Brownout - A steady state RMS voltage under nominal by relatively constant percentage.
Charger - Device associated with the rectifier and used to supply the battery with the electrical power (DC current) required to recharge and/or float charge the battery, thus ensuring the rated backup time.
Inverter (on-line) - UPS configuration in which the inverter is in series mounted between the mains and the load. All power drawn by the load passes via the inverter. This is the only configuration used for high outputs.
Alloy - A mixture of several other metals or a metal and a non-metal.
MTTF (Mean Time To Failure) - Mathematical calculation of the duration of normal operation of a non-reparable device, i.e. for which a MTBF is not possible. The product, expressed in hours, is an indication on the reliability of the device.
Distortion (individual) - Ratio between the rms value of an nth order harmonic and the rms value of the fundamental.
Earthing system TN - Earthing system in which the exposed conductive parts are interconnected and connected to the neutral. The neutral is connected to the earth. The installation must be de-energized immediately in the event of an insulation fault.