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For the last two days, my Uninterrupted Power Supply (UPS) has failed to function properly. I charged it for 24hrs and again checked that when the power failed my PC was automatically shut down. But when I have power, the system is able draw power through the UPS, even if it fails to supply power when the mains supply does not.Will it cause any harm to my pc?

my questions are-

  1. Is the UPS functioning properly or not?
  2. If not, then will it harm my pc?
  3. If it is functioning, will it regulate direct power to pc without any cause?
  4. Is my UPS battery not working?
  5. What should I do to make my UPS batteries last for at least a year?

I am using FRONTECH UPS 600va (Warranty for both ups and battery is expired) I changed the battery 8 months ago.


migration rejected from Feb 24 '15 at 15:55

This question came from our site for electronics and electrical engineering professionals, students, and enthusiasts. Votes, comments, and answers are locked due to the question being closed here, but it may be eligible for editing and reopening on the site where it originated.

closed as too broad by random Feb 24 '15 at 15:55

There are either too many possible answers, or good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.If this question can be reworded to fit the rules in the help center, please edit the question.

If you have a correctly functioning UPS you should be able to do the following ...

  • Turn on your PC
  • Unplug the UPS from wall-power
    • The UPS should give an audible alarm (and in most cases a visible indication).
    • Your PC should continue to operate normally for several minutes, perhaps tens of minutes.
    • If an extra cable (e.g. USB) is connected and s/w installed, when it's battery charge is getting low, the UPS will eventually signal the PC to perform an orderly shutdown
  • Reconnect the power
    • the UPS alarm should cease
    • the PC should continue to operate (unless the UPS shut it down).
Minor suggestion: if you pull the UPS plug, you lose the ground connection. A better solution is to plug the UPS into a switched power strip. Then switch off the power strip to test. – fixer1234 Feb 24 '15 at 12:44

Sounds like the circuits that should be handling smooth changeover to battery power are not functioning correctly, which isn't all that surprising as these tend to be the first bits to go on older battery systems.

Normal power flow will work fine, but if this is the problem, then the UPS is no better than a surge protector for your machines. It may just be time to get a replacement.

For a 600va UPS, replacements are very affordable these days. here's a nice one from Fellowes for a little over $100 USD.