Computer Power
Occassionally, we get a call about a potential  power problem involving  a computer that keep shutting off, even though it has a UPS (Uninterupptable Power Supply).  The UPS converts its backup battery power to 120 volts when the power goes out.  A simple, normal voltage drop in the house will trigger the UPS to try to run off the battery.  If the battery or UPS unit is bad, you end up with a computer shut-down.  It's normal for a brief voltage drop to occur when a refrigerator or an air conditioner starts.

Helpful Hint:  Test your UPS unit by unplugging it from the wall outlet and see how long the system works.  No UPS is better than a defective UPS.