Allen-Bradley 1756-PA72 ControlLogix Power Supply Module

Product Overview

The Allen-Bradley 1756-PA72 is a standard AC power supply module part of Rockwell Automation's ControlLogix series, designed to provide stable and reliable DC power to ControlLogix chassis, modules, and associated devices in industrial automation systems. As a critical power component in distributed control architectures, this module ensures consistent power delivery to support the operation of processors, I/O modules, and communication adapters within the ControlLogix ecosystem.

The 1756-PA72 is engineered to operate in challenging industrial environments, delivering high reliability and exceptional performance. Its robust design allows for seamless integration into existing systems, providing the necessary power infrastructure for automation applications across manufacturing, process control, and infrastructure management. The module's wide input voltage range and comprehensive protection features make it a versatile solution for diverse industrial power requirements.

Key Features and Capabilities

Power Specifications and Performance

The 1756-PA72 features a wide input voltage range of 85-265V AC, making it adaptable to various regional power standards and fluctuating power conditions without requiring additional voltage conversion equipment

.

The module provides multiple output voltages with substantial current capacities:

• 1.2V DC at 1.5A

3.3V DC at 4.0A

5.1V DC at 10.0A

24V DC at 2.8A

.

Design and Physical Characteristics

The 1756-PA72 boasts a compact form factor with dimensions of 14.0 × 11.2 × 14.5 cm (5.51 × 4.41 × 5.71 inches) and a weight of approximately 0.95 kg (2.10 pounds)

. This standardized size ensures seamless integration with ControlLogix chassis systems.

The module employs an open-style enclosure design that provides basic protection while allowing for adequate heat dissipation. However, it requires installation in a suitable protective enclosure to safeguard against industrial contaminants, dust, moisture, and physical damage

.

Protection and Safety Features

To ensure operational reliability, the 1756-PA72 incorporates comprehensive electrical protection including:

• Over-current protection with a maximum current rating of 15A

• Enhanced insulation tested at 3500V DC for 60 seconds

• Continuous voltage isolation rated at 250V

• Surge immunity with a maximum inrush current handling of 20A

• The module holds multiple international safety certifications including CE, CSA, C-TICK, GOST, KC, MARINE, NRTL, and UL, ensuring compliance with global safety standards for industrial equipment

  .

  Environmental Robustness

  The 1756-PA72 is designed to operate effectively in a temperature range of 0°C to 60°C (32°F to 140°F) and can withstand storage temperatures from -40°C to 85°C (-40°F to 185°F)

  . It operates reliably at relative humidity levels of 5% to 95% (non-condensing), making it suitable for various industrial environments

  .

  The module demonstrates excellent vibration resistance (2G at 10-50 Hz) and shock tolerance (30G operational, 50G non-operational), ensuring reliable performance in challenging industrial conditions

  .

  Technical Specifications

  The following table summarizes the key technical specifications of the Allen-Bradley 1756-PA72 power supply module:

   

   

  Feature Category	Specification Detail
  Manufacturer	Rockwell Automation/Allen-Bradley
  Part Number	1756-PA72
  Module Type	AC Power Supply Module
  Input Voltage Range	85-265V AC
  Input Frequency	47-63 Hz
  Nominal Input Voltage	120/240V AC
  Output Voltage 1	1.2V DC @ 1.5A
  Output Voltage 2	3.3V DC @ 4.0A
  Output Voltage 3	5.1V DC @ 10.0A
  Output Voltage 4	24V DC @ 2.8A
  Rated Output Power	75W @ 0-60°C (32-140°F)
  Power Consumption	25W @ 0-60°C (32-140°F)
  Heat Dissipation	85.3 BTU/hour
  Max Inrush Current	20A
  Overcurrent Protection	15A maximum
  Isolation Voltage	250V continuous
  Enhanced Insulation	3500V DC for 60 seconds
  Operating Temperature	0°C to 60°C (32°F to 140°F)
  Storage Temperature	-40°C to 85°C (-40°F to 185°F)
  Relative Humidity	5% to 95% (non-condensing)
  Vibration Resistance	2G @ 10-50 Hz
  Shock Resistance	30G (operational), 50G (non-operational)
  Dimensions (H × W × D)	14.0 × 11.2 × 14.5 cm (5.51 × 4.41 × 5.71 inches)
  Weight	0.95 kg (2.10 lbs)
  Certifications	CE, CSA, C-TICK, GOST, KC, MARINE, NRTL, UL
  Compatible Chassis	1756-A4, A7, A10, A13, A17 (Series A, B, or C)

  System Configuration and Installation

  Hardware Integration

  The 1756-PA72 module is designed for simple installation in the leftmost position of compatible ControlLogix chassis, including 1756-A4, A7, A10, A13, and A17 models (Series A, B, or C)

  . This dedicated positioning ensures optimal power distribution throughout the chassis backplane.

  The module features a dedicated slot allocation that resides outside the main rack, not occupying a valuable ControlLogix slot that could otherwise be used for functional modules

  . This design maximizes the available space for I/O modules, processors, and communication adapters.

  Power Management

  The 1756-PA72 demonstrates exceptional hold-up time characteristics across various input voltages:

  • 5 cycles at 85V AC, 50/60 Hz

• 6 cycles at 120V AC, 50/60 Hz

• 6 cycles at 200V AC, 50/60 Hz

• 6 cycles at 240V AC, 50/60 Hz

This robust hold-up time ensures that the system maintains operation during brief power interruptions or fluctuations, enhancing overall system reliability.

Redundancy Considerations

Unlike some higher-end power supply modules in the ControlLogix family, the 1756-PA72 does not support redundant power configurations

. This important consideration makes it suitable for applications where redundancy is not a critical requirement or where budget constraints necessitate a standard power solution.

Applications

The 1756-PA72 power supply module is suitable for a wide range of industrial automation applications:

• Manufacturing Automation: Providing reliable power to control systems in automotive, electronics, and consumer goods production facilities.

• Process Control: Supporting critical processes in chemical, pharmaceutical, and food processing plants where stable power is essential for continuous operation.

• Material Handling Systems: Powering control systems for conveyor networks, sorting equipment, and automated storage/retrieval systems.

• Energy Management: Integrating into power distribution and management systems for monitoring and control applications.

• Infrastructure Automation: Supporting building management systems, water treatment plants, and other critical infrastructure applications.

Its wide input voltage range and robust design make it particularly valuable in regions with unstable power grids or industrial environments with challenging electrical conditions.

Comparison and Considerations

When selecting the 1756-PA72 module, consider the following aspects:

• Non-Redundant Operation: The module does not support redundant power configurations; applications requiring high availability may need to consider redundant power supply options

• .

• Environmental Protection: The open-style design requires installation in a suitable protective enclosure for harsh industrial environments

• .

• Power Requirements: Ensure the 75W maximum output power meets the needs of your specific ControlLogix configuration.

• Chassis Compatibility: Verify compatibility with your specific ControlLogix chassis model (A4, A7, A10, A13, or A17) and series (A, B, or C)

• .

• Certification Requirements: The module's numerous international certifications make it suitable for global deployments, but always verify specific regional compliance requirements.

For applications requiring different power characteristics, Rockwell Automation offers other power supply modules in the 1756 series with varying capabilities, including redundant power supply options.

Conclusion

The Allen-Bradley 1756-PA72 ControlLogix Power Supply Module is a robust and reliable solution for industrial automation applications requiring stable power delivery to ControlLogix systems. Its wide input voltage range, multiple output voltages, and comprehensive protection features make it suitable for diverse applications across manufacturing, process control, and infrastructure automation.

With excellent hold-up time characteristics, international safety certifications, and easy integration into ControlLogix chassis, the 1756-PA72 helps ensure system reliability and reduce downtime. Its rugged design provides dependable performance even in challenging industrial environments, making it a valuable component in modern automation systems.

For engineers and system integrators seeking a cost-effective power solution with proven reliability and seamless integration with Allen-Bradley ControlLogix systems, the 1756-PA72 represents an excellent choice that combines performance, durability, and the quality characteristic of the Allen-Bradley brand. While it doesn't offer redundancy capabilities, its robust design and reliable performance make it a workhorse power solution for a wide range of industrial automation applications.