ABB UNS0868B-P V2 3BHE013940R0002 AC800M Replacement

Product Overview

ABB UNS0868B-P V2 3BHE013940R0002 AC800M Replacement: Seamless DCS Power Supply Upgrade

The ABB UNS0868B-P V2 (part number 3BHE013940R0002) is a dedicated power supply module for the ABB AC800M controller platform, widely deployed in Symphony Plus distributed control systems across power generation, oil & gas, chemical processing, and pulp & paper industries. As legacy AC800M installations age and original modules reach end-of-service, facilities face the critical challenge of sourcing a verified replacement that maintains full electrical and mechanical compatibility without requiring controller reprogramming or rack redesign.

This listing provides a tested, ready-to-ship UNS0868B-P V2 replacement module, sourced from authorized supply chains and verified against ABB’s original hardware specification. Whether you are executing a planned maintenance swap, responding to an unplanned failure, or building a strategic spare-parts inventory for your AC800M-based control system, this module delivers the reliability and traceability your operations demand.

Compatibility Comparison Table

Seamless Upgrade Solutions: Migration Context for AC800M Systems

Upgrading or replacing the UNS0868B-P V2 power supply module is typically one step within a broader AC800M system maintenance or modernization project. In practice, field engineers replacing this module often work alongside several other components in the same control cabinet or rack assembly.

The AC800M controller itself — commonly the PM864A or PM865A processor module — remains the computational core of the system. When the power supply is replaced, it is good practice to simultaneously verify the health of the adjacent TB820V2 Modulebus Modem, which handles communication between the controller and remote I/O clusters. A degraded power supply can cause intermittent Modulebus communication faults that are misdiagnosed as modem failures; replacing the UNS0868B-P V2 often resolves these symptoms entirely.

On the I/O side, the AC800M platform typically interfaces with S800 I/O modules such as the AI810 analog input module, AO810V2 analog output module, and DI810 digital input module mounted on TB810 or TB811 I/O base units. These modules draw regulated power through the rack backplane, making the integrity of the UNS0868B-P V2 supply critical to stable I/O signal quality. During a power supply replacement, it is advisable to inspect all S800 I/O module status LEDs and verify loop integrity on critical analog channels before returning the system to automatic control.

For facilities running Profibus DP fieldbus networks, the CI854A Profibus DP Interface module installed in the AC800M rack communicates with field devices including variable frequency drives, smart valve positioners, and remote I/O stations. Power supply instability is a known cause of Profibus segment errors; a verified UNS0868B-P V2 replacement restores clean backplane power and eliminates this failure mode. Similarly, sites using FOUNDATION Fieldbus H1 should inspect the CI873 FF Interface module for any logged communication errors following a power supply event.

In control cabinets where the AC800M shares enclosure space with ABB ACS800 or ACS880 series variable speed drives, the 24 VDC auxiliary power rail feeding the UNS0868B-P V2 is often sourced from a shared DIN-rail power supply unit. When replacing the module, verify that the cabinet power supply output voltage is within the 24 VDC ±10% tolerance specified for the AC800M platform. An out-of-tolerance supply voltage is a common root cause of premature power module failure and should be corrected before commissioning the replacement unit.

For sites planning a phased migration from an older ABB Master series or Advant OCS platform to Symphony Plus, the AC800M with UNS0868B-P V2 power supply represents the current-generation hardware baseline. Migration projects typically involve installing new AC800M racks alongside legacy hardware, running parallel control during commissioning, and cutting over process loops progressively to minimize production impact. Having verified spare modules — including the UNS0868B-P V2 — on-site before cutover is a standard risk mitigation practice recommended by ABB’s migration methodology.

Retrofit Guidance FAQ

Q: Does replacing the UNS0868B-P V2 require any rewiring?
A: No. The UNS0868B-P V2 connects exclusively through the AC800M backplane connector. There are no external field wiring connections on the power supply module itself. Replacement requires only powering down the controller rack, removing the old module, inserting the new unit, and restoring power.

Q: Will I need to reload the controller program after replacing the power supply?
A: No. The application program resides in the PM864A or PM865A processor module’s non-volatile memory, not in the power supply. Replacing the UNS0868B-P V2 does not affect the stored program. The controller will resume normal execution after power restoration.

Q: Is the V2 revision backward compatible with V1 installations?
A: Yes. The V2 revision is a direct form-fit-function replacement for earlier UNS0868B-P variants. No rack modification, firmware update, or configuration change is required.

Q: What communication protocols are affected during the replacement?
A: The replacement is performed with the controller rack de-energized. Profibus DP, FOUNDATION Fieldbus, and Modulebus communications will be interrupted during the swap. Plan the replacement during a scheduled maintenance window or coordinate with operations to place affected control loops in manual mode prior to the outage.

Q: How much physical space does the module require?
A: The UNS0868B-P V2 occupies a single standard AC800M module slot. No additional cabinet space is required beyond the existing slot vacated by the outgoing module.

Q: Can this module be used in a redundant power supply configuration?
A: The AC800M platform supports redundant power supply configurations using two UNS0868B-P modules in designated slots. This unit is fully compatible with redundant configurations. Consult ABB’s AC800M Hardware Configuration manual for slot assignment requirements.

Warranty Assurance

Every UNS0868B-P V2 3BHE013940R0002 unit shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to dispatch, each module undergoes a pre-shipment functional inspection to verify physical integrity, connector condition, and identification label accuracy against the ABB part number specification.

In the event of a confirmed module defect within the warranty period, TOPNLMS provides replacement support with priority processing. Our after-sales response team is reachable via email and phone to coordinate return logistics, issue replacement authorizations, and provide documentation for your maintenance records.

We maintain bonded inventory of AC800M platform components to support urgent procurement requirements. Express shipping options are available for critical plant situations where minimizing downtime is the primary objective. All units are shipped with appropriate ESD-protective packaging and are accompanied by a packing list and inspection record.

For volume procurement, long-term supply agreements, or project-based BOM fulfillment, contact our industrial sales team to discuss pricing, lead times, and consignment stocking arrangements.