Product Overview
The Allen-Bradley 1756-PA72 is a standard DC power supply engineered for ControlLogix systems. It mounts directly on the left end of a 1756 chassis and plugs into the backplane, delivering reliable power to all connected modules. With an input voltage range of 85-265VAC and a nominal rating of 120/240VAC, this unit adapts to global industrial power standards.
Rated for 5V at 10A, the 1756-PA72 ensures stable operation for demanding automation tasks. Its compact rack-mount design simplifies installation and reduces panel space requirements.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Part Number |
1756-PA72 |
| Module Type |
Standard DC Power Supply |
| Input Voltage Range |
85-265VAC |
| Nominal Input Voltage |
120/240VAC |
| Input Frequency |
47-63 Hz |
| Input Power (Max) |
100VA / 100W |
| Output Power (Max) |
75W @ 0-60°C |
| Current Capacity |
4A @ 3.3VDC; 10A @ 5.1VDC; 2.8A @ 24VDC |
| Isolation Voltage |
250V continuous |
| Max Inrush Current |
20A (per description) / 30A (per spec list) |
| Hold-up Time |
5 cycles @ 85VAC; 6 cycles @ 120VAC; 6 cycles @ 200VAC; 6 cycles @ 240VAC |
| Power Dissipation |
25W @ 0-60°C |
| Dimensions |
14.0 x 11.2 x 14.5 cm (5.51 x 4.41 x 5.71 in.) |
| Weight |
0.95 kg (2.10 lb) |
| Operating Temperature |
0-60°C (32-140°F) |
| Chassis Compatibility |
1756-A4/A, 1756-A7/A, 1756-A10/A, 1756-A13/A, 1756-A17/A, 1756-A4/B, 1756-A7/B, 1756-A10/B, 1756-A13/B, 1756-A17/B, 1756-A4/C, 1756-A7/C, 1756-A10/C, 1756-A13/C, 1756-A17/C |
| Mounting Location |
Left side of 1756 chassis |
| Enclosure |
Open-type (requires external enclosure) |
Note: The inrush current appears as 20A in the full description and 30A in the spec table. Please verify with your system requirements.
Key Features & Benefits
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Wide input range (85-265VAC) enables global deployment without voltage conversion.
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High current capacity (10A at 5.1VDC) supports multiple modules per chassis.
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Robust hold-up time ensures ride-through during brief power interruptions.
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Compact design minimizes panel space and simplifies rack mounting.
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Overcurrent protection safeguards connected equipment.
Industry Applications
The Allen-Bradley 1756-PA72 powers ControlLogix chassis in diverse industries, including automotive assembly lines, food and beverage processing, and material handling systems. In a typical automotive plant, it supplies stable 5V backplane power to PLC modules controlling robotic welders, ensuring consistent cycle times and reducing unplanned downtime.
In a water treatment facility, the 1756-PA72 supports distributed I/O architectures, providing reliable power to remote chassis monitoring pump stations and chemical dosing systems. Its wide input range accommodates fluctuating utility power, maintaining uptime during brownouts.
Installation & Setup
- Mount the 1756-PA72 on the leftmost slot of a compatible 1756 chassis (Series A, B, or C). It does not occupy a module slot.
- Slide the power supply into the chassis until it firmly connects to the backplane.
- Connect the AC input wiring to the terminal block, observing proper phase and neutral connections.
- Secure the unit using the built-in mounting screws to prevent vibration loosening.
- Ensure the chassis is installed inside an appropriate enclosure that meets NEMA 250 or IEC 60529 guidelines, as the power supply has an open-type enclosure.
Maintenance & Reliability
Regularly inspect the 1756-PA72 for dust accumulation and ensure adequate airflow around the unit. Check that all connections remain tight, especially after initial installation. The power supply is designed for long service life, but periodic verification of output voltages (3.3V, 5.1V, 24V) using a multimeter helps confirm healthy operation.
Operating within the specified temperature range (0-60°C) and avoiding overloading beyond 75W output will maximize reliability. If the unit fails, replace it promptly to prevent system downtime.
Compatibility & Integration
The 1756-PA72 is compatible with all ControlLogix chassis listed in the specifications table, covering Series A, B, and C. It works seamlessly with Allen-Bradley ControlLogix processors and I/O modules. This power supply does not support redundant power configurations but can be used in distributed I/O architectures.
Buying Guide
Before purchasing, verify your chassis series and model to ensure compatibility. Confirm your input voltage requirements and total backplane load to ensure the 1756-PA72 meets your power needs. For genuine Allen-Bradley parts and reliable service, choose PLC Source PRO as your supplier.