Earthing system IT - Earthing system in which the neutral is isolated from the earth or connected to the earth via a high impedance and the various exposed conductive parts are connected to the earth via individual earthing circuits. An alarm must signal the appearance of a first insulation fault. The installation must be de-energized immediately in the event of a second insulation fault.
Wall-less Design - A battery design where the structural support for the cells is formed by an open plastic framework.
Midpoint Voltage - The voltage of a battery midway in the discharge between the start of the discharge and the end voltage.
Thermostat - A temperature sensitive switch.
Hertz - The standard unit of frequency. A frequency of one complete cycle per second is a frequency of one hertz.
Brownout - A steady state RMS voltage under nominal by relatively constant percentage.
Series - The interconnection of cells in such a manner that the positive terminal of the first is connected to the negative terminal of the second, and so on, resulting in increased voltage.
