Distortion (total) - Ratio between the rms value of all harmonics of a non-sinusoidal alternating periodic value and that of the fundamental. This value may also be expressed as a function of the individual distortion of each harmonic Hn= Yn /Y1.
Separator - An ionic permeable electronically nonconductive spacer or material which prevents electronic contact between electrodes of opposite polarity in the same cell.
Ampere-Hour Capacity - The quantity of electricity measured in ampere-hours (Ah) which may be delivered by a cell or battery under specified conditions.
Harmonic Sinusoidal - Term of the Fourier series expansion of a periodic function. The harmonic (or harmonic component) of the nth order is characterized by - Yn is the rms value of the given harmonic component, w is the angular frequency of the fundamental, related to frequency by - w = 2_f; phin is the phase angle of the given harmonic component at t = 0.
UPS (Uninterruptible Power supply) - An electrical device providing an interface between the main power supply and sensitive loads (computer systems, instrumentation, etc.). The UPS supplies sinusoidal AC power free of disturbances and within strict amplitude and frequency tolerances. It is generally made up of a rectifier/charger and an inverter together with a battery for backup power in the event of a mains failure.
Bypass (manual) - Manually-operated switch used to supply the load via direct connection to utility power during servicing of the UPS system.
Short-Circuit Current (SCC) - The initial value of the current obtained from a battery in a circuit of negligible resistance.