MI 2792 PowerQ4 Plus
Theory and internal operation
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Voltage events and alarms - start waveform recorder when either voltage event
or alarm occur
User can perform single or continuous waveform recordings. In continuous waveform
recording, PowerQ4 Plus will automatically initialize next waveform recording upon
completion of the previous one. That means that the following recording will be
initialized only when the first one is being completely saved to the instrument data
memory.
Note:
Saving to the instrument data memory induces “dead time” between contonous
waveform records. Dead time is proportional to record duration and number of selected
recording signals, and usually takes few seconds.
5.1.17 Transient recorder
Transient record function is similar to waveform recorder: it stores a selectable set of
pre- and post-trigger samples on trigger activation, with 10 times higher sampling rate.
Recorder use envelope triggering. Trigger is activated if difference between two
consecutive periods of input voltage signals, is greater than given limit.
Transient recorder stores one cycle of mains signal.
Figure 5.11: Transients trigger detection
Note:
Saving to the instrument data memory induces dead time between consecutive
transient records. Dead time is proportional to record duration and number of selected
recording signals, and usually takes few seconds.
5.1.18 Inrush/Fast recorder
Inrush/Fast recorder is intended for analysis of voltage and current fluctuations during
start of motor or other high power consumers. I
½Rms
values per 10 ms (half period) are
measured and average is logged in each preset interval. Inrush/Fast recorder starts
when the preset trigger occurs.
