During an Interruption the voltage sinks well below its nominal value. In 3-phase systems, an Interruption
begins when the voltages on all phases are below threshold and ends when one phase is equal to or
above the interruption threshold plus hysteresis. The trigger conditions for interruptions are threshold
and hysteresis. Interruptions are characterized by duration, magnitude and time of occurrence. The
picture explain this:
Picture:
Characteristics of a voltage interruption
Rapid voltage changes are quick transitions of the RMS voltage between two steady-states. Rapid
voltage changes are captured based on steady voltage tolerance, steady time, minimum compensation
and minimum rate detected. When voltage change exceeds dip or swell threshold, it is considered as Dip
or Swell instead of Rapid Voltage Change. The events list shows voltage step change and transient time.
The detailed events list shows maximum voltage change over nominal voltage. Voltage change trend is
shown in the following pictures:
Picture:
Characteristics of a rapid voltage change
In addition to the voltage, current is also recorded. This allows you to see cause and effect of deviations.
Function key
【
F2
】
accesses event tables where voltage events are listed in sequence.
-59-