Allen-Bradley 1756-PA72
- anadi automation
- Jul 4
- 3 min read
Updated: Jul 5
Allen-Bradley 1756-PA72 – High-Reliability Power Supply for ControlLogix Automation Systems
The Allen-Bradley 1756-PA72 is a robust and dependable power supply module specifically designed for use in ControlLogix chassis-based systems from Rockwell Automation. As part of the Logix 5000 family, the 1756-PA72 plays a vital role in delivering regulated power to all modules housed within the chassis, ensuring smooth and uninterrupted operation of critical industrial control processes. Engineered for durability and performance, this module is well-suited for a wide range of applications across manufacturing, energy, infrastructure, and process industries.
Operating with a nominal input of 120/240V AC, the 1756-PA72 converts incoming AC power into a stable DC output of 1.5 A at 24V DC, which is used to power the backplane of the ControlLogix chassis. It is capable of delivering a maximum output power of 75 Watts, which is sufficient to support multiple modules within the chassis, including communication cards, I/O modules, and processors. This makes the 1756-PA72 ideal for medium to large-scale systems requiring consistent power for demanding automation tasks.
One of the key advantages of the 1756-PA72 is its modular, hot-swappable design. The module can be inserted or removed without shutting down the system, minimizing downtime and supporting continuous operation. This feature is particularly valuable in high-availability environments, where even brief interruptions can result in production losses. Its DIN rail or panel mounting compatibility also adds to the installation flexibility, allowing integrators to optimize space and layout within control cabinets.
In terms of mechanical design, the 1756-PA72 fits into any ControlLogix 1756 chassis, occupying a single slot and providing centralized power distribution. The module is built with rugged industrial-grade components, ensuring high reliability in environments with temperature fluctuations, electrical noise, or vibration. It supports an operating temperature range from 0°C to 60°C and is certified to meet international standards including UL, CE, CSA, and ATEX, making it suitable for deployment in global industrial settings.
To support system diagnostics and maintenance, the 1756-PA72 is equipped with status LEDs on the front panel that indicate the state of the module—such as input OK, output OK, and over-temperature conditions. These indicators provide immediate visual feedback to maintenance personnel, simplifying troubleshooting and system verification during commissioning or after unexpected events.
The power supply does not require any programming, making integration into a ControlLogix system seamless. Once installed, it automatically delivers power to the backplane and all modules connected to it. For systems with larger power demands, additional power supplies can be used in the same chassis or across multiple chassis with interconnectivity. In some configurations, redundant power supply options may be used for applications demanding higher fault tolerance.
If the 1756-PA72 encounters problems—such as voltage irregularities, no power output, overheating, or component failure—it can often be serviced rather than replaced. Professional repair services can diagnose issues like faulty capacitors, transformer breakdown, or power regulation circuit faults. Repairing the unit rather than replacing it can save significant costs, especially in large-scale automation systems with multiple power supply units.
In conclusion, the Allen-Bradley 1756-PA72 is an essential power supply module for the ControlLogix platform, offering stable AC-to-DC power conversion, easy integration, and support for high-reliability automation systems. With its compact design, fault indication, hot-swappable capability, and durable construction, it is a trusted solution for ensuring uninterrupted power to mission-critical industrial control systems. Whether upgrading an existing setup or designing a new automation architecture, the 1756-PA72 is a solid foundation for powering performance and reliability.
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