An Uninterruptible Power Supply (“UPS”) is a hardware device containing battery cells & electric circuitry. A UPS provides temporary power in the event of a power failure, allowing a user to continue working for a short while and enough time to shut down gracefully, thereby preventing possible loss of work. It will also assist in preventing the possible corruption of software & data.
A UPS plugs into an electric wall socket (ESKOM) & the devices (usually the computer and monitor) plug into the UPS — the UPS charges while the power is on.
A UPS provides “clean” power, protecting against dips (“brown-outs”) & surges in the main power source. It also prevents power surges from physically damaging hardware.
Uninterruptible Power Supplies are rated in volt-amperes (VA) with a 600VA unit commonly being used for a small PC & monitor and a 1kVA unit for a server.
A UPS will usually beep audibly when it has lost mains power and is operating on battery power. A large UPS connected to a server may have a data connection to supply operational data to monitoring software installed on the server.