1756-PSCA2K Allen-Bradley Redundant Power Adapter

Allen-Bradley 1756-PSCA2K ControlLogix Chassis Adapter for Redundant Power

Product Introduction

The 1756-PSCA2K from Allen‑Bradley is a specialized chassis adapter module. Its primary job is to enable redundant power supply configuration for ControlLogix systems. You mount this module on the left side of the chassis. Then it connects two power supplies into a single backplane power connector.

Why use redundant power? Downtime costs money. If one power supply fails, the second one immediately takes over. The Allen-Bradley 1756-PSCA2K makes this possible. It works exclusively with the 1756-PA75R (AC) and 1756-PB75R (DC) power supplies.

Furthermore, this module is an open-type device. It requires installation inside a suitable enclosure. Only one 1756-PSCA2K is needed per redundant power system. Without it, you cannot build a proper ControlLogix Redundant Power Supply System.

Technical Specifications

• Manufacturer: Allen‑Bradley

• Series: ControlLogix

• Module Type: Chassis Adapter for Redundant Power Supply

• Mounting position: Left side of chassis (horizontal)

• Backplane current (24V): 125 mA

• Power dissipation (max): 25.7 W at 30°C, 21.3 W at 60°C

• Weight: 8.1 ounces (0.228 kg)

• Dimensions: 5.51 x 4.41 x 5.71 inches

• Shipping dimensions: 1.38 x 6 x 5.81 inches

• Removable Terminal Blocks: 3 x RTB (1756‑TBSH or 1756‑TBNH)

• Compatible power supplies: 1756‑PA75R, 1756‑PB75R

Current Capacity Ratings

The 1756-PSCA2K provides the following current capacity to the backplane:

• 1.2V DC: 1.5 Amps

• 3.3V DC: 4.0 Amps

• 5.1V DC: 15.0 Amps

• 24V DC: 2.8 Amps

Environmental Ratings

• Operating temperature: 0°C to 60°C (32°F to 140°F)

• Storage temperature: -45°C to 60°C

• Enclosure: None (open-type device)

• Mounting: Horizontal only, left chassis position

Installation Guide

First, ensure the ControlLogix chassis is completely powered off. Then locate the leftmost slot of the chassis. The 1756-PSCA2K must mount horizontally in this specific position. Next, insert the module firmly until it locks into place.

After mounting the adapter, connect your redundant power supplies. Use the 1756-CPR2 cable to link each power supply to the Allen-Bradley 1756-PSCA2K. Pay attention to cable bending. You need a minimum clearance of 5 inches to route and connect the cables properly.

Finally, attach field-side wiring using the three RTBs. Choose either 1756-TBSH or 1756-TBNH terminal blocks. Then power up the system and verify the redundant configuration.

Important Notes

Only one 1756-PSCA2K is required per redundant power system. Do not install multiple adapters in the same chassis. Also, this module is not a power supply itself. It is an adapter that manages two external power supplies. Removing or inserting the module while power is on may cause electrical arcing. Always disconnect power first.

Packaging List

• 1 x 1756-PSCA2K Chassis Adapter Module

• 1 x quick reference guide

• RTBs are sold separately (1756‑TBSH or 1756‑TBNH)

• 1756-CPR2 cable is sold separately

• No certificate or warranty documents included

Shipping Methods

We ship worldwide using Fedex, UPS, or DHL. Tracking number provided within 24 hours.

Frequently Asked Questions (FAQ)

1. Which power supplies work with the 1756-PSCA2K?
It works exclusively with 1756-PA75R (AC input) and 1756-PB75R (DC input). Standard power supplies are not compatible.

2. Can I mount this module in any other chassis slot?
No. The Allen-Bradley 1756-PSCA2K must mount on the left side of the chassis. Other slots will not function correctly for redundant power.

3. Do I need more than one adapter for a redundant system?
No. A single 1756-PSCA2K connects two redundant power supplies. One adapter is sufficient for the entire chassis.

4. What is the minimum cable bend radius?
You need at least 5 inches of clearance for the 1756-CPR2 cable. This allows proper routing and connection without damaging the cable.

5. Does this module provide power by itself?
No. It is an adapter only. The 1756-PSCA2K distributes power from external supplies to the backplane. It does not generate or convert power on its own.