Uninterruptible power supplies provide backup power, protecting equipment from damage in the event of grid power failure.An uninterruptible power supply (UPS) is a type of device that powers equipment, nearly instantaneously, in the event of grid power failure, protecting the equipment from damage.Uninterruptible power supply is widely used in: mining, industry, communications, hospitals, computer business terminals, network servers, network equipment, data storage equipment, emergency lighting system, railway, transportation, power plants, substations, personal computers and other fields.