Voltage Transients
Definition
(ANSI std. 1100-1992) A subcycle disturbance in
the AC waveform that is evidenced by a sharp brief discontinuity
of the waveform. Transients may be of either polarity and
may be of additive or subtractive energy to the nominal waveform.
Transients are also known as spikes or surges and normally are on
the line for only 1/1000th of a second or less (less than 1 millisecond).
They can be from a few to 10,000 volts-peak above or below the voltage
sinewave or data line signal. Voltage
transients normally last only about 50 microseconds and current
transients last typically 20 microseconds according to the ANSI
C62.41-1991 which is the standard for transients in facilities operating
under 600 Volts RMS. Transients
can either be of the oscillatory or impulse types.
