0

I've got a new UPS for my computer and I experienced the first power outtage today. I had previously tested the battery once fully charged by shutting the appropriate breaker down and it went on battery just fine.

But this morning, I had a power failure that lasted for a couple seconds then came back for 1-2 seconds and went away again. On the second time, everything that was plugged into the battery outlets shutdown.

Could it be that when the power came back and went away again, the UPS was still "switching" its output from battery to wall electricity and I just got unlucky or is my unit possibly defective?

4
  • Based on the information its not possible for us to determine if the unit is defective. It sounds like the unit simply could not keep up, a better quality unit might be able to keep up, make sure you only have the equipment that must be on battery backup hooked up. You can test your unit by using a power strip with a on/off switch and switch it from on to off and watch the status of the unit.
    – Ramhound
    Aug 14, 2013 at 18:38
  • @Ramhound The ups runs from 200-300 W depending on the load on the CPU. It is a 810W unit so I'm guessing that it should keep up for the couple of minutes I need to save and shutdown. Aug 14, 2013 at 18:45
  • Did you system actually shutdown? When this happens to me it normally just takes a few seconds for my system to return to standard operating mode but could to a random person appear to have actually shutdown.
    – Ramhound
    Aug 14, 2013 at 18:52
  • Yup it shutdown, rebooted on its own but as if windows had not shut properly Aug 14, 2013 at 18:52

1 Answer 1

2

Yes, having that happen can confuse the UPS and PC so they don't know what power state to return to.

Most decent UPS allow you to adjust sensitivity and/or recovery times to avoid this.

Sensitivity makes it so you can define how low the power has to go before dropping into Battery mode, and the recovery delay is so that it won't try to turn back on until the power has been back for "X" seconds.

Check the software and manuals that came with your UPS to see if it supports these kind of adjustments, and start adjusting. :)

5
  • Thanks for the quick answer. I see in the software that came with it (Cyberpower 1350pfc) that I can adjust sensitivity. It is on medium by default right now, with low and high also available. I guess I want high sensibility? Also I see no recovery options Aug 14, 2013 at 18:41
  • 1
    @Jean-Sébastien - We can't tell you which setting will prevent the events you describe. Its best if you test it to the best of your ability by using the method I described.
    – Ramhound
    Aug 14, 2013 at 18:50
  • @Jean-Sébastien plus you cannot test a UPS by just cutting off power to it, a good ups also handles brownout situations, and fluxuations in voltage and all. A good on/off switching doesnt do hardly any of the things nasty power from the utility can do :-)
    – Psycogeek
    Aug 14, 2013 at 20:37
  • @Jean-Sébastien The higher the sensitivity the lower the variation required to have the UPS switch modes. so if you're finding it reacting too quickly, you may actually want to lower the sensitivity. Keep in mind too, the UPS isn't turning the machine back on, it's just giving power back, and the machines BIOS' will be set to "return to last state", or "power on" after the power comes back. If this gets interrupted by another power shut down, then the BIOS' will often kick into fail-safe mode and NOT just automatically start again. Aug 14, 2013 at 20:49
  • 1
    IME, this is especially true when set to return to "last state", as dropping power during POST can confuse the BIOS and it will default to thinking the last state was "off". Aug 14, 2013 at 20:50

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .