Input (V)
time
0
Nominal value = 100V
Threshold value = 80V
Event Start
Event End
Event Duration
Figure 9.1: Waveform of SAG detection for 1P2W system
Note:
(1) For the events to be detected, it is recommended to bring the system voltage and
current for all channels to their corresponding nominal values.
(2) The nominal voltage is the L-L PT Primary value in case of 3P3W system and L-N PT
Primary value in case of 3P4W and 1P2W system.
(3) The nominal current is taken to be CT Primary value.
(4) In case of polyphase systems, sag begins when the voltage of one or more channels
falls below the threshold and ends when the voltage on all measured channels is
above the threshold plus the hysteresis voltage (Figure 9.1). Similarly, the Swell/
Overcurrent event is shown in Figure 9.2.
Example for sag:
Nominal voltage = 100V
Threshold = 80% = 80V
Hysteresis = 2% = 2V
(ThHysteresis) value
= 80+2 = 82V
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Summary of Contents for Master 3440iDL 0.2SS
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