PowerChute Serial shuts down system immediately, regardless of Shutdown Settings choices.

[binky]

Hi.

I have a Back-UPS RS 1500MS2 (s/n 0B2442L07828), purchased new in June of this year (2025). I'm using
PowerChute Serial Shutdown Agent Version 1.3.0.301 under Windows 11 Pro version 24H2.

I have tried these three "Power Outage Configuration" settings

- "Immediately"

- "After the UPS has been on battery for xx seconds"

- "At runtime limit xx seconds"

All three produce the same behavior - when a power event occurs, PCSS immediately initiates a system shutdown.

For example, I currently have "At runtime limit" selected, with a runtime of 360 seconds. UPS Status shows 
UPS Load 24.0%
Runtime Remaining 34 Minutes

I expected that the system would be able to run for as much as 28 minutes on battery before shutting down, but when the laser printer in the next room starts up, the resulting power event causes the UPS to switch briefly to battery, and PCSS immediately initiates a system shutdown. From the log:

10/6/25 15:02:41 No Longer On Battery
10/6/25 15:02:40 On Battery

So, one second on battery was enough to trigger a system shutdown.

Am I doing something wrong?

I've attached a troubleshooting archive file.

Thanks,

-Nick

[Teken]

Perform the following tasks and report back the results:

Disconnect the USB cable from the computer running APC PCSS application. What happens when you disconnect AC Mains from the UPS?!?

If it continues to run and power the connected loads time how long it does so and report back the results.

You may also install the legacy PCPE and report back the results. Please insure PCSS is properly uninstalled and the computer fully rebooted once removed.

You may use this APC Resource Link to download a copy of PCPE here:

https://www.se.com/us/en/download/document/APC_PCPE_310/

Questions Ask . . . 👍

[binky]

Hi Teken.
Thanks for the reply. I performed the experiment you described:

1. Disconnect the USB cable between the Back-UPS and the computer.
2. Unplug the Back-UPS from mains power.

As one might expect, the Back-UPS front panel changed to show running on battery, with 34 minutes of runtime. The computer continued running normally, and did not shut down.

I did not wait for the battery to be exhausted. I'm not sure what that would have accomplished, other than to test the accuracy of the displayed runtime. 

So it appears that PCSS really is behaving as I hypothesized - initiating a shutdown before the configured conditions occur.

Is the preferred solution really simply to consign PCSS to the bin and use different software?

Is the communication protocol the Back-UPS uses published anywhere?

Thanks again,

-Nick

[Teken]

The first step of removing the USB cable and replicating a lights out / grid down event was to isolate and confirm the UPS was not at fault and fully operational. In this case the test affirms the UPS and RBC is fine.

The suggestion to use the legacy PCPE was again to help isolate the problem. Whether it be PCSS, Windows, USB Drivers, Power Management etc.

If PCPE works fine without issues than the next step is to gather logs and submit the same to APC Technical Support to help identify root cause and hopefully offer a break fix / end solve.

My suggestion is simply a troubleshooting (Go / No Go) method to narrow root cause. Along with offering the end user a break fix to use in the interim instead of having nothing to use.

As an aside you may also consider using APCUPSD / NUT software if either do not work as expected.

Questions Ask . . . 👍

[binky]

Hi @Teken.

My apologies - I misunderstood the direction of your inquiry. I've since uninstalled PCSS and installed PCPE from the link you provided. I configured PCPE to "Keep my computer on as long as possible," with shutdown scheduled at five minutes of battery power remaining.

With the USB cable connected from the Back-UPS to the computer, I unplugged the Back-UPS from mains power. Its front panel displayed that it had switched to battery power with about 28 minutes remaining.

The computer did not shut down. The PCPE console reflected the same information, with the "Time Until Shutdown" shown as 23 minutes.

PCPE provides all of the functionality I need, but as it is no longer being maintained, it represents an unknown, but likely increasing, risk. APCUPSD also appears no longer to be maintained. NUT may be a reasonable alternative. 

How does one go about contacting APC/Schneider technical support? This forum is as close as I was able to get. My original post includes a troubleshooting archive file.

Thanks again for your help.

-Nick

[Teken]

Since it appears APC / Schneider has once again decided to update their website the usual and expected links no longer work! 🤦‍♂️

As such please endure using this link and if available select the country required and select Chat, Phone, Email.

https://www.se.com/us/en/work/support/

Questions Ask . . . 👍

[fredkm]

From the logs it doesn't look like PCSS triggers a system shutdown. What I do see is PCSS getting notified by the OS that the system is going into hibernate/sleep:

2025-10-06 15:02:40,281 [PcbeHSM-EventDispatcher] INFO  - [application.PicardApplication.()] stateTransitionNotify signal=XXX_TO_POWERFAIL
2025-10-06 15:02:40,335 [SMTPMailWorker] WARN  - [SMTPMailer.SMTPMailWorker.()] Subject :Dinsdale : On Battery
2025-10-06 15:02:41,368 [PcbeHSM-EventDispatcher] INFO  - [application.PicardApplication.()] stateTransitionNotify signal=POWERFAIL_TO_XXX
2025-10-06 15:02:41,368 [PcbeHSM-EventDispatcher] INFO  - [application.PicardApplication.()] stateTransitionNotify signal=POWERFAIL_TO_ONLINE
2025-10-06 15:02:43,050 [Thread-716] WARN  - [application.PicardApplication.()] Request received from OS to suspend.

Not sure what could cause this. PCSS installation should disable native power management for the UPS,  and OS sleep/hibernate should not be triggered by the UPS switching to battery power. Do you have another battery in your system (apart from the connected UPS)? If so, can you ensure in Windows Power Settings you have configured your OS not going to sleep/hibernate when on battery?