1756-PA72K Allen-Bradley ControlLogix AC Power Supply

1756-PA72K Allen‑Bradley ControlLogix AC Power Supply Module

Product Introduction

The 1756-PA72K provides reliable AC power to your ControlLogix chassis. Allen‑Bradley designed this module for non-redundant applications. It accepts a nominal input of 120-240V AC with an operating range of 85-265V AC. The module then delivers 75 watts of output power at 60 °C. Four DC voltage rails supply your processor and I/O modules. Additionally, the 1756-PA72K offers surge transient immunity and protection against conducted and radiated RF interference.

Key Technical Specifications

The 1756-PA72K operates at an input frequency of 47-63 Hz. Maximum input power reaches 100 VA (100 watts). Inrush current is limited to 20 amperes maximum. Hold-up time varies by input voltage: 5 cycles at 85V AC, and 6 cycles at 120V, 200V, or 240V AC. The module's current capacity includes four outputs:

• 1.5A at 1.2V DC

• 4.0A at 3.3V DC

• 10.0A at 5.1V DC

• 2.8A at 24V DC

Furthermore, the 1756-PA72K weighs approximately 1.1 kg. Its dimensions are 14.0 x 11.2 x 14.5 cm (5.51 x 4.41 x 5.71 inches). The module uses an open-type enclosure, so you must install it inside a suitable cabinet.

Chassis Compatibility and Mounting

You must install the 1756-PA72K in the leftmost slot of any compatible 1756 chassis. Supported chassis include the 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17. These can be Series A, B, or C. The module directly plugs into the backplane without any additional cabling. This simple installation saves panel space and reduces wiring errors.

Wiring Requirements

For safe and reliable operation, use 14 AWG (2.5 mm²) copper wire. Both solid and stranded types are acceptable. The insulation must be rated at 90 °C (194 °F) or higher with a maximum thickness of 1.2 mm (3/64 inches). Wire category for power ports is 1. Tighten the conductor screws to 0.56 N·m (5 lb·in). Do not overtighten, as this may damage the terminal block.

Environmental and Mechanical Ratings

The 1756-PA72K operates in temperatures from 0 to 60 °C (32 to 140 °F). Storage temperature ranges from -40 to 85 °C (-40 to 185 °F). Relative humidity tolerance is 5% to 95% non-condensing. For vibration, the module withstands 2G at 10-500 Hz. Operating shock rating is 30G, while non-operating shock reaches 50G. The module complies with the T4 North American temperature code.

Surge and Immunity Features

The 1756-PA72K includes robust immunity features. It protects against surge transients, conducted RF, radiated RF, and electrostatic discharge (ESD). These features make it suitable for industrial environments with electrical noise. You do not need external filtering in most cases. However, always follow proper grounding practices for best performance.

Installation Guidelines

First, ensure the chassis is completely powered off. Next, align the 1756-PA72K with the leftmost slot guides. Slide the module in until the top and bottom latches click firmly. Then, connect the AC supply wires to the terminal block. Use copper conductors only. Tighten screws to exactly 0.56 N·m. Additionally, verify that the surrounding temperature does not exceed 60 °C. Finally, apply power and check that the green status LED illuminates.

For safe operation, mount the 1756-PA72K inside an enclosure that requires a tool for access. This prevents accidental contact with live terminals. Also, keep the area around the module clear for proper airflow.

Typical Applications

You will find the 1756-PA72K in manufacturing lines, packaging machines, and material handling systems. It also suits process control skids, water treatment plants, and conveyor systems. For non-redundant applications, this power supply provides reliable DC power at a reasonable cost. Its 75W output handles most small to medium ControlLogix configurations.

Packaging List

• 1756-PA72K power supply module – 1 unit

• Removable terminal block (power connector) – 1 piece

• Installation instruction sheet – 1 copy

Note: No certificates or warranty documents are included in the package.

Shipping

We ship via FedEx, UPS, or DHL. Standard transit time is 3–7 business days depending on your destination.

Frequently Asked Questions (FAQ)

1. Can I use the 1756-PA72K with a Series C chassis?
Yes. The 1756-PA72K works with Series A, B, and C chassis. Check your chassis model number for confirmation.

2. What happens if the input voltage drops below 85V AC?
The module may shut down or become unstable. Hold-up time provides 5 cycles of operation at 85V AC before output drops.

3. Is the 1756-PA72K redundant?
No. This is a non-redundant power supply. For redundancy, consider the 1756-PA75R or 1756-PB75R models.

4. What wire size should I use for the 1756-PA72K?
Use 14 AWG copper wire (solid or stranded). Insulation must be rated for 90 °C minimum.

5. Does the 1756-PA72K require an external fuse?
Yes. Install an external fuse or circuit breaker rated for 250V AC, 10A maximum, on the input power lines.