Electrical power is unfortunately not 100% available and can have fluctuations and surges. A power surge that is strong enough can damage computer power supply and even the mother board and the CPU itself. A power interruption can cause loss of data as computer storage drives may get corrupted if the computer was not properly shutdown.

Computer users should invest in an uninterruptible power supply or UPS which protects the computer from most power related issues. If there is a power failure, the UPS supplies the computer with power long enough for the user to be able to save data and shutdown the computer properly. It also protects the computer from power fluctuation and power surges.

Other equipment can benefit from a UPS as well. For example, a photocopy machine or a printer should also be connected to a UPS to avoid paper jam and ink or toner waste when power is interrupted in the middle of a print job. It can also be used as a backup source of power for critical medical equipment like nebulizers, heart rate monitors and other monitoring equipment.

A UPS is rated by its power capacity in volt-amperes or VA. A 625VA UPS can support about 400Watts of load. The duration in which it can supply power to a computer can be between 10 minutes to 30 minutes depending on the power consumption of the computer.