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sharptooth
Asked: 2009-06-22 22:07:32 +0800 CST

What less obvious ways are there to misuse and damage a UPS?

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I've never had an uninterruptible power supply and think of buying one. What not-so-obvious things should I not do to the UPS so that it lives longer?

I don't mean some obvious abuse like dropping/exposing to direct heat/exposing to wrong voltage. I mean less obvious things like its not acceptable to leave an acid battery UPS unplugged for long time after it has been used because some chemical processes start in half-discharged batteries and render the batteries unusable. What other misuses should I know about?

ups electrical-power

7 Answers

  1. The SLA (sealed lead acid) batteries in UPSes shouldn't be left in a discharged state. If they are, sulfates will build up on the plates and their capacity will be reduced. This isn't normally a problem in UPSes, since they're always plugged in and after a power outage will charge the batteries back up when the power comes on. But if you somehow decided to unplug a UPS after the batteries were drained and then left it sitting unplugged for a week, you'd probably notice the battery discharging sooner next time.

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  2. Dont overload it. If it has a nice status screen to see the load on it try to keep it below about 60%

    By discharging it faster will wear out the the battery faster

    Heat, humidity are also bad for it.

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  3. While in college I was moving some servers from one room to another. They all where on a really old UPS which apparently had less protection circuitry then current UPS equipment. I started by disconnecting all the servers from the UPS and moving those. Then without shutting down the UPS I unplugged it from the wall. Sparks started shooting out of the UPS and it literally started bouncing.

    The electronics teacher had a plausible sounding explanation about why something like this would happen given the design of the UPS, but I don't remember enough details to explain it here.

    So the moral of the story is this.

    • When there is no load, always turn off the UPS before disconnecting the power.
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  4. According to the answers to my question over here, it's a bad idea to have a power strip touch it either upstream or downstream.

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  5. Don't plug a UPS into another UPS (i.e. Daisychaining them).

    There's a good discussion on why not to here, or from APC themselves here.

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  6. Best Answer

    If you know you have wonky power (flicker flicker) adjust the sensitivity of the UPS so it doesn't trip for every little flicker. My apartment unit is next to the elevator. I killed a set of batteries in 8 months this way.

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  7. Your main concern should be heat. Don't cover it with a bunch of stuff. Keep the vents clear, and allow airflow.

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