Why does my Back-UPS XS1200CN not switch to AC power

[HarryP]

I've had an APC Back-UPS XS 1200 for about 12 years and have replaced the battery three times as needed. My last RBC32 battery was installed in late 2023 or early 2024 (the date on the slip that came with the replacement battery is 11/3/2023). I used your shipping instructions to ship the old battery to recycling around 04/22/2024 so I did the battery replacement close to the beginning of 2024 or end of 2023.

Today, my ups started giving four beeps every 30 seconds and refuses to switch to AC power. Any idea what I need to do to fix this? This ups is being used to supply power to my entertainment system (a/v, TV, cable box etc.) and is not normally connected to a PC; I have a second more current ups that I use for my computer. I ran the data cable to the XS1200 to see what it was reporting and it looks OK to me other than the fact it won't switch off battery to AC power. I tried pressing the fuse reset button as well as plugging it into different outlets to no effect. I tried reducing the sensitivity from MEDIUM to LOW but that also made no difference. By this point I don't have any devices plugged into any of the outlets on the back of the ups. The PowerChute utility reports the battery is at 50% charge but I don't think it is charging when plugged into the wall.

So, why won't it switch to AC power but remains on battery power? Is the relatively new battery defective?

The firmware level is 8.g1.DD.

[Teken]

What is the current input voltage and frequency as seen by the UPS via Power Chute Software? If you have RMS Multimeter measure the outlet and compare the same.

You may change the transfer voltage as outlined in the user manual to see if there is a change in behaviour which I have appended here:

https://download.schneider-electric.com/files?p_enDocType=User+guide&p_File_Name=KBOK-757JTT_R0_EN.p...

Keeping in mind if the system is operating correctly and the UPS is in battery only mode it indicates the input power is out of range.

Let me know what the values are and the results of changing the transfer voltage. 👍

[HarryP]

The input voltage drifts between 100 and 105 according to Power Chute; I don't have a Multimeter.

In the Configuration/Voltage setting I have the UPS set to intervene if the voltage is less than 97 or over 139 and for Sensitivity I currently have it set to LOW using Power Chute; it was previously set to MEDIUM because when I had it at HIGH it wouldn't stay on AC power. I've been running it at MEDIUM for about a year.

When I pressed the power button for 10 seconds, all of the lights flashed and then the yellow light flashed 8 times. Not sure what that means. Pressing the power button at that point simply caused the unit to switch on. When I tried this I had the data cable removed from the unit and switched back to my computer, if that would have an impact.

[HarryP]

Well here's something interesting. While switching the data cable between my XS1200 and my newer UPS, the newer one reports an input voltage of 124 while the BX1200 reports it fluctuating around 103 and 105.

[Teken]

You’re going to need to purchase or borrow a True RMS Meter to see what the input voltage / frequency is.

As the system has detected a out of range voltage, frequency, THD, or what people call dirty power. 

Let me know the results 👍

[HarryP]

I think my older ups needs servicing. The newer ups is reporting an input voltage near my expected 120 volt supply. Most likely some capacitors in my old unit have started to fail. Any idea where I can get it serviced? I can't find anything on the APC web site that deals with this. Very poor product support if you ask me.

[Teken · Accepted solution]

Given your unit is 12 years old it would make little sense in repairing the system.

If this is something you’re interested in doing any electronic repair shop can repair the unit.

You’ll need to balance the cost vs value in doing so as the APC FAQ as provided here notes the service life of their hardware is 7-10 years depending upon model.

This is where the hardware should be considered for a replacement or what the industry calls a hardware refresh. 👍

https://www.apc.com/ca/en/faqs/FAQ000265093/

[HarryP]

Thanks for your input. This item can now be closed.