Maintain ControlLogix Redundancy Without the Downtime
When a redundant power supply chassis adaptor fails on a ControlLogix rack, the whole redundant power scheme is compromised. The Allen-Bradley 1756-PSCA2XT is the chassis adaptor that ties two redundant power supplies into a single power connector on the chassis backplane. For maintenance engineers running oil, gas, and industrial automation lines, keeping a spare on hand is the difference between a quick swap and a stalled process.
This module belongs to the ControlLogix series and is manufactured by Rockwell Automation under the Allen-Bradley brand. It is an open-style device with no enclosure, designed to mount horizontally on the left side of the chassis. Only one adaptor is required to build a redundant power supply system, and it works with the 1756-PA75R and 1756-PB75R power supplies.
Key Parameters That Matter on the Floor
Current capacity is the headline spec here. The module delivers 1.5 Amperes at 1.2 Volts DC, 4 Amperes at 3.3 Volts DC, 15 Amperes at 5.1 Volts DC, and 2.8 Amperes at 24 Volts DC. Those rails feed the backplane, so a healthy adaptor keeps every module in the rack supplied.
Environmental tolerance is built for harsh plant rooms. Operating temperature spans -25 to 70 degrees Celsius, with a maximum surrounding air temperature of 70 degrees Celsius. Nonoperating temperature ranges from -40 to 85 degrees Celsius. Relative humidity follows IEC 60068-2-30 at 5% to 95%, non-condensing. Operating vibration is rated 2 G at 10 to 500 Hertz, with operating and nonoperating shocks of 30 G and 50 G. ESD immunity is 6 kV contact discharge and 8 kV air discharge.
Where This Adaptor Earns Its Place
Redundant power is standard practice in oil and gas control rooms where a single supply failure cannot be allowed to drop the rack. The 1756-PSCA2XT supports that architecture directly by merging two supplies into one backplane feed.
In process skids and remote wellhead panels, the wide operating temperature range and vibration tolerance suit installations that see temperature swings and mechanical movement. In factory automation cells, the same adaptor keeps ControlLogix racks running through planned supply maintenance, because one supply can be serviced while the other carries the load.
Installation and Service Notes
Mount the adaptor horizontally on the left chassis. The left-side cable connects the 1756-CPR2 to the power supply, and that cable needs a minimum bend clearance of 5 inches to route and connect properly. The module ships with three RTBs featuring a 1756-TBSH or a 1756-TBNH.
One safety point deserves attention. Connecting or disconnecting the module cable while the backplane power source is live can cause an electric arc. That arc can result in an explosion or excessive wear on the contacts of the module and its mating connector. Worn contacts raise electrical resistance and can affect module operation. Always de-energize before making or breaking connections, and inspect contacts during scheduled maintenance.
Sourcing and Support
Oil AutoTech supplies industrial automation spares with fast dispatch, worldwide. If you are building or repairing a ControlLogix redundant power system, our team can help confirm the adaptor, cable, and RTB combination your chassis needs. Contact Oil AutoTech today for pricing and availability.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
