Description

The Allen-Bradley 2085-EP24VDC is a dedicated expansion power supply module designed specifically for Rockwell Automation’s Micro870 programmable logic controller system, part of the broader Micro800 family. This compact module addresses a critical limitation of the Micro870 base controller by providing additional bus power to support up to four expansion I/O modules installed to its right . When the base Micro870 controller is insufficient to power all required I/O modules, the 2085-EP24VDC becomes an essential system component, effectively doubling the maximum expansion I/O capacity from four to eight modules .

The 2085-EP24VDC accepts a nominal 24V DC input from an external Class 2 or LVLC (Limited Voltage Limited Current) power source, and converts it into both 24V DC and 5V DC bus power for the expansion modules on the right side of the chassis . With a maximum input power consumption of 24W and output capability of up to 700mA at 24V (±10%) and 900mA at 5V (±5%), the module delivers sufficient clean power to sustain multiple digital and analog I/O modules . The 2085-EP24VDC is rated for industrial operating temperatures from -20°C to +65°C and complies with rigorous standards including c-UL-us Class I Division 2 hazardous location certification, CE, RCM, and KC approvals . Its open-style enclosure is designed for DIN rail mounting and requires installation within a protective cabinet that meets pollution degree 2 requirements .

Application Scenarios

Consider a packaging machinery OEM that needed to expand a Micro870-based control system from the base four expansion I/O modules to six modules to accommodate additional sensors and actuators for a new product line. The existing Micro870 controller’s internal power budget was insufficient to support the additional modules, and replacing the controller with a higher-capacity model would have required significant reprogramming and recertification. By inserting the Allen-Bradley 2085-EP24VDC between the existing I/O modules and the new expansion modules, the system integrator was able to power the additional four modules without modifying the control program or power supply design. The 2085-EP24VDC simply provided the necessary bus power to the right-side modules while the original controller continued to manage the left-side modules, preserving the existing programming and reducing engineering effort.

In a material handling application, a system integrator needed to deploy a distributed control architecture with a Micro870 controller in a central cabinet and analog modules for load cells and temperature sensors located further down the production line. The Allen-Bradley 2085-EP24VDC was installed in the expansion chain to provide stable, isolated power to the analog modules, ensuring signal integrity and preventing power-related measurement errors. The module’s 10ms ride-through capability at maximum load ensured that brief power disturbances did not cause controller faults or system interruptions . The plant engineer reported that the 2085-EP24VDC installation took less than 15 minutes, and the system has operated without power-related issues for over 18 months.

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