I’ve always believed that using an uninterruptible power supply (UPS) is not only a good way to power a computer system during a power failure but is also a necessary protection against power surges and spikes. But as I recently found out, UPS devices can only do so much.

My own sad story
I recently learned that while UPS devices are great tools for defending your electronics against power-related injuries, if they are connected to a circuit system that isn’t properly configured, your precautions may be for naught.

A few weeks ago, a lightning storm came through my town. All of my PCs were connected to various UPS units, and I considered my equipment safe. As the storm rolled through, a power surge came through our home. My fiancee ran to our home office and yelled for me to follow. None of the machines would turn off.

I made my way to the office and discovered there was smoke coming from the UPS. I quickly unplugged the device from the wall outlet and disconnected all other cords. Eventually it stopped smoking and cooled off. Unfortunately, the UPS was fried and so was my fiancee’s computer, which was connected to it. Strangely, my computer, which was connected to a different UPS, was unharmed.

What caused the UPS to fail?
My fiancee and I recently moved into an older home, in which the electrical wiring isn’t entirely up to code. After the lightning stormed passed, I began checking the wall outlets in my home office and discovered that several were not properly grounded.

The UPS did have a fault indicator that would warn if the device were connected to an improperly grounded outlet—something I had never done, or so I thought. Unfortunately, the day before the storm, I moved my fiancee’s computer and connected the UPS to a different wall outlet in the same room. Because the fault indicator had never activated, and I was in the same room, I assumed the new outlet was grounded properly. I was wrong.

The lessons learned
While I’m now out a few hundred dollars, I’ve at least learned a few lessons.

  • Never assume an outlet is grounded. Even if you’re in a new building, there is always the risk for human error during installation. If you’re in an older building, check every outlet to ensure protection for your machines. A tester will cost you $3 at the local hardware store, compared to several hundred or thousand dollars for a new computer.
  • Always check your UPS to determine if there is a fault in the line (if your UPS has a fault detector). If the UPS detects a fault, use another outlet.
  • Get insurance on your expensive machines. While many UPS devices offer an insurance policy for the equipment they protect, wiring that’s out of date or not up to code will often void these policies.

A shocking experience

If your equipment has ever been damaged by a power-related problem, we want to hear about it. Do you have a tip to help others avoid such troubles? Post a comment or write to Ed Engelking and share your experiences.