Introduction
Unexpected power loss on a ControlLogix rack can halt a production line and trigger costly downtime. The Allen-Bradley 1756-PSCA2K solves that risk by letting two power supplies feed a single backplane connector. This chassis adapter module mounts on the left side of the chassis and forms the backbone of a redundant power supply system. For plants running continuous processes, it is a practical, ready-to-ship safeguard.
How the 1756-PSCA2K Delivers Redundancy
This ControlLogix chassis adapter combines two power sources into one connection point. If one supply drops offline, the second keeps the backplane energized. That single function protects the entire rack, including every I/O module and controller slot. The cost logic is simple: one adapter versus hours of unplanned stoppage. The module works with the 1756-PA75R and 1756-PB75R power supplies, and only one adapter is needed per system.
Technical Specifications
| Specification | Value |
|---|---|
| Series | ControlLogix |
| Module Type | Chassis Adapter Module for Redundant Power Supply |
| Mounting | Chassis – Left |
| Dimensions | 5.51 x 4.41 x 5.71 inches |
| Weight | 8.1 ounces (0.228 kilograms) |
| Operating Temperature | 32-140 Fahrenheit (0-60 Celsius) |
| Backplane Current (24 Volts) | 125 milliamps |
| Power Dissipation (Max) | 25.7 Watts at 30 Celsius, 21.3 Watts at 60 Celsius |
| Removable Terminal Blocks | 3 RTBs, 1756-TBSH or 1756-TBNH |
| Enclosure | None |
What the Key Ratings Mean in Practice
The 125 milliamp backplane draw at 24 Volts is modest, so the adapter adds little load to your supply budget. Power dissipation falls from 25.7 Watts at 30 Celsius to 21.3 Watts at 60 Celsius, which helps keep cabinet heat predictable in warm plant rooms. The 0-60 Celsius operating range covers most industrial environments without extra cooling. Each of these details lowers the total cost of ownership across the rack’s service life.
Where This Adapter Fits
Redundant power makes sense wherever a stoppage is expensive. In oil and gas terminals, the adapter keeps control racks alive through supply faults. In water treatment and continuous manufacturing, it prevents a single supply failure from stopping the process. Packaging lines with high changeover costs also benefit. In each case, the 1756-PSCA2K turns a potential outage into a non-event.
Installation and Compatibility Notes
The module mounts horizontally on the left side of the chassis and occupies either left-side slot. It uses three removable terminal blocks, the 1756-TBSH or 1756-TBNH. A 1756-CPR2 cable connects it to the power supply, and routing needs at least 5 inches of bend clearance. Plan cabinet space accordingly. The adapter is an open-type device with no enclosure, so it relies on the cabinet for protection. If you are wiring into a networked ControlLogix system, confirm cable and gateway needs with your supplier before ordering.
Sourcing and Availability
Redundancy hardware is only useful when it arrives on time. Oil AutoTech supplies fast-dispatch spares for oil, gas and industrial automation applications, with quick worldwide delivery and hands-on technical selection help. Please verify current lifecycle status and availability with Oil AutoTech before ordering. Contact Oil AutoTech today for pricing and availability.
Frequently Asked Questions
What does the 1756-PSCA2K actually do?
It is a ControlLogix chassis adapter that routes two redundant power supplies into a single backplane connector, protecting the rack from a single supply failure.
Which power supplies work with this module?
The adapter is compatible with the bulletin 1756-PA75R and 1756-PB75R power supplies.
How many adapters does one system need?
Only one 1756-PSCA2K is required to build a redundant power supply system.
What terminal blocks does it use?
It uses three removable terminal blocks, either the 1756-TBSH or the 1756-TBNH.
Where is the module mounted?
It mounts horizontally on the left side of the chassis and can sit in either left-side slot.
