run CompactLogix systems in remote cabinets. The wide input range handles voltage fluctuations common in rural areas. The 24V DC output can power transmitters and solenoids directly, reducing component count.
Replacement and Upgrade Projects
When upgrading from older PLC platforms, the 1769-PA2 offers a straightforward migration path. Its DIN rail mounting and standard 14 AWG wiring compatibility let technicians reuse existing enclosures and wiring where possible.
Installation and Setup
Mount the 1769-PA2 on a DIN rail or directly to a mounting plate. Ensure proper grounding using 14 AWG copper wire rated for 90 °C or higher. Keep leads as short as possible to minimize noise. The module requires ventilation space; avoid enclosing it tightly without airflow. For hazardous locations, follow all local codes and the manufacturer’s guidelines.
Maintenance and Reliability
The 1769-PA2 contains an internal fuse that protects against line transients and short circuits. The fuse can be replaced with a Littelfuse 02153.15MXP or Wickmann 19195-3.15A. Inspect the module periodically for dust buildup and secure connections. In high-temperature environments, use enclosure air conditioners to maintain reliable operation.
Compatibility and Integration
The 1769-PA2 integrates directly with CompactLogix controllers and 1769 I/O modules. It supports up to 16 modules when placed centrally, making it ideal for distributed I/O banks. The module works with standard 1769 communication adapters and does not require special configuration.
Selection Guide
Before ordering, verify your system’s power requirements. Calculate the total 5V and 24V current draw of all connected modules. Ensure the 1769-PA2’s 2.0 A and 0.8 A outputs exceed your needs with margin. Check that your input voltage falls within 85 to 265V AC. For assistance, contact SpareTechPLC, a trusted supplier of Allen-Bradley components.
Frequently Asked Questions
How many I/O modules can the 1769-PA2 power?
It supports up to eight modules on each side, for a maximum of 16 modules total.
What is the input voltage range?
The input voltage range is 85 to 265V AC at 47 to 63 Hz.
Can I replace the fuse myself?
Yes, the internal fuse can be replaced with a Littelfuse 02153.15MXP or Wickmann 19195-3.15A. Follow all safety procedures.
Is the 1769-PA2 suitable for hazardous locations?
Yes, it is UL Listed for Class 1, Division 2, Groups A, B, C, and D when installed per applicable codes.
What wire size should I use?
Use 14 AWG solid copper wire rated for 90 °C or higher, with insulation not exceeding 1.2 mm.
