Metal Hydride - An intermetallic compound or alloy in which hydrogen has been absorbed; also, the negative electrode in a nickel-metal hydride battery.
Charge - The conversion of electrical energy, provided in the form of electrical current from an external source, to restore the chemical energy in a cell or battery.
Blackout - A zero voltage condition lasting for more than two cycles. Same as a power failure
Load power - Apparent power Pu that the UPS inverter supplies under given load conditions. It is less than or equal to the rated output Pn. The ratio Pu/Pn defines the % load of the inverter.
Earthing system - System for the interconnection and earthing of exposed conductive parts and neutral. There are three types of neutral system - IT, TN, TT.
Backup time - Time during which the UPS can supply the rated load with nominal-quality power while the mains are down. This time depends on the battery and the efficiency of the UPS. Typical backup ranges from five minutes to several hours.
Discharge - The conversion of the chemical energy of a battery into electrical energy, and the withdrawal of the electrical energy into a load.
