6-29
IM CW500-01EN
Transient Detection
Voltage waveforms are monitored at approximately 40 ksps without gaps
to detect transients every approximately 200 ms. The beginning of a 200
ms period where the first transient is detected is regarded as the start of
the event. The beginning of a later 200 ms period where a transient is no
longer detected is regarded as the end of the event. The detected event
is assumed to continue from the start to the end.
Example of Transient Detection
Threshold
Start of transient
Approx. 200 ms
Duration
End of transient
Measured
waveform
Saved Data
When an event occurs, the event type, the start and end times, and the
measured values are recorded together with the event waveform and rms
variation data. Note that for the event waveform, only the 200 ms period
within the 1-second data update interval is recorded.
Event Waveform
The voltage and current waveform data of all channels in the 200 ms
period (10 cycles for 50 Hz, 12 cycles for 60 Hz) that includes the
event data is recorded (8192 points). If different events occur within
the 1-second data update interval, only the waveform data of the 200
ms period containing the highest priority event is recorded. If several
events of the same time occur within the same period, the one with the
highest (deepest) value is recorded. If the values are also the same, the
one lasting the longest is recorded. There are no priority levels between
connected channels.
[Highest priority]
→
Voltage transient
→
Interruption
→
Dip
→
Swell
→
Inrush
current
6.7 Power Quality
