Allen-Bradley 1756-PA50 ControlLogix Slim Power Supply 85-265VAC

Technical Specifications Breakdown

Key parameters for the 1756-PA50 are listed below for quick reference:

Industry Applications

Discrete Manufacturing Lines

In automotive assembly plants, the 1756-PA50 powers ControlLogix racks that sequence robotic welders and conveyor systems. Its 50W to 60W output range supports up to 8A at 5.1V, enough to run multiple I/O modules in a 1756-A10 chassis. The wide input voltage range (85-265VAC) allows direct connection to global plant voltages without external transformers.

Process Control Skids

Oil and gas skids often operate in high-ambient-temperature environments. The 1756-PA50 delivers full 60W up to 50°C and still provides 50W at 60°C. This thermal derating curve matches the real-world conditions inside a hot control cabinet, preventing unexpected shutdowns during summer peaks.

Installation & Setup Guidance

Mount the 1756-PA50 in the leftmost slot of any compatible 1756 chassis (models 1756-A4, A7, A10, A13, A17, Series A, B, or C). Use 14 AWG (2.5 sq. mm) copper wire rated for 90°C or higher with insulation thickness of 1.2 mm (3/64 in.). Connect the AC input to the terminal block, observing proper grounding per local codes. The supply provides reinforced insulation between input and backplane, tested at 3150V DC for 60 seconds. After wiring, verify the input voltage is within 85-265VAC before powering on.

Maintenance & Reliability

Inspect the power supply annually for dust buildup on the ventilation openings. The 1756-PA50 operates in 0-60°C ambient temperature with 5-95% noncondensing relative humidity. It withstands 30g operating shock, making it suitable for high-vibration environments like metal stamping presses. The hold-up time of 30 ms (at 18-32V DC, 60W) or 40 ms (at 18-32V DC, 50W) ensures the system rides through brief line sags without resetting.

Reliable Power for Your ControlLogix System

Downtime can cost thousands per minute. The Allen-Bradley 1756-PA50 is designed to prevent that. This standard DC power supply mounts on the left side of any compatible 1756 chassis and delivers stable power to the backplane, ensuring your control system runs without interruption.

Compatibility & Integration

The 1756-PA50 is designed exclusively for ControlLogix chassis. It cannot power external devices via terminal blocks. It is compatible with all 1756 chassis revisions A, B, and C. For distributed I/O racks, use the same model to maintain consistent power architecture across the system. The supply provides 1.5A at 1.2V, 2A at 3.3V, and the main 5.1V and 24V outputs listed above.

Selection Guide & Purchasing Advice

When selecting a power supply for your ControlLogix system, match the total backplane current draw of all modules to the 1756-PA50's capacity. For high-density racks, consider the 1756-PA75 or 1756-PB75 if more current is needed. AutoDCSTech stocks genuine Allen-Bradley 1756-PA50 units with full traceability. Contact our engineers for assistance with sizing or compatibility.

Troubleshooting & Common Issues

If the power supply fails to start, first check the AC input voltage at the terminals. A blown fuse inside the supply may require replacement by qualified personnel. If the chassis does not power up, verify that the supply is fully seated in the left slot and the chassis locking tab is engaged. For intermittent resets, measure the input voltage under load to ensure it stays above 85VAC. The 1756-PA50's hold-up time of 30-40 ms can mask brief dips, but persistent low voltage will cause the system to cycle.