Current (inrush) - Temporary current observed in a network when electrical devices are energized, generally due to the magnetic circuits of the devices. The effect is measured by the current's maximum peak value and the rms current value it generates.
Earthing system - System for the interconnection and earthing of exposed conductive parts and neutral. There are three types of neutral system - IT, TN, TT.
Distortion (individual) - Ratio between the rms value of an nth order harmonic and the rms value of the fundamental.
Charge Control - Technique for effectively terminating the charging of a rechargeable battery.
Hertz - The standard unit of frequency. A frequency of one complete cycle per second is a frequency of one hertz.
Power source (safety) - Power source for loads defined as critical by applicable safety regulations. This supply must not be affected by a mains failure and is generally separate from other supplies.
Intermittent Test - A test during which a battery is subjected to alternate periods of discharge and rest according to a specified discharge regime.