Smart-UPS Ultra 5000 showing Internal Fault

[davwapi]

Hello,

We have a Smart-UPS Ultra 5000 with just 1 battery connected. About a month ago, I believe we experienced a power surge which appears to have triggered an internal fault in the UPS. The unit is at a different location, so I am working completely out of the network interface with remote help from the people at that branch.

The battery status main frame is showing there is a fault, but the health of the battery module is OK. 

When trying a self-test, the result is refused and the cause is stating an internal fault. 

The logs of the unit are showing primarily this: "UPS: The remaining runtime is below the NMC's low runtime setting; if power fails, the UPS will be shut down immediately." 
I am thinking about attempting a logic reset as shown is this video: Performing Logic Reset on APC Smart-UPS On-Line SRT Series | Schneider Electric Support

Any ideas or thoughts before I try the reset or go to support?

[Teken]

You’ll need to provide the following logs in their entirety minus any (PII) data: Event, Data, UPS, Diagnostics.

Provide a screen capture of the RBC tab which indicates current state of health and installation date.

Provide a screen capture in the About tab regarding the UPS / NMC.

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[davwapi]

I have attached the logs and screenshots in the zip file. I was unable to find the diagnostics log. The data log seems to only go back around 10-11 days. Also, I was unsure about the RBC tab, but I believe that is the UPS status page which is in a screenshot in that file.

I think we had the power surge either 6/28/2026 or 6/29/2026 We installed the unit around January or February of 2025. 

Let me know if this is what you were asking for or if there is anything else needed. 

[davwapi]

I have attached the logs and screenshots in the zip file. I was unable to find the diagnostics log. The data log seems to only go back around 10-11 days. Also, I was unsure about the RBC tab, but I believe that is the UPS status page which is in a screenshot in that file.

I think we had the power surge either 6/28/2026 or 6/29/2026 We installed the unit around January or February of 2025. 

Let me know if this is what you were asking for or if there is anything else needed. 

[Teken]

Apologies for the late reply as I didn't receive a notification about your feedback. If you haven't done so already based on the logs you provided (Much Thanks).

You need to initiate a RMA for both the main unit and RBC.

The RBC is damaged and the main system isn't charging the cartridge. As an aside based on data log the target site has dirty power which is causing the system to switch from Online to Battery only mode. This cycle has persisted for a very long time and drained the RBC.

The vast majority of Lithium based cells are managed by a BMS (Battery Management System) and its sole job is to manage, control, and protect the individual cells from over / under voltage, charging, balancing, and high / low temperature.

If I was to guess what has happened is the RBC is in a locked state because the BMS did not do its job correctly which is to cut off the low voltage condition before it became critical. As such the BMS has disconnected the RBC from accepting a charge from the system.

You can prove this theory by simply replacing the RBC module and watching to see if the Main System returns to normal operations. You can also take a meter to measure the DC voltage from the connector to see what the output is.

More than likely it will show zero DC voltage as a proper BMS would terminate any output voltage from being seen on the connector output ports. Regardless of all the above both the main system and RBC need to be reviewed by APC Technical Support.

If history is any indicator they will cross ship you an entire new  / refurbished unit as for whatever reason they don't seem to have the ability to ship out a Lithium RBC for basic validation???

Let me know what happens once you initiate contact with APC Technical Support.

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